Therapeutic Toxic Class

A)

Specific Substances

A)

1.2.1) MOLECULAR FORMULA
1) C6-H8-N2.Cl-H

Life Support

A)

Clinical Effects

0.2.1)

A) Phenylhydrazine hydrochloride can be irritating to the eyes, skin, nose, mucous membranes, throat, and respiratory tract. It is a hemolytic agent and a methemoglobin inducer. Nausea, vomiting, anorexia, hypoglycemia, CNS stimulation, and coma can occur with acute exposure. Liver and kidney damage can also occur. Phenylhydrazine hydrochloride is an experimental animal carcinogen, and phenylhydrazine is a suspected human carcinogen.
B) The hydrochloride would be expected to produce milder local effects, but similar systemic effects as the free base.

0.2.3)

A) Fever may occur.

0.2.4)

A) Phenylhydrazine hydrochloride is an eye irritant. Facial edema, conjunctivitis, salivation, and headache have been reported with hydrazine exposure.

0.2.5)

A) Hypotension may occur.

0.2.6)

A) Respiratory irritation, dyspnea, or cyanosis can occur from breathing phenylhydrazine hydrochloride dust. Acute exposure to low concentrations of hydrazines may cause delayed death (days) and produce bronchial mucous destruction and pulmonary edema.

0.2.7)

A) CNS stimulation, excitability, tremors, convulsions, and coma have occurred.

0.2.8)

A) Nausea and anorexia are common.

0.2.9)

A) Fatty degeneration and occasional hepatic necrosis may occur.

0.2.10)

A) Renal damage, possibly secondary to hemolysis, may occur from phenylhydrazine.

0.2.13)

A) Hemolysis, thrombosis, methemoglobinemia, and anemia may occur.

0.2.14)

A) Skin irritation has been reported in humans. Necrosis occurred at the site of application in rats and rabbits.

0.2.15)

A) Arthralgias have been reported.

0.2.16)

A) Hypoglycemia or hyperglycemia may occur with hydrazines, depending on the glycogen reserves in the liver.

0.2.20)

A) At the time of this review, no data were available to assess the potential effects of exposure to this agent during pregnancy or lactation.

0.2.21)

A) Phenylhydrazine is a suspected human carcinogen.

0.2.22)

A) Phenylhydrazine hydrochloride can be hazardous by inhalation, contact with the skin, or ingestion. Hydrazines exert at least part of their toxicity by generation of pyridoxine deficiency.
B) Cumulative toxicity may occur, due to hemolysis.

Laboratory Monitoring

A)

B)

C)

Treatment Overview

0.4.2)

A) Do NOT induce emesis.
B) GASTRIC LAVAGE: Consider after ingestion of a potentially life-threatening amount of poison if it can be performed soon after ingestion (generally within 1 hour). Protect airway by placement in the head down left lateral decubitus position or by endotracheal intubation. Control any seizures first.

1) CONTRAINDICATIONS: Loss of airway protective reflexes or decreased level of consciousness in unintubated patients; following ingestion of corrosives; hydrocarbons (high aspiration potential); patients at risk of hemorrhage or gastrointestinal perforation; and trivial or non-toxic ingestion.

C) ACTIVATED CHARCOAL: Administer charcoal as a slurry (240 mL water/30 g charcoal). Usual dose: 25 to 100 g in adults/adolescents, 25 to 50 g in children (1 to 12 years), and 1 g/kg in infants less than 1 year old.
D) SEIZURES: Administer a benzodiazepine; DIAZEPAM (ADULT: 5 to 10 mg IV initially; repeat every 5 to 20 minutes as needed. CHILD: 0.1 to 0.5 mg/kg IV over 2 to 5 minutes; up to a maximum of 10 mg/dose. May repeat dose every 5 to 10 minutes as needed) or LORAZEPAM (ADULT: 2 to 4 mg IV initially; repeat every 5 to 10 minutes as needed, if seizures persist. CHILD: 0.05 to 0.1 mg/kg IV over 2 to 5 minutes, up to a maximum of 4 mg/dose; may repeat in 5 to 15 minutes as needed, if seizures continue).

1) Consider phenobarbital or propofol if seizures recur after diazepam 30 mg (adults) or 10 mg (children greater than 5 years).
2) Monitor for hypotension, dysrhythmias, respiratory depression, and need for endotracheal intubation. Evaluate for hypoglycemia, electrolyte disturbances, and hypoxia.

E) ACUTE LUNG INJURY: Maintain ventilation and oxygenation and evaluate with frequent arterial blood gases and/or pulse oximetry monitoring. Early use of PEEP and mechanical ventilation may be needed.
F) METHEMOGLOBINEMIA: Determine the methemoglobin concentration and evaluate the patient for clinical effects of methemoglobinemia (ie, dyspnea, headache, fatigue, CNS depression, tachycardia, metabolic acidosis). Treat patients with symptomatic methemoglobinemia with methylene blue (this usually occurs at methemoglobin concentrations above 20% to 30%, but may occur at lower methemoglobin concentrations in patients with anemia, or underlying pulmonary or cardiovascular disorders). Administer oxygen while preparing for methylene blue therapy.
G) METHYLENE BLUE: INITIAL DOSE/ADULT OR CHILD: 1 mg/kg IV over 5 to 30 minutes; a repeat dose of up to 1 mg/kg may be given 1 hour after the first dose if methemoglobin levels remain greater than 30% or if signs and symptoms persist. NOTE: Methylene blue is available as follows: 50 mg/10 mL (5 mg/mL or 0.5% solution) single-dose ampules and 10 mg/1 mL (1% solution) vials. Additional doses may sometimes be required. Improvement is usually noted shortly after administration if diagnosis is correct. Consider other diagnoses or treatment options if no improvement has been observed after several doses. If intravenous access cannot be established, methylene blue may also be given by intraosseous infusion. Methylene blue should not be given by subcutaneous or intrathecal injection. NEONATES: DOSE: 0.3 to 1 mg/kg.
H) Concomitant use of methylene blue with serotonergic drugs, including serotonin reuptake inhibitors (SRIs), selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), norepinephrine-dopamine reuptake inhibitors (NDRIs), triptans, and ergot alkaloids may increase the risk of potentially fatal serotonin syndrome.
I) Pyridoxine may be antidotal. Dose of pyridoxine is 25 mg/kg, 1/3 given IM and 2/3 given IV over 3 hours. Increase the dose by 25 mg/kg every 5 to 10 minutes to a maximum of 300 mg/kg/dose for continuing CNS symptoms (seizures, coma).

0.4.3)

A) INHALATION: Move patient to fresh air. Monitor for respiratory distress. If cough or difficulty breathing develops, evaluate for respiratory tract irritation, bronchitis, or pneumonitis. Administer oxygen and assist ventilation as required. Treat bronchospasm with an inhaled beta2-adrenergic agonist. Consider systemic corticosteroids in patients with significant bronchospasm.
B) SEIZURES: Administer a benzodiazepine; DIAZEPAM (ADULT: 5 to 10 mg IV initially; repeat every 5 to 20 minutes as needed. CHILD: 0.1 to 0.5 mg/kg IV over 2 to 5 minutes; up to a maximum of 10 mg/dose. May repeat dose every 5 to 10 minutes as needed) or LORAZEPAM (ADULT: 2 to 4 mg IV initially; repeat every 5 to 10 minutes as needed, if seizures persist. CHILD: 0.05 to 0.1 mg/kg IV over 2 to 5 minutes, up to a maximum of 4 mg/dose; may repeat in 5 to 15 minutes as needed, if seizures continue).

1) Consider phenobarbital or propofol if seizures recur after diazepam 30 mg (adults) or 10 mg (children greater than 5 years).
2) Monitor for hypotension, dysrhythmias, respiratory depression, and need for endotracheal intubation. Evaluate for hypoglycemia, electrolyte disturbances, and hypoxia.

C) ACUTE LUNG INJURY: Maintain ventilation and oxygenation and evaluate with frequent arterial blood gases and/or pulse oximetry monitoring. Early use of PEEP and mechanical ventilation may be needed.
D) METHEMOGLOBINEMIA: Determine the methemoglobin concentration and evaluate the patient for clinical effects of methemoglobinemia (ie, dyspnea, headache, fatigue, CNS depression, tachycardia, metabolic acidosis). Treat patients with symptomatic methemoglobinemia with methylene blue (this usually occurs at methemoglobin concentrations above 20% to 30%, but may occur at lower methemoglobin concentrations in patients with anemia, or underlying pulmonary or cardiovascular disorders). Administer oxygen while preparing for methylene blue therapy.
E) METHYLENE BLUE: INITIAL DOSE/ADULT OR CHILD: 1 mg/kg IV over 5 to 30 minutes; a repeat dose of up to 1 mg/kg may be given 1 hour after the first dose if methemoglobin levels remain greater than 30% or if signs and symptoms persist. NOTE: Methylene blue is available as follows: 50 mg/10 mL (5 mg/mL or 0.5% solution) single-dose ampules and 10 mg/1 mL (1% solution) vials. Additional doses may sometimes be required. Improvement is usually noted shortly after administration if diagnosis is correct. Consider other diagnoses or treatment options if no improvement has been observed after several doses. If intravenous access cannot be established, methylene blue may also be given by intraosseous infusion. Methylene blue should not be given by subcutaneous or intrathecal injection. NEONATES: DOSE: 0.3 to 1 mg/kg.
F) Concomitant use of methylene blue with serotonergic drugs, including serotonin reuptake inhibitors (SRIs), selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), norepinephrine-dopamine reuptake inhibitors (NDRIs), triptans, and ergot alkaloids may increase the risk of potentially fatal serotonin syndrome.
G) Pyridoxine may be antidotal. Dose of pyridoxine is 25 mg/kg, 1/3 given IM and 2/3 given IV over 3 hours. Increase the dose by 25 mg/kg every 5 to 10 minutes to a maximum of 300 mg/kg/dose for continuing CNS symptoms (seizures, coma).

0.4.4)

A) DECONTAMINATION: Remove contact lenses and irrigate exposed eyes with copious amounts of room temperature 0.9% saline or water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist after 15 minutes of irrigation, the patient should be seen in a healthcare facility.
B) Patients symptomatic following exposure should be observed in a controlled setting until all signs and symptoms have fully resolved.
C) SEIZURES: Administer a benzodiazepine; DIAZEPAM (ADULT: 5 to 10 mg IV initially; repeat every 5 to 20 minutes as needed. CHILD: 0.1 to 0.5 mg/kg IV over 2 to 5 minutes; up to a maximum of 10 mg/dose. May repeat dose every 5 to 10 minutes as needed) or LORAZEPAM (ADULT: 2 to 4 mg IV initially; repeat every 5 to 10 minutes as needed, if seizures persist. CHILD: 0.05 to 0.1 mg/kg IV over 2 to 5 minutes, up to a maximum of 4 mg/dose; may repeat in 5 to 15 minutes as needed, if seizures continue).

1) Consider phenobarbital or propofol if seizures recur after diazepam 30 mg (adults) or 10 mg (children greater than 5 years).
2) Monitor for hypotension, dysrhythmias, respiratory depression, and need for endotracheal intubation. Evaluate for hypoglycemia, electrolyte disturbances, and hypoxia.

D) ACUTE LUNG INJURY: Maintain ventilation and oxygenation and evaluate with frequent arterial blood gases and/or pulse oximetry monitoring. Early use of PEEP and mechanical ventilation may be needed.
E) METHEMOGLOBINEMIA: Determine the methemoglobin concentration and evaluate the patient for clinical effects of methemoglobinemia (ie, dyspnea, headache, fatigue, CNS depression, tachycardia, metabolic acidosis). Treat patients with symptomatic methemoglobinemia with methylene blue (this usually occurs at methemoglobin concentrations above 20% to 30%, but may occur at lower methemoglobin concentrations in patients with anemia, or underlying pulmonary or cardiovascular disorders). Administer oxygen while preparing for methylene blue therapy.
F) METHYLENE BLUE: INITIAL DOSE/ADULT OR CHILD: 1 mg/kg IV over 5 to 30 minutes; a repeat dose of up to 1 mg/kg may be given 1 hour after the first dose if methemoglobin levels remain greater than 30% or if signs and symptoms persist. NOTE: Methylene blue is available as follows: 50 mg/10 mL (5 mg/mL or 0.5% solution) single-dose ampules and 10 mg/1 mL (1% solution) vials. Additional doses may sometimes be required. Improvement is usually noted shortly after administration if diagnosis is correct. Consider other diagnoses or treatment options if no improvement has been observed after several doses. If intravenous access cannot be established, methylene blue may also be given by intraosseous infusion. Methylene blue should not be given by subcutaneous or intrathecal injection. NEONATES: DOSE: 0.3 to 1 mg/kg.
G) Concomitant use of methylene blue with serotonergic drugs, including serotonin reuptake inhibitors (SRIs), selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), norepinephrine-dopamine reuptake inhibitors (NDRIs), triptans, and ergot alkaloids may increase the risk of potentially fatal serotonin syndrome.
H) Pyridoxine may be antidotal. Dose of pyridoxine is 25 mg/kg, 1/3 given IM and 2/3 given IV over 3 hours. Increase the dose by 25 mg/kg every 5 to 10 minutes to a maximum of 300 mg/kg/dose for continuing CNS symptoms (seizures, coma).

0.4.5)

A) OVERVIEW

1) DECONTAMINATION: Remove contaminated clothing and jewelry and place them in plastic bags. Wash exposed areas with soap and water for 10 to 15 minutes with gentle sponging to avoid skin breakdown. A physician may need to examine the area if irritation or pain persists (Burgess et al, 1999).
2) Treat dermal irritation or burns with standard topical therapy. Patients developing dermal hypersensitivity reactions may require treatment with systemic or topical corticosteroids or antihistamines.
3) SEIZURES: Administer a benzodiazepine; DIAZEPAM (ADULT: 5 to 10 mg IV initially; repeat every 5 to 20 minutes as needed. CHILD: 0.1 to 0.5 mg/kg IV over 2 to 5 minutes; up to a maximum of 10 mg/dose. May repeat dose every 5 to 10 minutes as needed) or LORAZEPAM (ADULT: 2 to 4 mg IV initially; repeat every 5 to 10 minutes as needed, if seizures persist. CHILD: 0.05 to 0.1 mg/kg IV over 2 to 5 minutes, up to a maximum of 4 mg/dose; may repeat in 5 to 15 minutes as needed, if seizures continue).

a) Consider phenobarbital or propofol if seizures recur after diazepam 30 mg (adults) or 10 mg (children greater than 5 years).
b) Monitor for hypotension, dysrhythmias, respiratory depression, and need for endotracheal intubation. Evaluate for hypoglycemia, electrolyte disturbances, and hypoxia.

4) ACUTE LUNG INJURY: Maintain ventilation and oxygenation and evaluate with frequent arterial blood gases and/or pulse oximetry monitoring. Early use of PEEP and mechanical ventilation may be needed.
5) METHEMOGLOBINEMIA: Determine the methemoglobin concentration and evaluate the patient for clinical effects of methemoglobinemia (ie, dyspnea, headache, fatigue, CNS depression, tachycardia, metabolic acidosis). Treat patients with symptomatic methemoglobinemia with methylene blue (this usually occurs at methemoglobin concentrations above 20% to 30%, but may occur at lower methemoglobin concentrations in patients with anemia, or underlying pulmonary or cardiovascular disorders). Administer oxygen while preparing for methylene blue therapy.
6) METHYLENE BLUE: INITIAL DOSE/ADULT OR CHILD: 1 mg/kg IV over 5 to 30 minutes; a repeat dose of up to 1 mg/kg may be given 1 hour after the first dose if methemoglobin levels remain greater than 30% or if signs and symptoms persist. NOTE: Methylene blue is available as follows: 50 mg/10 mL (5 mg/mL or 0.5% solution) single-dose ampules and 10 mg/1 mL (1% solution) vials. Additional doses may sometimes be required. Improvement is usually noted shortly after administration if diagnosis is correct. Consider other diagnoses or treatment options if no improvement has been observed after several doses. If intravenous access cannot be established, methylene blue may also be given by intraosseous infusion. Methylene blue should not be given by subcutaneous or intrathecal injection. NEONATES: DOSE: 0.3 to 1 mg/kg.
7) Concomitant use of methylene blue with serotonergic drugs, including serotonin reuptake inhibitors (SRIs), selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), norepinephrine-dopamine reuptake inhibitors (NDRIs), triptans, and ergot alkaloids may increase the risk of potentially fatal serotonin syndrome.
8) Pyridoxine may be antidotal. Dose of pyridoxine is 25 mg/kg, 1/3 given IM and 2/3 given IV over 3 hours. Increase the dose by 25 mg/kg every 5 to 10 minutes to a maximum of 300 mg/kg/dose for continuing CNS symptoms (seizures, coma).

Range Of Toxicity

A)

B)

Clinical Effects

Hepatic

3.9.1)

A) Fatty degeneration and occasional hepatic necrosis may occur.

3.9.2)

A) LIVER DAMAGE

1) Phenylhydrazine hydrochloride is a hepatotoxin (EPA, 1985). It produces fatty infiltration and/or cellular damage (Clayton & Clayton, 1994).

Genitourinary

3.10.1)

A) Renal damage, possibly secondary to hemolysis, may occur from phenylhydrazine.

3.10.2)

A) TOXIC NEPHROPATHY

1) Hydrazines, including phenylhydrazine, may cause kidney damage directly, or indirectly due to red blood cell hemolysis and renal tubular deposition of RBC breakdown products (Clayton & Clayton, 1994) (Sittig, 1991). Severe tubular necrosis and nephritis have been reported from exposure to hydrazine (Sotaniemi et al, 1971).

Hematologic

3.13.1)

A) Hemolysis, thrombosis, methemoglobinemia, and anemia may occur.

3.13.2)

A) HEMOLYSIS

1) Phenylhydrazine is an effective hemolytic agent, regardless of the route of exposure (Clayton & Clayton, 1994).
2) Pretreatment of rats with silymarin inhibited in vitro hemolysis induced by phenylhydrazine (Valenzuela et al, 1985).

B) HEMOLYTIC ANEMIA

1) Phenylhydrazine hydrochloride can induce hemolytic anemia (EPA, 1985). At least one case has been reported in a human, in connection with chronic use of phenylhydrazine hydrochloride for treatment of polycythemia (Hansen, 1950).
2) In chickens, the hallmark of hemolytic anemia induced by phenylhydrazine hydrochloride was the appearance of Heinz bodies in the cytoplasm (Datta et al, 1990). Heinz bodies were not apparent in a human case of hemolytic anemia induced by phenylhydrazine hydrochloride, however (Hansen, 1950).
3) Erythrophagocytosis by mononuclear cells occurred in the livers of chickens treated with phenylhydrazine hydrochloride (Datta et al, 1989).

C) THROMBOEMBOLUS

1) Phenylhydrazine hydrochloride can cause blood clots (EPA, 1985).

D) METHEMOGLOBINEMIA

1) Phenylhydrazine hydrochloride produced methemoglobinemia in rats and rabbits following a single 24-hour dermal application of 0.01 to 0.5 g/kg (Derelanko et al, 1987).

Dermatologic

3.14.1)

A) Skin irritation has been reported in humans. Necrosis occurred at the site of application in rats and rabbits.

3.14.2)

A) SKIN IRRITATION

1) Phenylhydrazine hydrochloride is irritating to the skin and can cause dermatitis (EPA, 1985).
2) The free base is the most irritating of all the hydrazines (Clayton & Clayton, 1994).

B) SKIN NECROSIS

1) Necrosis was produced at the site of dermal application in rabbits and rats (Derelanko et al, 1987).

Musculoskeletal

3.15.1)

A) Arthralgias have been reported.

3.15.2)

A) JOINT PAIN

1) Arthralgias have been reported (Durant & Harris, 1980).

Endocrine

3.16.1)

A) Hypoglycemia or hyperglycemia may occur with hydrazines, depending on the glycogen reserves in the liver.

3.16.2)

A) HYPOGLYCEMIA

1) Abnormalities in blood sugar measurements have been reported in patients exposed to hydrazine. These measurements may vary according to the amount of glycogen in the liver. If glycogen stores are greater than 5 mg/g, then hyperglycemia (1 to 3 days after ingestion) will proceed to hypoglycemia. If glycogen stores are depleted, only hypoglycemia may be seen (Clark et al, 1968).

Reproductive

3.20.1)

A) At the time of this review, no data were available to assess the potential effects of exposure to this agent during pregnancy or lactation.

3.20.2)

A) CNS EFFECTS

1) Behavioral effects have been observed in the offspring of rats administered phenylhydrazine hydrochloride (RTECS , 1991).

3.20.3)

A) LACK OF INFORMATION

1) At the time of this review, no data were available to assess the potential effects of exposure to this agent during pregnancy or lactation.

Carcinogenicity

3.21.1)

A) IARC Carcinogenicity Ratings for CAS59-88-1 (International Agency for Research on Cancer (IARC), 2016; International Agency for Research on Cancer, 2015; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2010; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2010a; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2008; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2007; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2006; IARC, 2004):

1) Not Listed

3.21.2)

A) Phenylhydrazine is a suspected human carcinogen.

3.21.3)

A) CARCINOMA

1) Phenylhydrazine hydrochloride has been listed as an equivocal tumorigenic agent to a neoplastic agent in mouse studies by RTECS criteria, depending on dose and route of administration. Tumors were demonstrated in the lungs, thorax, and blood (including Hodgkin's disease) (RTECS , 1996).
2) Phenylhydrazine given at 0.01 percent in the drinking water induced blood vessel tumors (adenomas and adenocarcinomas of the lungs and angiosarcomas of the blood vessels) (Toth & Shimizu, 1976).
3) Lung tumors were more malignant in mice treated orally with phenylhydrazine hydrochloride for 59 weeks; their incidence was not increased, however (Santilli, 1965).
4) No epidemiological studies on the possible carcinogenicity of phenylhydrazine hydrochloride in humans were found at the time of this review. Phenylhydrazine is a SUSPECTED HUMAN CARCINOGEN, however (ACGIH, 1991).

Summary Of Exposure

A)

B)

Vital Signs

3.3.1)

A) Fever may occur.

3.3.2)

A) IRRITATION: Inhalation of phenylhydrazine hydrochloride dust produces coughing (EPA, 1985).
B) DYSPNEA: Dyspnea may occur after breathing the dust (EPA, 1985).
C) CYANOSIS: Anoxia and cyanosis can occur with hydrazines (Sittig, 1985). A single dermal application of 0.5 g/kg phenylhydrazine hydrochloride produced cyanosis in rabbits (Derelanko et al, 1987).

3.3.3)

A) Fever has occurred in dogs given methyl hydrazine (Jacobson et al, 1955).

Heent

3.4.1)

A) Phenylhydrazine hydrochloride is an eye irritant. Facial edema, conjunctivitis, salivation, and headache have been reported with hydrazine exposure.

3.4.2)

A) HEADACHE may occur (EPA, 1985).
B) Facial edema may occur with exposure to hydrazines (Durant & Harris, 1980).

3.4.3)

A) CONJUNCTIVITIS - Phenylhydrazine hydrochloride dust is irritating to the eyes (EPA, 198). Severe facial edema (Durant & Harris, 1980), conjunctivitis (Sotaniemi et al, 1971), and salivation in both humans and experimental animals (McGrath et al, 1953) (Clayton & Clayton, 1994) have been reported from exposure to hydrazines.

1) Eye inflammation, chorioretinitis, and retinal degeneration occurred in rabbits after injection of phenylhydrazine hydrochloride directly into the vitreous humor (Grant, 1993).

3.4.6)

A) IRRITATION: Sore throat may occur (EPA, 1985).
B) SALIVATION may occur in both humans and experimental animals.

Cardiovascular

3.5.1)

A) Hypotension may occur.

3.5.2)

A) HYPOTENSIVE EPISODE

1) Hypotension induced by hydrazines is believed to be caused by both direct and indirect effects on smooth muscle (Murtha & Wills, 1953).

Respiratory

3.6.1)

A) Respiratory irritation, dyspnea, or cyanosis can occur from breathing phenylhydrazine hydrochloride dust. Acute exposure to low concentrations of hydrazines may cause delayed death (days) and produce bronchial mucous destruction and pulmonary edema.

3.6.2)

A) IRRITATION SYMPTOM

1) Phenylhydrazine hydrochloride is a respiratory tract irritant (EPA, 1985).

B) ACUTE LUNG INJURY

1) Pulmonary edema has occurred in several human cases of inhalation of hydrazine vapor. Pulmonary edema was successfully treated with pyridoxine (ACGIH, 1986).

C) CYANOSIS

1) Cyanosis and anoxia can occur (Clayton & Clayton, 1994).

Neurologic

3.7.1)

A) CNS stimulation, excitability, tremors, convulsions, and coma have occurred.

3.7.2)

A) DEPRESSIVE DISORDER

1) Signs of CNS depression, such as dizziness, occur at lower-level exposures (Hathaway et al, 1991; OHM/TADS , 1996).

B) TREMOR

1) Excitability, tremors and other signs of CNS stimulation may occur (CHRIS , 1996; EPA, 1985).

C) SEIZURE

1) Convulsions can occur with hydrazines (Jenney & Pfeiffer, 1958) (Clayton & Clayton, 1994; Hathaway et al, 1991; CHRIS , 1996). Tonic-clonic convulsions have occurred in experimental animals following a latent period (HSDB , 1996).

D) COMA

1) Coma was reported 14 hours after exposure in a patient with a thermal burn secondary to a hydrazine explosion. Coma persisted for 60 hours, until 4 hours after initiation of pyridoxine therapy (Kirklin et al, 1976).

E) ATAXIA

1) Persistent ataxia and inability to write were evident in a patient who ingested hydrazine (Reid, 1965).

F) PARESTHESIA

1) Paresthesias and limb weakness, diagnosed as sensory polyneuropathy with axonal degeneration, were noted in a patient who ingested hydrazine. The condition resolved spontaneously over the next 6 months. The polyneuropathy was attributed primarily to the pyridoxine therapy (Harati & Niakan, 1986).

Gastrointestinal

3.8.1)

A) Nausea and anorexia are common.

3.8.2)

A) NAUSEA

1) Nausea and anorexia may occur (EPA, 1985).

B) LOSS OF APPETITE

1) Anorexia may occur (Clayton & Clayton, 1994; McGrath et al, 1952).

Genotoxicity

A)

Laboratory Monitoring

Monitoring Parameters Levels

4.1.1)

A) If respiratory tract irritation or respiratory depression is evident, monitor arterial blood gases, chest x-ray, and pulmonary function tests.
B) A number of chemicals produce abnormalities of the hematopoietic system, liver, and kidneys. Monitoring complete blood count, urinalysis, and liver and kidney function tests is suggested for patients with significant exposure.
C) Monitor methemoglobin levels and blood sugar.

4.1.2)

A) BLOOD/SERUM CHEMISTRY

1) A number of chemicals produce abnormalities of the hematopoietic system, liver, and kidneys. Monitoring complete blood count and liver and kidney function tests is suggested for patients with significant exposure.
2) Monitor blood sugar.
3) This agent may cause nephrotoxicity. Monitor renal function tests and urinalysis in patients with significant exposure.

B) HEMATOLOGIC

1) Because of the presence of hemoglobin-like pigments which cannot carry oxygen, the hemoglobin level underestimated the extent of hemolytic anemia induced by phenylhydrazine hydrochloride in dogs (Taylor et al, 1973).
2) The hydrazines can induce methemoglobinemia, which may not be apparent for several days. Monitor methemoglobin levels.

4.1.4)

A) OTHER

1) MONITORING

a) If respiratory tract irritation or respiratory depression is evident, monitor arterial blood gases, chest x-ray, and pulmonary function tests.

Treatment

Life Support

A)

Monitoring

A)

B)

C)

Oral Exposure

6.5.2)

A) EMESIS/NOT RECOMMENDED

1) Do NOT induce emesis.

B) ACTIVATED CHARCOAL

1) CHARCOAL ADMINISTRATION

a) Consider administration of activated charcoal after a potentially toxic ingestion (Chyka et al, 2005). Administer charcoal as an aqueous slurry; most effective when administered within one hour of ingestion.

2) CHARCOAL DOSE

a) Use a minimum of 240 milliliters of water per 30 grams charcoal (FDA, 1985). Optimum dose not established; usual dose is 25 to 100 grams in adults and adolescents; 25 to 50 grams in children aged 1 to 12 years (or 0.5 to 1 gram/kilogram body weight) ; and 0.5 to 1 gram/kilogram in infants up to 1 year old (Chyka et al, 2005).

1) Routine use of a cathartic with activated charcoal is NOT recommended as there is no evidence that cathartics reduce drug absorption and cathartics are known to cause adverse effects such as nausea, vomiting, abdominal cramps, electrolyte imbalances and occasionally hypotension (None Listed, 2004).

b) ADVERSE EFFECTS/CONTRAINDICATIONS

1) Complications: emesis, aspiration (Chyka et al, 2005). Aspiration may be complicated by acute respiratory failure, ARDS, bronchiolitis obliterans or chronic lung disease (Golej et al, 2001; Graff et al, 2002; Pollack et al, 1981; Harris & Filandrinos, 1993; Elliot et al, 1989; Rau et al, 1988; Golej et al, 2001; Graff et al, 2002). Refer to the ACTIVATED CHARCOAL/TREATMENT management for further information.
2) Contraindications: unprotected airway (increases risk/severity of aspiration) , nonfunctioning gastrointestinal tract, uncontrolled vomiting, and ingestion of most hydrocarbons (Chyka et al, 2005).

C) GASTRIC LAVAGE

1) INDICATIONS: Consider gastric lavage with a large-bore orogastric tube (ADULT: 36 to 40 French or 30 English gauge tube {external diameter 12 to 13.3 mm}; CHILD: 24 to 28 French {diameter 7.8 to 9.3 mm}) after a potentially life threatening ingestion if it can be performed soon after ingestion (generally within 60 minutes).

a) Consider lavage more than 60 minutes after ingestion of sustained-release formulations and substances known to form bezoars or concretions.

2) PRECAUTIONS:

a) SEIZURE CONTROL: Is mandatory prior to gastric lavage.
b) AIRWAY PROTECTION: Place patients in the head down left lateral decubitus position, with suction available. Patients with depressed mental status should be intubated with a cuffed endotracheal tube prior to lavage.

3) LAVAGE FLUID:

a) Use small aliquots of liquid. Lavage with 200 to 300 milliliters warm tap water (preferably 38 degrees Celsius) or saline per wash (in older children or adults) and 10 milliliters/kilogram body weight of normal saline in young children(Vale et al, 2004) and repeat until lavage return is clear.
b) The volume of lavage return should approximate amount of fluid given to avoid fluid-electrolyte imbalance.
c) CAUTION: Water should be avoided in young children because of the risk of electrolyte imbalance and water intoxication. Warm fluids avoid the risk of hypothermia in very young children and the elderly.

4) COMPLICATIONS:

a) Complications of gastric lavage have included: aspiration pneumonia, hypoxia, hypercapnia, mechanical injury to the throat, esophagus, or stomach, fluid and electrolyte imbalance (Vale, 1997). Combative patients may be at greater risk for complications (Caravati et al, 2001).
b) Gastric lavage can cause significant morbidity; it should NOT be performed routinely in all poisoned patients (Vale, 1997).

5) CONTRAINDICATIONS:

a) Loss of airway protective reflexes or decreased level of consciousness if patient is not intubated, following ingestion of corrosive substances, hydrocarbons (high aspiration potential), patients at risk of hemorrhage or gastrointestinal perforation, or trivial or non-toxic ingestion.

6.5.3)

A) SEIZURE

1) SUMMARY

a) Attempt initial control with a benzodiazepine (eg, diazepam, lorazepam). If seizures persist or recur, administer phenobarbital or propofol.
b) Monitor for respiratory depression, hypotension, and dysrhythmias. Endotracheal intubation should be performed in patients with persistent seizures.
c) Evaluate for hypoxia, electrolyte disturbances, and hypoglycemia (or, if immediate bedside glucose testing is not available, treat with intravenous dextrose).

2) DIAZEPAM

a) ADULT DOSE: Initially 5 to 10 mg IV, OR 0.15 mg/kg IV up to 10 mg per dose up to a rate of 5 mg/minute; may be repeated every 5 to 20 minutes as needed (Brophy et al, 2012; Prod Info diazepam IM, IV injection, 2008; Manno, 2003).
b) PEDIATRIC DOSE: 0.1 to 0.5 mg/kg IV over 2 to 5 minutes; up to a maximum of 10 mg/dose. May repeat dose every 5 to 10 minutes as needed (Loddenkemper & Goodkin, 2011; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008).
c) Monitor for hypotension, respiratory depression, and the need for endotracheal intubation. Consider a second agent if seizures persist or recur after repeated doses of diazepam .

3) NO INTRAVENOUS ACCESS

a) DIAZEPAM may be given rectally or intramuscularly (Manno, 2003). RECTAL DOSE: CHILD: Greater than 12 years: 0.2 mg/kg; 6 to 11 years: 0.3 mg/kg; 2 to 5 years: 0.5 mg/kg (Brophy et al, 2012).
b) MIDAZOLAM has been used intramuscularly and intranasally, particularly in children when intravenous access has not been established. ADULT DOSE: 0.2 mg/kg IM, up to a maximum dose of 10 mg (Brophy et al, 2012). PEDIATRIC DOSE: INTRAMUSCULAR: 0.2 mg/kg IM, up to a maximum dose of 7 mg (Chamberlain et al, 1997) OR 10 mg IM (weight greater than 40 kg); 5 mg IM (weight 13 to 40 kg); INTRANASAL: 0.2 to 0.5 mg/kg up to a maximum of 10 mg/dose (Loddenkemper & Goodkin, 2011; Brophy et al, 2012). BUCCAL midazolam, 10 mg, has been used in adolescents and older children (5-years-old or more) to control seizures when intravenous access was not established (Scott et al, 1999).

4) LORAZEPAM

a) MAXIMUM RATE: The rate of intravenous administration of lorazepam should not exceed 2 mg/min (Brophy et al, 2012; Prod Info lorazepam IM, IV injection, 2008).
b) ADULT DOSE: 2 to 4 mg IV initially; repeat every 5 to 10 minutes as needed, if seizures persist (Manno, 2003; Brophy et al, 2012).
c) PEDIATRIC DOSE: 0.05 to 0.1 mg/kg IV over 2 to 5 minutes, up to a maximum of 4 mg/dose; may repeat in 5 to 15 minutes as needed, if seizures continue (Brophy et al, 2012; Loddenkemper & Goodkin, 2011; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008; Sreenath et al, 2009; Chin et al, 2008).

5) PHENOBARBITAL

a) ADULT LOADING DOSE: 20 mg/kg IV at an infusion rate of 50 to 100 mg/minute IV. An additional 5 to 10 mg/kg dose may be given 10 minutes after loading infusion if seizures persist or recur (Brophy et al, 2012).
b) Patients receiving high doses will require endotracheal intubation and may require vasopressor support (Brophy et al, 2012).
c) PEDIATRIC LOADING DOSE: 20 mg/kg may be given as single or divided application (2 mg/kg/minute in children weighing less than 40 kg up to 100 mg/min in children weighing greater than 40 kg). A plasma concentration of about 20 mg/L will be achieved by this dose (Loddenkemper & Goodkin, 2011).
d) REPEAT PEDIATRIC DOSE: Repeat doses of 5 to 20 mg/kg may be given every 15 to 20 minutes if seizures persist, with cardiorespiratory monitoring (Loddenkemper & Goodkin, 2011).
e) MONITOR: For hypotension, respiratory depression, and the need for endotracheal intubation (Loddenkemper & Goodkin, 2011; Manno, 2003).
f) SERUM CONCENTRATION MONITORING: Monitor serum concentrations over the next 12 to 24 hours. Therapeutic serum concentrations of phenobarbital range from 10 to 40 mcg/mL, although the optimal plasma concentration for some individuals may vary outside this range (Hvidberg & Dam, 1976; Choonara & Rane, 1990; AMA Department of Drugs, 1992).

6) OTHER AGENTS

a) If seizures persist after phenobarbital, propofol or pentobarbital infusion, or neuromuscular paralysis with general anesthesia (isoflurane) and continuous EEG monitoring should be considered (Manno, 2003). Other anticonvulsants can be considered (eg, valproate sodium, levetiracetam, lacosamide, topiramate) if seizures persist or recur; however, there is very little data regarding their use in toxin induced seizures, controlled trials are not available to define the optimal dosage ranges for these agents in status epilepticus (Brophy et al, 2012):

1) VALPROATE SODIUM: ADULT DOSE: An initial dose of 20 to 40 mg/kg IV, at a rate of 3 to 6 mg/kg/minute; may give an additional dose of 20 mg/kg 10 minutes after loading infusion. PEDIATRIC DOSE: 1.5 to 3 mg/kg/minute (Brophy et al, 2012).
2) LEVETIRACETAM: ADULT DOSE: 1000 to 3000 mg IV, at a rate of 2 to 5 mg/kg/min IV. PEDIATRIC DOSE: 20 to 60 mg/kg IV (Brophy et al, 2012; Loddenkemper & Goodkin, 2011).
3) LACOSAMIDE: ADULT DOSE: 200 to 400 mg IV; 200 mg IV over 15 minutes (Brophy et al, 2012). PEDIATRIC DOSE: In one study, median starting doses of 1.3 mg/kg/day and maintenance doses of 4.7 mg/kg/day were used in children 8 years and older (Loddenkemper & Goodkin, 2011).
4) TOPIRAMATE: ADULT DOSE: 200 to 400 mg nasogastric/orally OR 300 to 1600 mg/day orally divided in 2 to 4 times daily (Brophy et al, 2012).

B) IRRITATION SYMPTOM

1) Respiratory tract irritation, if severe, can progress to noncardiogenic pulmonary edema which may be delayed in onset up to 24 to 72 hours after exposure in some cases.
2) There are no controlled studies indicating that early administration of corticosteroids can prevent the development of noncardiogenic pulmonary edema in patients with inhalation exposure to respiratory irritant substances, and long-term use may cause adverse effects (Boysen & Modell, 1989).

a) However, based on anecdotal experience, some clinicians do recommend early administration of corticosteroids (such as methylprednisolone 1 gram intravenously as a single dose) in an attempt to prevent the later development of pulmonary edema.

1) Anecdotal experience with dimethyl sulfate inhalation showed possible benefit of methylprednisolone in the TREATMENT of noncardiogenic pulmonary edema (Ip et al, 1989).

3) Anecdotal experience also indicated that systemic corticosteroids may have possible efficacy in the TREATMENT of drug-induced noncardiogenic pulmonary edema (Zitnik & Cooper, 1990; Stentoft, 1990; Chudnofsky & Otten, 1989) or noncardiogenic pulmonary edema developing after cardiopulmonary bypass (Maggart & Stewart, 1987).
4) It is not clear from the published literature that administration of systemic corticosteroids early following inhalation exposure to respiratory irritant substances can PREVENT the development of noncardiogenic pulmonary edema. The decision to administer or withhold corticosteroids in this setting must currently be made on clinical grounds.

C) ACUTE LUNG INJURY

1) ONSET: Onset of acute lung injury after toxic exposure may be delayed up to 24 to 72 hours after exposure in some cases.
2) NON-PHARMACOLOGIC TREATMENT: The treatment of acute lung injury is primarily supportive (Cataletto, 2012). Maintain adequate ventilation and oxygenation with frequent monitoring of arterial blood gases and/or pulse oximetry. If a high FIO2 is required to maintain adequate oxygenation, mechanical ventilation and positive-end-expiratory pressure (PEEP) may be required; ventilation with small tidal volumes (6 mL/kg) is preferred if ARDS develops (Haas, 2011; Stolbach & Hoffman, 2011).

a) To minimize barotrauma and other complications, use the lowest amount of PEEP possible while maintaining adequate oxygenation. Use of smaller tidal volumes (6 mL/kg) and lower plateau pressures (30 cm water or less) has been associated with decreased mortality and more rapid weaning from mechanical ventilation in patients with ARDS (Brower et al, 2000). More treatment information may be obtained from ARDS Clinical Network website, NIH NHLBI ARDS Clinical Network Mechanical Ventilation Protocol Summary, http://www.ardsnet.org/node/77791 (NHLBI ARDS Network, 2008)

3) FLUIDS: Crystalloid solutions must be administered judiciously. Pulmonary artery monitoring may help. In general the pulmonary artery wedge pressure should be kept relatively low while still maintaining adequate cardiac output, blood pressure and urine output (Stolbach & Hoffman, 2011).
4) ANTIBIOTICS: Indicated only when there is evidence of infection (Artigas et al, 1998).
5) EXPERIMENTAL THERAPY: Partial liquid ventilation has shown promise in preliminary studies (Kollef & Schuster, 1995).
6) CALFACTANT: In a multicenter, randomized, blinded trial, endotracheal instillation of 2 doses of 80 mL/m(2) calfactant (35 mg/mL of phospholipid suspension in saline) in infants, children, and adolescents with acute lung injury resulted in acute improvement in oxygenation and lower mortality; however, no significant decrease in the course of respiratory failure measured by duration of ventilator therapy, intensive care unit, or hospital stay was noted. Adverse effects (transient hypoxia and hypotension) were more frequent in calfactant patients, but these effects were mild and did not require withdrawal from the study (Wilson et al, 2005).
7) However, in a multicenter, randomized, controlled, and masked trial, endotracheal instillation of up to 3 doses of calfactant (30 mg) in adults only with acute lung injury/ARDS due to direct lung injury was not associated with improved oxygenation and longer term benefits compared to the placebo group. It was also associated with significant increases in hypoxia and hypotension (Willson et al, 2015).

D) METHEMOGLOBINEMIA

1) SUMMARY

a) Determine the methemoglobin concentration and evaluate the patient for clinical effects of methemoglobinemia (ie, dyspnea, headache, fatigue, CNS depression, tachycardia, metabolic acidosis). Treat patients with symptomatic methemoglobinemia with methylene blue (this usually occurs at methemoglobin concentrations above 20% to 30%, but may occur at lower methemoglobin concentrations in patients with anemia, or underlying pulmonary or cardiovascular disorders). Administer oxygen while preparing for methylene blue therapy.

2) METHYLENE BLUE

a) INITIAL DOSE/ADULT OR CHILD: 1 mg/kg IV over 5 to 30 minutes; a repeat dose of up to 1 mg/kg may be given 1 hour after the first dose if methemoglobin levels remain greater than 30% or if signs and symptoms persist. NOTE: Methylene blue is available as follows: 50 mg/10 mL (5 mg/mL or 0.5% solution) single-dose ampules (Prod Info PROVAYBLUE(TM) intravenous injection, 2016) and 10 mg/1 mL (1% solution) vials (Prod Info methylene blue 1% intravenous injection, 2011). REPEAT DOSES: Additional doses may be required, especially for substances with prolonged absorption, slow elimination, or those that form metabolites that produce methemoglobin. NOTE: Large doses of methylene blue may cause methemoglobinemia or hemolysis (Howland, 2006). Improvement is usually noted shortly after administration if diagnosis is correct. Consider other diagnoses or treatment options if no improvement has been observed after several doses. If intravenous access cannot be established, methylene blue may also be given by intraosseous infusion. Methylene blue should not be given by subcutaneous or intrathecal injection (Prod Info methylene blue 1% intravenous injection, 2011; Herman et al, 1999). NEONATES: DOSE: 0.3 to 1 mg/kg (Hjelt et al, 1995).
b) CONTRAINDICATIONS: G-6-PD deficiency (methylene blue may cause hemolysis), known hypersensitivity to methylene blue, methemoglobin reductase deficiency (Shepherd & Keyes, 2004)
c) FAILURE: Failure of methylene blue therapy suggests: inadequate dose of methylene blue, inadequate decontamination, NADPH dependent methemoglobin reductase deficiency, hemoglobin M disease, sulfhemoglobinemia, or G-6-PD deficiency. Methylene blue is reduced by methemoglobin reductase and nicotinamide adenosine dinucleotide phosphate (NADPH) to leukomethylene blue. This in turn reduces methemoglobin. Red blood cells of patients with G-6-PD deficiency do not produce enough NADPH to convert methylene blue to leukomethylene blue (do Nascimento et al, 2008).
d) DRUG INTERACTION: Concomitant use of methylene blue with serotonergic drugs, including serotonin reuptake inhibitors (SRIs), selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), norepinephrine-dopamine reuptake inhibitors (NDRIs), triptans, and ergot alkaloids may increase the risk of potentially fatal serotonin syndrome (U.S. Food and Drug Administration, 2011; Stanford et al, 2010; Prod Info methylene blue 1% IV injection, 2011).

3) TOLUIDINE BLUE OR TOLONIUM CHLORIDE (GERMANY)

a) DOSE: 2 to 4 mg/kg intravenously over 5 minutes. Dose may be repeated in 30 minutes (Nemec, 2011; Lindenmann et al, 2006; Kiese et al, 1972).
b) SIDE EFFECTS: Hypotension with rapid intravenous administration. Vomiting, diarrhea, excessive sweating, hypotension, dysrhythmias, hemolysis, agranulocytosis and acute renal insufficiency after overdose (Dunipace et al, 1992; Hix & Wilson, 1987; Winek et al, 1969; Teunis et al, 1970; Marquez & Todd, 1959).
c) CONTRAINDICATIONS: G-6-PD deficiency; may cause hemolysis.

E) HYPOGLYCEMIA

1) Monitor blood sugar. Elevated blood sugar early in the clinical course may be evidence of glycogenolysis and could be followed by sudden, severe hypoglycemia requiring immediate glucose treatment. Severe hypoglycemia may appear without the preceding hyperglycemia.

F) PYRIDOXINE

1) Pyridoxine may be antidotal for coma and seizures (Kirklin et al, 1976), as well as for the milder CNS effects of hydrazine poisoning (Frierson, 1965).
2) Doses suggested in case reports include pyridoxine 25 mg/kg parenterally. In one case, this produced rapid reversal of coma in 4 hours in a patient who had been comatose for over 60 hours (Kirklin et al, 1976).
3) Inhalation of a mixture of hydrazine and unsymmetrical dimethylhydrazine produced one case of mild symptoms (twitching, nausea, headache, and dyspnea). These symptoms, but not pulmonary edema, were eliminated by 200 mg of pyridoxine IV and 400 mg IM (Frierson, 1965).
4) Experimental animal studies indicated pyridoxine to be effective against unsymmetrical dimethylhydrazine, but not hydrazine. When used to treat experimental animals exposed to hydrazine-unsymmetrical dimethylhydrazine mixtures, pyridoxine was less effective (Azar et al, 1970). Predictions of its usefulness vary by species (Clark et al, 1968).
5) CAUTIONS

a) Pyridoxine doses of 0.2 to 5 g/day for 2 to 40 months have caused ataxia and severe sensory nervous system dysfunction (Schaumburg, 1983) (Parry & Bredesen, 1985) (Berger & Schaumburg, 1984)(Dalton, 1985). The maximum nontoxic pyridoxine dose is unknown.
b) Case reports have described only the use of single parenteral doses for the treatment of hydrazine toxicity. One study reports the use of 10 g of pyridoxine IV in a 24-year-old man who ingested "a mouthful" of hydrazine.

1) One week later the patient developed paresthesias of his hands and feet and mild distal limb weakness. Three weeks post-injection he had diminished pinprick, vibration, touch and position senses in his distal arms to the wrists and distal legs to the ankles. The peripheral neuropathy spontaneously cleared over the next 6 months. Although the neuropathy may have been due to the hydrazine, the symptoms are also similar to those of pyridoxine neurotoxicity (Harati & Niakan, 1986).

G) MONITORING OF PATIENT

1) Monitor liver function tests as hydrazines are hepatotoxic.

Inhalation Exposure

6.7.1)

A) Move patient from the toxic environment to fresh air. Monitor for respiratory distress. If cough or difficulty in breathing develops, evaluate for hypoxia, respiratory tract irritation, bronchitis, or pneumonitis.
B) OBSERVATION: Carefully observe patients with inhalation exposure for the development of any systemic signs or symptoms and administer symptomatic treatment as necessary.
C) INITIAL TREATMENT: Administer 100% humidified supplemental oxygen, perform endotracheal intubation and provide assisted ventilation as required. Administer inhaled beta-2 adrenergic agonists, if bronchospasm develops. Consider systemic corticosteroids in patients with significant bronchospasm (National Heart,Lung,and Blood Institute, 2007). Exposed skin and eyes should be flushed with copious amounts of water.

6.7.2)

A) SEIZURE

1) SUMMARY

a) Attempt initial control with a benzodiazepine (eg, diazepam, lorazepam). If seizures persist or recur, administer phenobarbital or propofol.
b) Monitor for respiratory depression, hypotension, and dysrhythmias. Endotracheal intubation should be performed in patients with persistent seizures.
c) Evaluate for hypoxia, electrolyte disturbances, and hypoglycemia (or, if immediate bedside glucose testing is not available, treat with intravenous dextrose).

2) DIAZEPAM

a) ADULT DOSE: Initially 5 to 10 mg IV, OR 0.15 mg/kg IV up to 10 mg per dose up to a rate of 5 mg/minute; may be repeated every 5 to 20 minutes as needed (Brophy et al, 2012; Prod Info diazepam IM, IV injection, 2008; Manno, 2003).
b) PEDIATRIC DOSE: 0.1 to 0.5 mg/kg IV over 2 to 5 minutes; up to a maximum of 10 mg/dose. May repeat dose every 5 to 10 minutes as needed (Loddenkemper & Goodkin, 2011; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008).
c) Monitor for hypotension, respiratory depression, and the need for endotracheal intubation. Consider a second agent if seizures persist or recur after repeated doses of diazepam .

3) NO INTRAVENOUS ACCESS

a) DIAZEPAM may be given rectally or intramuscularly (Manno, 2003). RECTAL DOSE: CHILD: Greater than 12 years: 0.2 mg/kg; 6 to 11 years: 0.3 mg/kg; 2 to 5 years: 0.5 mg/kg (Brophy et al, 2012).
b) MIDAZOLAM has been used intramuscularly and intranasally, particularly in children when intravenous access has not been established. ADULT DOSE: 0.2 mg/kg IM, up to a maximum dose of 10 mg (Brophy et al, 2012). PEDIATRIC DOSE: INTRAMUSCULAR: 0.2 mg/kg IM, up to a maximum dose of 7 mg (Chamberlain et al, 1997) OR 10 mg IM (weight greater than 40 kg); 5 mg IM (weight 13 to 40 kg); INTRANASAL: 0.2 to 0.5 mg/kg up to a maximum of 10 mg/dose (Loddenkemper & Goodkin, 2011; Brophy et al, 2012). BUCCAL midazolam, 10 mg, has been used in adolescents and older children (5-years-old or more) to control seizures when intravenous access was not established (Scott et al, 1999).

4) LORAZEPAM

a) MAXIMUM RATE: The rate of intravenous administration of lorazepam should not exceed 2 mg/min (Brophy et al, 2012; Prod Info lorazepam IM, IV injection, 2008).
b) ADULT DOSE: 2 to 4 mg IV initially; repeat every 5 to 10 minutes as needed, if seizures persist (Manno, 2003; Brophy et al, 2012).
c) PEDIATRIC DOSE: 0.05 to 0.1 mg/kg IV over 2 to 5 minutes, up to a maximum of 4 mg/dose; may repeat in 5 to 15 minutes as needed, if seizures continue (Brophy et al, 2012; Loddenkemper & Goodkin, 2011; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008; Sreenath et al, 2009; Chin et al, 2008).

5) PHENOBARBITAL

a) ADULT LOADING DOSE: 20 mg/kg IV at an infusion rate of 50 to 100 mg/minute IV. An additional 5 to 10 mg/kg dose may be given 10 minutes after loading infusion if seizures persist or recur (Brophy et al, 2012).
b) Patients receiving high doses will require endotracheal intubation and may require vasopressor support (Brophy et al, 2012).
c) PEDIATRIC LOADING DOSE: 20 mg/kg may be given as single or divided application (2 mg/kg/minute in children weighing less than 40 kg up to 100 mg/min in children weighing greater than 40 kg). A plasma concentration of about 20 mg/L will be achieved by this dose (Loddenkemper & Goodkin, 2011).
d) REPEAT PEDIATRIC DOSE: Repeat doses of 5 to 20 mg/kg may be given every 15 to 20 minutes if seizures persist, with cardiorespiratory monitoring (Loddenkemper & Goodkin, 2011).
e) MONITOR: For hypotension, respiratory depression, and the need for endotracheal intubation (Loddenkemper & Goodkin, 2011; Manno, 2003).
f) SERUM CONCENTRATION MONITORING: Monitor serum concentrations over the next 12 to 24 hours. Therapeutic serum concentrations of phenobarbital range from 10 to 40 mcg/mL, although the optimal plasma concentration for some individuals may vary outside this range (Hvidberg & Dam, 1976; Choonara & Rane, 1990; AMA Department of Drugs, 1992).

6) OTHER AGENTS

a) If seizures persist after phenobarbital, propofol or pentobarbital infusion, or neuromuscular paralysis with general anesthesia (isoflurane) and continuous EEG monitoring should be considered (Manno, 2003). Other anticonvulsants can be considered (eg, valproate sodium, levetiracetam, lacosamide, topiramate) if seizures persist or recur; however, there is very little data regarding their use in toxin induced seizures, controlled trials are not available to define the optimal dosage ranges for these agents in status epilepticus (Brophy et al, 2012):

1) VALPROATE SODIUM: ADULT DOSE: An initial dose of 20 to 40 mg/kg IV, at a rate of 3 to 6 mg/kg/minute; may give an additional dose of 20 mg/kg 10 minutes after loading infusion. PEDIATRIC DOSE: 1.5 to 3 mg/kg/minute (Brophy et al, 2012).
2) LEVETIRACETAM: ADULT DOSE: 1000 to 3000 mg IV, at a rate of 2 to 5 mg/kg/min IV. PEDIATRIC DOSE: 20 to 60 mg/kg IV (Brophy et al, 2012; Loddenkemper & Goodkin, 2011).
3) LACOSAMIDE: ADULT DOSE: 200 to 400 mg IV; 200 mg IV over 15 minutes (Brophy et al, 2012). PEDIATRIC DOSE: In one study, median starting doses of 1.3 mg/kg/day and maintenance doses of 4.7 mg/kg/day were used in children 8 years and older (Loddenkemper & Goodkin, 2011).
4) TOPIRAMATE: ADULT DOSE: 200 to 400 mg nasogastric/orally OR 300 to 1600 mg/day orally divided in 2 to 4 times daily (Brophy et al, 2012).

B) IRRITATION SYMPTOM

1) Respiratory tract irritation, if severe, can progress to noncardiogenic pulmonary edema which may be delayed in onset up to 24 to 72 hours after exposure in some cases.
2) There are no controlled studies indicating that early administration of corticosteroids can prevent the development of noncardiogenic pulmonary edema in patients with inhalation exposure to respiratory irritant substances, and long-term use may cause adverse effects (Boysen & Modell, 1989).

a) However, based on anecdotal experience, some clinicians do recommend early administration of corticosteroids (such as methylprednisolone 1 gram intravenously as a single dose) in an attempt to prevent the later development of pulmonary edema.

1) Anecdotal experience with dimethyl sulfate inhalation showed possible benefit of methylprednisolone in the TREATMENT of noncardiogenic pulmonary edema (Ip et al, 1989).

3) Anecdotal experience also indicated that systemic corticosteroids may have possible efficacy in the TREATMENT of drug-induced noncardiogenic pulmonary edema (Zitnik & Cooper, 1990; Stentoft, 1990; Chudnofsky & Otten, 1989) or noncardiogenic pulmonary edema developing after cardiopulmonary bypass (Maggart & Stewart, 1987).
4) It is not clear from the published literature that administration of systemic corticosteroids early following inhalation exposure to respiratory irritant substances can PREVENT the development of noncardiogenic pulmonary edema. The decision to administer or withhold corticosteroids in this setting must currently be made on clinical grounds.

C) ACUTE LUNG INJURY

1) ONSET: Onset of acute lung injury after toxic exposure may be delayed up to 24 to 72 hours after exposure in some cases.
2) NON-PHARMACOLOGIC TREATMENT: The treatment of acute lung injury is primarily supportive (Cataletto, 2012). Maintain adequate ventilation and oxygenation with frequent monitoring of arterial blood gases and/or pulse oximetry. If a high FIO2 is required to maintain adequate oxygenation, mechanical ventilation and positive-end-expiratory pressure (PEEP) may be required; ventilation with small tidal volumes (6 mL/kg) is preferred if ARDS develops (Haas, 2011; Stolbach & Hoffman, 2011).

a) To minimize barotrauma and other complications, use the lowest amount of PEEP possible while maintaining adequate oxygenation. Use of smaller tidal volumes (6 mL/kg) and lower plateau pressures (30 cm water or less) has been associated with decreased mortality and more rapid weaning from mechanical ventilation in patients with ARDS (Brower et al, 2000). More treatment information may be obtained from ARDS Clinical Network website, NIH NHLBI ARDS Clinical Network Mechanical Ventilation Protocol Summary, http://www.ardsnet.org/node/77791 (NHLBI ARDS Network, 2008)

3) FLUIDS: Crystalloid solutions must be administered judiciously. Pulmonary artery monitoring may help. In general the pulmonary artery wedge pressure should be kept relatively low while still maintaining adequate cardiac output, blood pressure and urine output (Stolbach & Hoffman, 2011).
4) ANTIBIOTICS: Indicated only when there is evidence of infection (Artigas et al, 1998).
5) EXPERIMENTAL THERAPY: Partial liquid ventilation has shown promise in preliminary studies (Kollef & Schuster, 1995).
6) CALFACTANT: In a multicenter, randomized, blinded trial, endotracheal instillation of 2 doses of 80 mL/m(2) calfactant (35 mg/mL of phospholipid suspension in saline) in infants, children, and adolescents with acute lung injury resulted in acute improvement in oxygenation and lower mortality; however, no significant decrease in the course of respiratory failure measured by duration of ventilator therapy, intensive care unit, or hospital stay was noted. Adverse effects (transient hypoxia and hypotension) were more frequent in calfactant patients, but these effects were mild and did not require withdrawal from the study (Wilson et al, 2005).
7) However, in a multicenter, randomized, controlled, and masked trial, endotracheal instillation of up to 3 doses of calfactant (30 mg) in adults only with acute lung injury/ARDS due to direct lung injury was not associated with improved oxygenation and longer term benefits compared to the placebo group. It was also associated with significant increases in hypoxia and hypotension (Willson et al, 2015).

D) METHEMOGLOBINEMIA

1) SUMMARY

a) Determine the methemoglobin concentration and evaluate the patient for clinical effects of methemoglobinemia (ie, dyspnea, headache, fatigue, CNS depression, tachycardia, metabolic acidosis). Treat patients with symptomatic methemoglobinemia with methylene blue (this usually occurs at methemoglobin concentrations above 20% to 30%, but may occur at lower methemoglobin concentrations in patients with anemia, or underlying pulmonary or cardiovascular disorders). Administer oxygen while preparing for methylene blue therapy.

2) METHYLENE BLUE

a) INITIAL DOSE/ADULT OR CHILD: 1 mg/kg IV over 5 to 30 minutes; a repeat dose of up to 1 mg/kg may be given 1 hour after the first dose if methemoglobin levels remain greater than 30% or if signs and symptoms persist. NOTE: Methylene blue is available as follows: 50 mg/10 mL (5 mg/mL or 0.5% solution) single-dose ampules (Prod Info PROVAYBLUE(TM) intravenous injection, 2016) and 10 mg/1 mL (1% solution) vials (Prod Info methylene blue 1% intravenous injection, 2011). REPEAT DOSES: Additional doses may be required, especially for substances with prolonged absorption, slow elimination, or those that form metabolites that produce methemoglobin. NOTE: Large doses of methylene blue may cause methemoglobinemia or hemolysis (Howland, 2006). Improvement is usually noted shortly after administration if diagnosis is correct. Consider other diagnoses or treatment options if no improvement has been observed after several doses. If intravenous access cannot be established, methylene blue may also be given by intraosseous infusion. Methylene blue should not be given by subcutaneous or intrathecal injection (Prod Info methylene blue 1% intravenous injection, 2011; Herman et al, 1999). NEONATES: DOSE: 0.3 to 1 mg/kg (Hjelt et al, 1995).
b) CONTRAINDICATIONS: G-6-PD deficiency (methylene blue may cause hemolysis), known hypersensitivity to methylene blue, methemoglobin reductase deficiency (Shepherd & Keyes, 2004)
c) FAILURE: Failure of methylene blue therapy suggests: inadequate dose of methylene blue, inadequate decontamination, NADPH dependent methemoglobin reductase deficiency, hemoglobin M disease, sulfhemoglobinemia, or G-6-PD deficiency. Methylene blue is reduced by methemoglobin reductase and nicotinamide adenosine dinucleotide phosphate (NADPH) to leukomethylene blue. This in turn reduces methemoglobin. Red blood cells of patients with G-6-PD deficiency do not produce enough NADPH to convert methylene blue to leukomethylene blue (do Nascimento et al, 2008).
d) DRUG INTERACTION: Concomitant use of methylene blue with serotonergic drugs, including serotonin reuptake inhibitors (SRIs), selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), norepinephrine-dopamine reuptake inhibitors (NDRIs), triptans, and ergot alkaloids may increase the risk of potentially fatal serotonin syndrome (U.S. Food and Drug Administration, 2011; Stanford et al, 2010; Prod Info methylene blue 1% IV injection, 2011).

3) TOLUIDINE BLUE OR TOLONIUM CHLORIDE (GERMANY)

a) DOSE: 2 to 4 mg/kg intravenously over 5 minutes. Dose may be repeated in 30 minutes (Nemec, 2011; Lindenmann et al, 2006; Kiese et al, 1972).
b) SIDE EFFECTS: Hypotension with rapid intravenous administration. Vomiting, diarrhea, excessive sweating, hypotension, dysrhythmias, hemolysis, agranulocytosis and acute renal insufficiency after overdose (Dunipace et al, 1992; Hix & Wilson, 1987; Winek et al, 1969; Teunis et al, 1970; Marquez & Todd, 1959).
c) CONTRAINDICATIONS: G-6-PD deficiency; may cause hemolysis.

E) HYPOGLYCEMIA

1) Monitor blood sugar. Elevated blood sugar early in the clinical course may be evidence of glycogenolysis and could be followed by sudden, severe hypoglycemia requiring immediate glucose treatment. Severe hypoglycemia may appear without preceding hyperglycemia.

F) PYRIDOXINE

1) Pyridoxine may be antidotal for coma and seizures (Kirklin et al, 1976), as well as for the milder CNS effects of hydrazine poisoning (Frierson, 1965).
2) Doses suggested in case reports include: pyridoxine 25 mg/kg parenterally. In one case, this produced rapid reversal of coma in 4 hours in a patient who had been comatose for over 60 hours (Kirklin et al, 1976).
3) Inhalation of a mixture of hydrazine and unsymmetrical dimethylhydrazine produced one case of mild symptoms (twitching, nausea, headache, and dyspnea). These symptoms, but not pulmonary edema, were eliminated by 200 milligrams of pyridoxine intravenously and 400 milligrams intramuscularly (Frierson, 1965).
4) Experimental animal studies indicated pyridoxine to be effective against unsymmetrical dimethylhydrazine, but not hydrazine. When used to treat experimental animals exposed to hydrazine-unsymmetrical dimethylhydrazine mixtures, pyridoxine was less effective (Azar et al, 1970). Predictions of its usefulness vary by species (Clark et al, 1968).
5) CAUTIONS

a) Pyridoxine doses of 0.2 to 5 grams per day for 2 to 40 months have caused ataxia and severe sensory nervous system dysfunction (Schaumburg, 1983) (Parry & Bredesen, 1985) (Berger & Schaumburg, 1984) (Dalton, 1985). The maximum nontoxic pyridoxine dose is unknown.
b) Case reports have described only the use of single parenteral doses for the treatment of hydrazine toxicity. One study reports the use of 10 g of pyridoxine IV in a 24-year-old man who ingested "a mouthful" of hydrazine.

1) One week later the patient developed paresthesias of his hands and feet and mild distal limb weakness. Three weeks post-injection he had diminished pinprick, vibration, touch, and position senses in his distal arms to the wrists and distal legs to the ankles.
2) The peripheral neuropathy spontaneously cleared over the next 6 months. Although the neuropathy may have been due to the hydrazine, the symptoms are also similar to those of pyridoxine neurotoxicity (Harati & Niakan, 1986).

G) MONITORING OF PATIENT

1) Monitor liver function tests as hydrazines are hepatotoxic.

H) Treatment should include recommendations listed in the ORAL EXPOSURE section when appropriate.

Eye Exposure

6.8.1)

A) EYE IRRIGATION, ROUTINE: Remove contact lenses and irrigate exposed eyes with copious amounts of room temperature 0.9% saline or water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist after 15 minutes of irrigation, an ophthalmologic examination should be performed (Peate, 2007; Naradzay & Barish, 2006).

6.8.2)

A) SEIZURE

1) SUMMARY

a) Attempt initial control with a benzodiazepine (eg, diazepam, lorazepam). If seizures persist or recur, administer phenobarbital or propofol.
b) Monitor for respiratory depression, hypotension, and dysrhythmias. Endotracheal intubation should be performed in patients with persistent seizures.
c) Evaluate for hypoxia, electrolyte disturbances, and hypoglycemia (or, if immediate bedside glucose testing is not available, treat with intravenous dextrose).

2) DIAZEPAM

a) ADULT DOSE: Initially 5 to 10 mg IV, OR 0.15 mg/kg IV up to 10 mg per dose up to a rate of 5 mg/minute; may be repeated every 5 to 20 minutes as needed (Brophy et al, 2012; Prod Info diazepam IM, IV injection, 2008; Manno, 2003).
b) PEDIATRIC DOSE: 0.1 to 0.5 mg/kg IV over 2 to 5 minutes; up to a maximum of 10 mg/dose. May repeat dose every 5 to 10 minutes as needed (Loddenkemper & Goodkin, 2011; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008).
c) Monitor for hypotension, respiratory depression, and the need for endotracheal intubation. Consider a second agent if seizures persist or recur after repeated doses of diazepam .

3) NO INTRAVENOUS ACCESS

a) DIAZEPAM may be given rectally or intramuscularly (Manno, 2003). RECTAL DOSE: CHILD: Greater than 12 years: 0.2 mg/kg; 6 to 11 years: 0.3 mg/kg; 2 to 5 years: 0.5 mg/kg (Brophy et al, 2012).
b) MIDAZOLAM has been used intramuscularly and intranasally, particularly in children when intravenous access has not been established. ADULT DOSE: 0.2 mg/kg IM, up to a maximum dose of 10 mg (Brophy et al, 2012). PEDIATRIC DOSE: INTRAMUSCULAR: 0.2 mg/kg IM, up to a maximum dose of 7 mg (Chamberlain et al, 1997) OR 10 mg IM (weight greater than 40 kg); 5 mg IM (weight 13 to 40 kg); INTRANASAL: 0.2 to 0.5 mg/kg up to a maximum of 10 mg/dose (Loddenkemper & Goodkin, 2011; Brophy et al, 2012). BUCCAL midazolam, 10 mg, has been used in adolescents and older children (5-years-old or more) to control seizures when intravenous access was not established (Scott et al, 1999).

4) LORAZEPAM

a) MAXIMUM RATE: The rate of intravenous administration of lorazepam should not exceed 2 mg/min (Brophy et al, 2012; Prod Info lorazepam IM, IV injection, 2008).
b) ADULT DOSE: 2 to 4 mg IV initially; repeat every 5 to 10 minutes as needed, if seizures persist (Manno, 2003; Brophy et al, 2012).
c) PEDIATRIC DOSE: 0.05 to 0.1 mg/kg IV over 2 to 5 minutes, up to a maximum of 4 mg/dose; may repeat in 5 to 15 minutes as needed, if seizures continue (Brophy et al, 2012; Loddenkemper & Goodkin, 2011; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008; Sreenath et al, 2009; Chin et al, 2008).

5) PHENOBARBITAL

a) ADULT LOADING DOSE: 20 mg/kg IV at an infusion rate of 50 to 100 mg/minute IV. An additional 5 to 10 mg/kg dose may be given 10 minutes after loading infusion if seizures persist or recur (Brophy et al, 2012).
b) Patients receiving high doses will require endotracheal intubation and may require vasopressor support (Brophy et al, 2012).
c) PEDIATRIC LOADING DOSE: 20 mg/kg may be given as single or divided application (2 mg/kg/minute in children weighing less than 40 kg up to 100 mg/min in children weighing greater than 40 kg). A plasma concentration of about 20 mg/L will be achieved by this dose (Loddenkemper & Goodkin, 2011).
d) REPEAT PEDIATRIC DOSE: Repeat doses of 5 to 20 mg/kg may be given every 15 to 20 minutes if seizures persist, with cardiorespiratory monitoring (Loddenkemper & Goodkin, 2011).
e) MONITOR: For hypotension, respiratory depression, and the need for endotracheal intubation (Loddenkemper & Goodkin, 2011; Manno, 2003).
f) SERUM CONCENTRATION MONITORING: Monitor serum concentrations over the next 12 to 24 hours. Therapeutic serum concentrations of phenobarbital range from 10 to 40 mcg/mL, although the optimal plasma concentration for some individuals may vary outside this range (Hvidberg & Dam, 1976; Choonara & Rane, 1990; AMA Department of Drugs, 1992).

6) OTHER AGENTS

a) If seizures persist after phenobarbital, propofol or pentobarbital infusion, or neuromuscular paralysis with general anesthesia (isoflurane) and continuous EEG monitoring should be considered (Manno, 2003). Other anticonvulsants can be considered (eg, valproate sodium, levetiracetam, lacosamide, topiramate) if seizures persist or recur; however, there is very little data regarding their use in toxin induced seizures, controlled trials are not available to define the optimal dosage ranges for these agents in status epilepticus (Brophy et al, 2012):

1) VALPROATE SODIUM: ADULT DOSE: An initial dose of 20 to 40 mg/kg IV, at a rate of 3 to 6 mg/kg/minute; may give an additional dose of 20 mg/kg 10 minutes after loading infusion. PEDIATRIC DOSE: 1.5 to 3 mg/kg/minute (Brophy et al, 2012).
2) LEVETIRACETAM: ADULT DOSE: 1000 to 3000 mg IV, at a rate of 2 to 5 mg/kg/min IV. PEDIATRIC DOSE: 20 to 60 mg/kg IV (Brophy et al, 2012; Loddenkemper & Goodkin, 2011).
3) LACOSAMIDE: ADULT DOSE: 200 to 400 mg IV; 200 mg IV over 15 minutes (Brophy et al, 2012). PEDIATRIC DOSE: In one study, median starting doses of 1.3 mg/kg/day and maintenance doses of 4.7 mg/kg/day were used in children 8 years and older (Loddenkemper & Goodkin, 2011).
4) TOPIRAMATE: ADULT DOSE: 200 to 400 mg nasogastric/orally OR 300 to 1600 mg/day orally divided in 2 to 4 times daily (Brophy et al, 2012).

B) IRRITATION SYMPTOM

1) Respiratory tract irritation, if severe, can progress to noncardiogenic pulmonary edema which may be delayed in onset up to 24 to 72 hours after exposure in some cases.
2) There are no controlled studies indicating that early administration of corticosteroids can prevent the development of noncardiogenic pulmonary edema in patients with inhalation exposure to respiratory irritant substances, and long-term use may cause adverse effects (Boysen & Modell, 1989).

a) However, based on anecdotal experience, some clinicians do recommend early administration of corticosteroids (such as methylprednisolone 1 gram intravenously as a single dose) in an attempt to prevent the later development of pulmonary edema.

1) Anecdotal experience with dimethyl sulfate inhalation showed possible benefit of methylprednisolone in the TREATMENT of noncardiogenic pulmonary edema (Ip et al, 1989).

3) Anecdotal experience also indicated that systemic corticosteroids may have possible efficacy in the TREATMENT of drug-induced noncardiogenic pulmonary edema (Zitnik & Cooper, 1990; Stentoft, 1990; Chudnofsky & Otten, 1989) or noncardiogenic pulmonary edema developing after cardiopulmonary bypass (Maggart & Stewart, 1987).
4) It is not clear from the published literature that administration of systemic corticosteroids early following inhalation exposure to respiratory irritant substances can PREVENT the development of noncardiogenic pulmonary edema. The decision to administer or withhold corticosteroids in this setting must currently be made on clinical grounds.

C) ACUTE LUNG INJURY

1) ONSET: Onset of acute lung injury after toxic exposure may be delayed up to 24 to 72 hours after exposure in some cases.
2) NON-PHARMACOLOGIC TREATMENT: The treatment of acute lung injury is primarily supportive (Cataletto, 2012). Maintain adequate ventilation and oxygenation with frequent monitoring of arterial blood gases and/or pulse oximetry. If a high FIO2 is required to maintain adequate oxygenation, mechanical ventilation and positive-end-expiratory pressure (PEEP) may be required; ventilation with small tidal volumes (6 mL/kg) is preferred if ARDS develops (Haas, 2011; Stolbach & Hoffman, 2011).

a) To minimize barotrauma and other complications, use the lowest amount of PEEP possible while maintaining adequate oxygenation. Use of smaller tidal volumes (6 mL/kg) and lower plateau pressures (30 cm water or less) has been associated with decreased mortality and more rapid weaning from mechanical ventilation in patients with ARDS (Brower et al, 2000). More treatment information may be obtained from ARDS Clinical Network website, NIH NHLBI ARDS Clinical Network Mechanical Ventilation Protocol Summary, http://www.ardsnet.org/node/77791 (NHLBI ARDS Network, 2008)

3) FLUIDS: Crystalloid solutions must be administered judiciously. Pulmonary artery monitoring may help. In general the pulmonary artery wedge pressure should be kept relatively low while still maintaining adequate cardiac output, blood pressure and urine output (Stolbach & Hoffman, 2011).
4) ANTIBIOTICS: Indicated only when there is evidence of infection (Artigas et al, 1998).
5) EXPERIMENTAL THERAPY: Partial liquid ventilation has shown promise in preliminary studies (Kollef & Schuster, 1995).
6) CALFACTANT: In a multicenter, randomized, blinded trial, endotracheal instillation of 2 doses of 80 mL/m(2) calfactant (35 mg/mL of phospholipid suspension in saline) in infants, children, and adolescents with acute lung injury resulted in acute improvement in oxygenation and lower mortality; however, no significant decrease in the course of respiratory failure measured by duration of ventilator therapy, intensive care unit, or hospital stay was noted. Adverse effects (transient hypoxia and hypotension) were more frequent in calfactant patients, but these effects were mild and did not require withdrawal from the study (Wilson et al, 2005).
7) However, in a multicenter, randomized, controlled, and masked trial, endotracheal instillation of up to 3 doses of calfactant (30 mg) in adults only with acute lung injury/ARDS due to direct lung injury was not associated with improved oxygenation and longer term benefits compared to the placebo group. It was also associated with significant increases in hypoxia and hypotension (Willson et al, 2015).

D) METHEMOGLOBINEMIA

1) SUMMARY

a) Determine the methemoglobin concentration and evaluate the patient for clinical effects of methemoglobinemia (ie, dyspnea, headache, fatigue, CNS depression, tachycardia, metabolic acidosis). Treat patients with symptomatic methemoglobinemia with methylene blue (this usually occurs at methemoglobin concentrations above 20% to 30%, but may occur at lower methemoglobin concentrations in patients with anemia, or underlying pulmonary or cardiovascular disorders). Administer oxygen while preparing for methylene blue therapy.

2) METHYLENE BLUE

a) INITIAL DOSE/ADULT OR CHILD: 1 mg/kg IV over 5 to 30 minutes; a repeat dose of up to 1 mg/kg may be given 1 hour after the first dose if methemoglobin levels remain greater than 30% or if signs and symptoms persist. NOTE: Methylene blue is available as follows: 50 mg/10 mL (5 mg/mL or 0.5% solution) single-dose ampules (Prod Info PROVAYBLUE(TM) intravenous injection, 2016) and 10 mg/1 mL (1% solution) vials (Prod Info methylene blue 1% intravenous injection, 2011). REPEAT DOSES: Additional doses may be required, especially for substances with prolonged absorption, slow elimination, or those that form metabolites that produce methemoglobin. NOTE: Large doses of methylene blue may cause methemoglobinemia or hemolysis (Howland, 2006). Improvement is usually noted shortly after administration if diagnosis is correct. Consider other diagnoses or treatment options if no improvement has been observed after several doses. If intravenous access cannot be established, methylene blue may also be given by intraosseous infusion. Methylene blue should not be given by subcutaneous or intrathecal injection (Prod Info methylene blue 1% intravenous injection, 2011; Herman et al, 1999). NEONATES: DOSE: 0.3 to 1 mg/kg (Hjelt et al, 1995).
b) CONTRAINDICATIONS: G-6-PD deficiency (methylene blue may cause hemolysis), known hypersensitivity to methylene blue, methemoglobin reductase deficiency (Shepherd & Keyes, 2004)
c) FAILURE: Failure of methylene blue therapy suggests: inadequate dose of methylene blue, inadequate decontamination, NADPH dependent methemoglobin reductase deficiency, hemoglobin M disease, sulfhemoglobinemia, or G-6-PD deficiency. Methylene blue is reduced by methemoglobin reductase and nicotinamide adenosine dinucleotide phosphate (NADPH) to leukomethylene blue. This in turn reduces methemoglobin. Red blood cells of patients with G-6-PD deficiency do not produce enough NADPH to convert methylene blue to leukomethylene blue (do Nascimento et al, 2008).
d) DRUG INTERACTION: Concomitant use of methylene blue with serotonergic drugs, including serotonin reuptake inhibitors (SRIs), selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), norepinephrine-dopamine reuptake inhibitors (NDRIs), triptans, and ergot alkaloids may increase the risk of potentially fatal serotonin syndrome (U.S. Food and Drug Administration, 2011; Stanford et al, 2010; Prod Info methylene blue 1% IV injection, 2011).

3) TOLUIDINE BLUE OR TOLONIUM CHLORIDE (GERMANY)

a) DOSE: 2 to 4 mg/kg intravenously over 5 minutes. Dose may be repeated in 30 minutes (Nemec, 2011; Lindenmann et al, 2006; Kiese et al, 1972).
b) SIDE EFFECTS: Hypotension with rapid intravenous administration. Vomiting, diarrhea, excessive sweating, hypotension, dysrhythmias, hemolysis, agranulocytosis and acute renal insufficiency after overdose (Dunipace et al, 1992; Hix & Wilson, 1987; Winek et al, 1969; Teunis et al, 1970; Marquez & Todd, 1959).
c) CONTRAINDICATIONS: G-6-PD deficiency; may cause hemolysis.

E) HYPOGLYCEMIA

1) Monitor blood sugar. Elevated blood sugar early in the clinical course may be evidence of glycogenolysis and could be followed by sudden, severe hypoglycemia requiring immediate glucose treatment. Severe hypoglycemia may appear without preceding hyperglycemia.

F) PYRIDOXINE

1) Pyridoxine may be antidotal for coma and seizures (Kirklin et al, 1976), as well as for the milder CNS effects of hydrazine poisoning (Frierson, 1965).
2) Doses suggested in case reports include pyridoxine 25 mg/kg parenterally. In one case, this produced rapid reversal of coma in 4 hours in a patient who had been comatose for over 60 hours (Kirklin et al, 1976).
3) Inhalation of a mixture of hydrazine and unsymmetrical dimethylhydrazine produced one case of mild symptoms (twitching, nausea, headache, and dyspnea). These symptoms, but not pulmonary edema, were eliminated by 200 milligrams of pyridoxine intravenously and 400 milligrams intramuscularly (Frierson, 1965).
4) Experimental animal studies indicated pyridoxine to be effective against unsymmetrical dimethylhydrazine, but not hydrazine. When used to treat experimental animals exposed to hydrazine-unsymmetrical dimethylhydrazine mixtures, pyridoxine was less effective (Azar et al, 1970). Predictions of its usefulness vary by species (Clark et al, 1968).
5) CAUTIONS

a) Pyridoxine doses of 0.2 to 5 grams per day for 2 to 40 months have caused ataxia and severe sensory nervous system dysfunction (Schaumburg, 1983) (Parry & Bredesen, 1985) (Berger & Schaumburg, 1984) (Dalton, 1985). The maximum nontoxic pyridoxine dose is unknown.
b) Case reports have described only the use of single parenteral doses in treatment for the hydrazine toxicity. One study reports the use of 10 g of pyridoxine IV in a 24-year-old man who ingested "a mouthful" of hydrazine.

1) One week later the patient developed paresthesias of his hands and feet and mild distal limb weakness. Three weeks post-injection he had diminished pinprick, vibration, touch and position senses in his distal arms to the wrists and distal legs to the ankles.
2) The peripheral neuropathy spontaneously cleared over the next 6 months. Although the neuropathy may have been due to the hydrazine, the symptoms are also similar to those of pyridoxine neurotoxicity (Harati & Niakan, 1986).

G) MONITORING OF PATIENT

1) Monitor liver function tests as hydrazines are hepatotoxic.

H) Treatment should include recommendations listed in the ORAL EXPOSURE section when appropriate.

Dermal Exposure

6.9.1)

A) DERMAL DECONTAMINATION

1) DECONTAMINATION: Remove contaminated clothing and wash exposed area thoroughly with soap and water for 10 to 15 minutes. A physician may need to examine the area if irritation or pain persists (Burgess et al, 1999).

6.9.2)

A) BURN

1) APPLICATION

a) These recommendations apply to patients with MINOR chemical burns (FIRST DEGREE; SECOND DEGREE: less than 15% body surface area in adults; less than 10% body surface area in children; THIRD DEGREE: less than 2% body surface area). Consultation with a clinician experienced in burn therapy or a burn unit should be obtained if larger area or more severe burns are present. Neutralizing agents should NOT be used.

2) DEBRIDEMENT

a) After initial flushing with large volumes of water to remove any residual chemical material, clean wounds with a mild disinfectant soap and water.
b) DEVITALIZED SKIN: Loose, nonviable tissue should be removed by gentle cleansing with surgical soap or formal skin debridement (Moylan, 1980; Haynes, 1981). Intravenous analgesia may be required (Roberts, 1988).
c) BLISTERS: Removal and debridement of closed blisters is controversial. Current consensus is that intact blisters prevent pain and dehydration, promote healing, and allow motion; therefore, blisters should be left intact until they rupture spontaneously or healing is well underway, unless they are extremely large or inhibit motion (Roberts, 1988; Carvajal & Stewart, 1987).

3) TREATMENT

a) TOPICAL ANTIBIOTICS: Prophylactic topical antibiotic therapy with silver sulfadiazine is recommended for all burns except superficial partial thickness (first-degree) burns (Roberts, 1988). For first-degree burns bacitracin may be used, but effectiveness is not documented (Roberts, 1988).
b) SYSTEMIC ANTIBIOTICS: Systemic antibiotics are generally not indicated unless infection is present or the burn involves the hands, feet, or perineum.
c) WOUND DRESSING:

1) Depending on the site and area, the burn may be treated open (face, ears, or perineum) or covered with sterile nonstick porous gauze. The gauze dressing should be fluffy and thick enough to absorb all drainage.
2) Alternatively, a petrolatum fine-mesh gauze dressing may be used alone on partial-thickness burns.

d) DRESSING CHANGES:

1) Daily dressing changes are indicated if a burn cream is used; changes every 3 to 4 days are adequate with a dry dressing.
2) If dressing changes are to be done at home, the patient or caregiver should be instructed in proper techniques and given sufficient dressings and other necessary supplies.

e) Analgesics such as acetaminophen with codeine may be used for pain relief if needed.

4) TETANUS PROPHYLAXIS

a) The patient's tetanus immunization status should be determined. Tetanus toxoid 0.5 milliliter intramuscularly or other indicated tetanus prophylaxis should be administered if required.

B) SEIZURE

1) SUMMARY

a) Attempt initial control with a benzodiazepine (eg, diazepam, lorazepam). If seizures persist or recur, administer phenobarbital or propofol.
b) Monitor for respiratory depression, hypotension, and dysrhythmias. Endotracheal intubation should be performed in patients with persistent seizures.
c) Evaluate for hypoxia, electrolyte disturbances, and hypoglycemia (or, if immediate bedside glucose testing is not available, treat with intravenous dextrose).

2) DIAZEPAM

a) ADULT DOSE: Initially 5 to 10 mg IV, OR 0.15 mg/kg IV up to 10 mg per dose up to a rate of 5 mg/minute; may be repeated every 5 to 20 minutes as needed (Brophy et al, 2012; Prod Info diazepam IM, IV injection, 2008; Manno, 2003).
b) PEDIATRIC DOSE: 0.1 to 0.5 mg/kg IV over 2 to 5 minutes; up to a maximum of 10 mg/dose. May repeat dose every 5 to 10 minutes as needed (Loddenkemper & Goodkin, 2011; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008).
c) Monitor for hypotension, respiratory depression, and the need for endotracheal intubation. Consider a second agent if seizures persist or recur after repeated doses of diazepam .

3) NO INTRAVENOUS ACCESS

a) DIAZEPAM may be given rectally or intramuscularly (Manno, 2003). RECTAL DOSE: CHILD: Greater than 12 years: 0.2 mg/kg; 6 to 11 years: 0.3 mg/kg; 2 to 5 years: 0.5 mg/kg (Brophy et al, 2012).
b) MIDAZOLAM has been used intramuscularly and intranasally, particularly in children when intravenous access has not been established. ADULT DOSE: 0.2 mg/kg IM, up to a maximum dose of 10 mg (Brophy et al, 2012). PEDIATRIC DOSE: INTRAMUSCULAR: 0.2 mg/kg IM, up to a maximum dose of 7 mg (Chamberlain et al, 1997) OR 10 mg IM (weight greater than 40 kg); 5 mg IM (weight 13 to 40 kg); INTRANASAL: 0.2 to 0.5 mg/kg up to a maximum of 10 mg/dose (Loddenkemper & Goodkin, 2011; Brophy et al, 2012). BUCCAL midazolam, 10 mg, has been used in adolescents and older children (5-years-old or more) to control seizures when intravenous access was not established (Scott et al, 1999).

4) LORAZEPAM

a) MAXIMUM RATE: The rate of intravenous administration of lorazepam should not exceed 2 mg/min (Brophy et al, 2012; Prod Info lorazepam IM, IV injection, 2008).
b) ADULT DOSE: 2 to 4 mg IV initially; repeat every 5 to 10 minutes as needed, if seizures persist (Manno, 2003; Brophy et al, 2012).
c) PEDIATRIC DOSE: 0.05 to 0.1 mg/kg IV over 2 to 5 minutes, up to a maximum of 4 mg/dose; may repeat in 5 to 15 minutes as needed, if seizures continue (Brophy et al, 2012; Loddenkemper & Goodkin, 2011; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008; Sreenath et al, 2009; Chin et al, 2008).

5) PHENOBARBITAL

a) ADULT LOADING DOSE: 20 mg/kg IV at an infusion rate of 50 to 100 mg/minute IV. An additional 5 to 10 mg/kg dose may be given 10 minutes after loading infusion if seizures persist or recur (Brophy et al, 2012).
b) Patients receiving high doses will require endotracheal intubation and may require vasopressor support (Brophy et al, 2012).
c) PEDIATRIC LOADING DOSE: 20 mg/kg may be given as single or divided application (2 mg/kg/minute in children weighing less than 40 kg up to 100 mg/min in children weighing greater than 40 kg). A plasma concentration of about 20 mg/L will be achieved by this dose (Loddenkemper & Goodkin, 2011).
d) REPEAT PEDIATRIC DOSE: Repeat doses of 5 to 20 mg/kg may be given every 15 to 20 minutes if seizures persist, with cardiorespiratory monitoring (Loddenkemper & Goodkin, 2011).
e) MONITOR: For hypotension, respiratory depression, and the need for endotracheal intubation (Loddenkemper & Goodkin, 2011; Manno, 2003).
f) SERUM CONCENTRATION MONITORING: Monitor serum concentrations over the next 12 to 24 hours. Therapeutic serum concentrations of phenobarbital range from 10 to 40 mcg/mL, although the optimal plasma concentration for some individuals may vary outside this range (Hvidberg & Dam, 1976; Choonara & Rane, 1990; AMA Department of Drugs, 1992).

6) OTHER AGENTS

a) If seizures persist after phenobarbital, propofol or pentobarbital infusion, or neuromuscular paralysis with general anesthesia (isoflurane) and continuous EEG monitoring should be considered (Manno, 2003). Other anticonvulsants can be considered (eg, valproate sodium, levetiracetam, lacosamide, topiramate) if seizures persist or recur; however, there is very little data regarding their use in toxin induced seizures, controlled trials are not available to define the optimal dosage ranges for these agents in status epilepticus (Brophy et al, 2012):

1) VALPROATE SODIUM: ADULT DOSE: An initial dose of 20 to 40 mg/kg IV, at a rate of 3 to 6 mg/kg/minute; may give an additional dose of 20 mg/kg 10 minutes after loading infusion. PEDIATRIC DOSE: 1.5 to 3 mg/kg/minute (Brophy et al, 2012).
2) LEVETIRACETAM: ADULT DOSE: 1000 to 3000 mg IV, at a rate of 2 to 5 mg/kg/min IV. PEDIATRIC DOSE: 20 to 60 mg/kg IV (Brophy et al, 2012; Loddenkemper & Goodkin, 2011).
3) LACOSAMIDE: ADULT DOSE: 200 to 400 mg IV; 200 mg IV over 15 minutes (Brophy et al, 2012). PEDIATRIC DOSE: In one study, median starting doses of 1.3 mg/kg/day and maintenance doses of 4.7 mg/kg/day were used in children 8 years and older (Loddenkemper & Goodkin, 2011).
4) TOPIRAMATE: ADULT DOSE: 200 to 400 mg nasogastric/orally OR 300 to 1600 mg/day orally divided in 2 to 4 times daily (Brophy et al, 2012).

C) IRRITATION SYMPTOM

1) Respiratory tract irritation, if severe, can progress to noncardiogenic pulmonary edema which may be delayed in onset up to 24 to 72 hours after exposure in some cases.
2) There are no controlled studies indicating that early administration of corticosteroids can prevent the development of noncardiogenic pulmonary edema in patients with inhalation exposure to respiratory irritant substances, and long-term use may cause adverse effects (Boysen & Modell, 1989).

a) However, based on anecdotal experience, some clinicians do recommend early administration of corticosteroids (such as methylprednisolone 1 gram intravenously as a single dose) in an attempt to prevent the later development of pulmonary edema.

1) Anecdotal experience with dimethyl sulfate inhalation showed possible benefit of methylprednisolone in the TREATMENT of noncardiogenic pulmonary edema (Ip et al, 1989).

3) Anecdotal experience also indicated that systemic corticosteroids may have possible efficacy in the TREATMENT of drug-induced noncardiogenic pulmonary edema (Zitnik & Cooper, 1990; Stentoft, 1990; Chudnofsky & Otten, 1989) or noncardiogenic pulmonary edema developing after cardiopulmonary bypass (Maggart & Stewart, 1987).
4) It is not clear from the published literature that administration of systemic corticosteroids early following inhalation exposure to respiratory irritant substances can PREVENT the development of noncardiogenic pulmonary edema. The decision to administer or withhold corticosteroids in this setting must currently be made on clinical grounds.

D) ACUTE LUNG INJURY

1) ONSET: Onset of acute lung injury after toxic exposure may be delayed up to 24 to 72 hours after exposure in some cases.
2) NON-PHARMACOLOGIC TREATMENT: The treatment of acute lung injury is primarily supportive (Cataletto, 2012). Maintain adequate ventilation and oxygenation with frequent monitoring of arterial blood gases and/or pulse oximetry. If a high FIO2 is required to maintain adequate oxygenation, mechanical ventilation and positive-end-expiratory pressure (PEEP) may be required; ventilation with small tidal volumes (6 mL/kg) is preferred if ARDS develops (Haas, 2011; Stolbach & Hoffman, 2011).

a) To minimize barotrauma and other complications, use the lowest amount of PEEP possible while maintaining adequate oxygenation. Use of smaller tidal volumes (6 mL/kg) and lower plateau pressures (30 cm water or less) has been associated with decreased mortality and more rapid weaning from mechanical ventilation in patients with ARDS (Brower et al, 2000). More treatment information may be obtained from ARDS Clinical Network website, NIH NHLBI ARDS Clinical Network Mechanical Ventilation Protocol Summary, http://www.ardsnet.org/node/77791 (NHLBI ARDS Network, 2008)

3) FLUIDS: Crystalloid solutions must be administered judiciously. Pulmonary artery monitoring may help. In general the pulmonary artery wedge pressure should be kept relatively low while still maintaining adequate cardiac output, blood pressure and urine output (Stolbach & Hoffman, 2011).
4) ANTIBIOTICS: Indicated only when there is evidence of infection (Artigas et al, 1998).
5) EXPERIMENTAL THERAPY: Partial liquid ventilation has shown promise in preliminary studies (Kollef & Schuster, 1995).
6) CALFACTANT: In a multicenter, randomized, blinded trial, endotracheal instillation of 2 doses of 80 mL/m(2) calfactant (35 mg/mL of phospholipid suspension in saline) in infants, children, and adolescents with acute lung injury resulted in acute improvement in oxygenation and lower mortality; however, no significant decrease in the course of respiratory failure measured by duration of ventilator therapy, intensive care unit, or hospital stay was noted. Adverse effects (transient hypoxia and hypotension) were more frequent in calfactant patients, but these effects were mild and did not require withdrawal from the study (Wilson et al, 2005).
7) However, in a multicenter, randomized, controlled, and masked trial, endotracheal instillation of up to 3 doses of calfactant (30 mg) in adults only with acute lung injury/ARDS due to direct lung injury was not associated with improved oxygenation and longer term benefits compared to the placebo group. It was also associated with significant increases in hypoxia and hypotension (Willson et al, 2015).

E) METHEMOGLOBINEMIA

1) SUMMARY

a) Determine the methemoglobin concentration and evaluate the patient for clinical effects of methemoglobinemia (ie, dyspnea, headache, fatigue, CNS depression, tachycardia, metabolic acidosis). Treat patients with symptomatic methemoglobinemia with methylene blue (this usually occurs at methemoglobin concentrations above 20% to 30%, but may occur at lower methemoglobin concentrations in patients with anemia, or underlying pulmonary or cardiovascular disorders). Administer oxygen while preparing for methylene blue therapy.

2) METHYLENE BLUE

a) INITIAL DOSE/ADULT OR CHILD: 1 mg/kg IV over 5 to 30 minutes; a repeat dose of up to 1 mg/kg may be given 1 hour after the first dose if methemoglobin levels remain greater than 30% or if signs and symptoms persist. NOTE: Methylene blue is available as follows: 50 mg/10 mL (5 mg/mL or 0.5% solution) single-dose ampules (Prod Info PROVAYBLUE(TM) intravenous injection, 2016) and 10 mg/1 mL (1% solution) vials (Prod Info methylene blue 1% intravenous injection, 2011). REPEAT DOSES: Additional doses may be required, especially for substances with prolonged absorption, slow elimination, or those that form metabolites that produce methemoglobin. NOTE: Large doses of methylene blue may cause methemoglobinemia or hemolysis (Howland, 2006). Improvement is usually noted shortly after administration if diagnosis is correct. Consider other diagnoses or treatment options if no improvement has been observed after several doses. If intravenous access cannot be established, methylene blue may also be given by intraosseous infusion. Methylene blue should not be given by subcutaneous or intrathecal injection (Prod Info methylene blue 1% intravenous injection, 2011; Herman et al, 1999). NEONATES: DOSE: 0.3 to 1 mg/kg (Hjelt et al, 1995).
b) CONTRAINDICATIONS: G-6-PD deficiency (methylene blue may cause hemolysis), known hypersensitivity to methylene blue, methemoglobin reductase deficiency (Shepherd & Keyes, 2004)
c) FAILURE: Failure of methylene blue therapy suggests: inadequate dose of methylene blue, inadequate decontamination, NADPH dependent methemoglobin reductase deficiency, hemoglobin M disease, sulfhemoglobinemia, or G-6-PD deficiency. Methylene blue is reduced by methemoglobin reductase and nicotinamide adenosine dinucleotide phosphate (NADPH) to leukomethylene blue. This in turn reduces methemoglobin. Red blood cells of patients with G-6-PD deficiency do not produce enough NADPH to convert methylene blue to leukomethylene blue (do Nascimento et al, 2008).
d) DRUG INTERACTION: Concomitant use of methylene blue with serotonergic drugs, including serotonin reuptake inhibitors (SRIs), selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), norepinephrine-dopamine reuptake inhibitors (NDRIs), triptans, and ergot alkaloids may increase the risk of potentially fatal serotonin syndrome (U.S. Food and Drug Administration, 2011; Stanford et al, 2010; Prod Info methylene blue 1% IV injection, 2011).

3) TOLUIDINE BLUE OR TOLONIUM CHLORIDE (GERMANY)

a) DOSE: 2 to 4 mg/kg intravenously over 5 minutes. Dose may be repeated in 30 minutes (Nemec, 2011; Lindenmann et al, 2006; Kiese et al, 1972).
b) SIDE EFFECTS: Hypotension with rapid intravenous administration. Vomiting, diarrhea, excessive sweating, hypotension, dysrhythmias, hemolysis, agranulocytosis and acute renal insufficiency after overdose (Dunipace et al, 1992; Hix & Wilson, 1987; Winek et al, 1969; Teunis et al, 1970; Marquez & Todd, 1959).
c) CONTRAINDICATIONS: G-6-PD deficiency; may cause hemolysis.

F) HYPOGLYCEMIA

1) Monitor blood sugar. Elevated blood sugar early in the clinical course may be evidence of glycogenolysis and could be followed by sudden, severe hypoglycemia requiring immediate glucose treatment. Severe hypoglycemia may appear without preceding hyperglycemia.

G) PYRIDOXINE

1) Pyridoxine may be antidotal for coma and seizures (Kirklin et al, 1976), as well as for the milder CNS effects of hydrazine poisoning (Frierson, 1965).
2) Doses suggested in case reports include pyridoxine 25 mg/kg parenterally. In one case, this produced rapid reversal of coma in 4 hours in a patient who had been comatose for over 60 hours (Kirklin et al, 1976).
3) Inhalation of a mixture of hydrazine and unsymmetrical dimethylhydrazine produced one case of mild symptoms (twitching, nausea, headache, and dyspnea). These symptoms, but not pulmonary edema, were eliminated by 200 mg of pyridoxine IV and 400 mg IM (Frierson, 1965).
4) Experimental animal studies indicated pyridoxine to be effective against unsymmetrical dimethylhydrazine, but not hydrazine. When used to treat experimental animals exposed to hydrazine-unsymmetrical dimethylhydrazine mixtures, pyridoxine was less effective (Azar et al, 1970). Predictions of its usefulness vary by species (Clark et al, 1968).
5) CAUTIONS

a) Pyridoxine doses of 0.2 to 5 g/day for 2 to 40 months have caused ataxia and severe sensory nervous system dysfunction (Schaumburg, 1983) (Parry & Bredesen, 1985) (Berger & Schaumburg, 1984) (Dalton, 1985). The maximum nontoxic pyridoxine dose is unknown.
b) Case reports have described only the use of single parenteral doses for the treatment of hydrazine toxicity. One study reports the use of 10 g of pyridoxine IV in a 24-year-old man who ingested "a mouthful" of hydrazine.

1) One week later the patient developed paresthesias of his hands and feet and mild distal limb weakness. Three weeks post-injection he had diminished pinprick, vibration, touch and position senses in his distal arms to the wrists and distal legs to the ankles.
2) The peripheral neuropathy spontaneously cleared over the next 6 months. Although the neuropathy may have been due to the hydrazine, the symptoms are also similar to those of pyridoxine neuro toxicity (Harati & Niakan, 1986).

H) MONITORING OF PATIENT

1) Monitor liver function tests as hydrazines are hepatotoxic.

I) Treatment should include recommendations listed in the ORAL EXPOSURE section when appropriate.

Enhanced Elimination

A)

1) DIURESIS: Maintain adequate urine output.
2) RENAL EXCRETION: Increased urine flow with saline or mannitol to a level of 10 to 15 mL/min with alkalinization may aid in preventing renal failure from tubular deposition of RBC breakdown products if hemolysis occurs (Clark et al, 1968). The usefulness of this treatment may be limited by hydrazine-induced nephrotoxicity; it could precipitate or worsen pulmonary edema.
3) HEMODIALYSIS/PERITONEAL DIALYSIS: These treatments might be effective if renal failure occurs, but there are no human data (Clark et al, 1968).

Abstracts

Range Of Toxicity

Summary

A)

B)

Minimum Lethal Exposure

A)

1) The minimum lethal human dose to this agent has not been delineated.

Maximum Tolerated Exposure

A)

1) The therapeutic dose of phenylhydrazine hydrochloride for treatment of polycythemia rubra vera was 0.2 g/day three or four times, followed by 0.1 g/day until the desired hemoglobin level was achieved, usually after a total dose of 1 to 3 grams (Clayton & Clayton, 1981).
2) Patients were given phenylhydrazine hydrochloride at varying doses for up to 35 weeks. Doses ranged from 25 to 150 mg/day, depending on the hematocrit (Pengelly, 1979).
3) The drug was given for as long as four years. Normal erythrocyte counts were maintained without further therapy in some patients, but not in others (Giffin & Allen, 1933).
4) Due to its potential toxicity and availability of other treatments, phenylhydrazine is no longer used clinically (Clayton & Clayton, 1994).
5) Persons with glucose-6-phosphate dehydrogenase deficiency (G-6-PD) may be hypersensitive to the hemolytic effects of phenylhydrazine, as this reagent is used to diagnose the deficiency in vitro (Clayton & Clayton, 1981).

B)

1) ADULT

a) One woman received phenylhydrazine hydrochloride treatment intermittently for 11 years without developing liver or kidney damage. Cirrhosis of the liver was evident at autopsy, but could not be clearly ascribed to the treatment (Stealy & Sumerlin, 1944).

C)

1) Rabbits survived a single dermal application of doses as high as 0.5 g/kg, but cyanosis, liver and spleen damage, and hemolytic anemia were seen (Derelanko et al, 1987).

Workplace Standards

A)

1) Not Listed

B)

1) Not Listed

C)

1) ACGIH (American Conference of Governmental Industrial Hygienists, 2010): Not Listed
2) EPA (U.S. Environmental Protection Agency, 2011): Not Listed
3) IARC (International Agency for Research on Cancer (IARC), 2016; International Agency for Research on Cancer, 2015; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2010; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2010a; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2008; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2007; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2006; IARC, 2004): Not Listed
4) NIOSH (National Institute for Occupational Safety and Health, 2007): Not Listed
5) MAK (DFG, 2002): Not Listed
6) NTP (U.S. Department of Health and Human Services, Public Health Service, National Toxicology Project ): Not Listed

D)

1) Not Listed

Toxicity Information

7.7.1)

A) References: RTECS, 1996

1) LD50- (ORAL)MOUSE:

a) 2100 mg/kg

2) LD50- (SUBCUTANEOUS)MOUSE:

a) 89 mg/kg

3) LD50- (INTRAPERITONEAL)RAT:

a) 161 mg/kg

Pharmacology Toxicology

Physicochemical

Physical Characteristics

A)

Molecular Weight

A)

Animal Toxicology

References

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PHENYLHYDRAZINE HYDROCHLORIDE

Classification | Detailed evidence-based information

Therapeutic Toxic Class

Specific Substances

Life Support

Clinical Effects

Laboratory Monitoring

Treatment Overview

Range Of Toxicity

Hepatic

Genitourinary

Hematologic

Dermatologic

Musculoskeletal

Endocrine

Reproductive

Carcinogenicity

Summary Of Exposure

Vital Signs

Heent

Cardiovascular

Respiratory

Neurologic

Gastrointestinal

Genotoxicity

Monitoring Parameters Levels

Life Support

Monitoring

Oral Exposure

Inhalation Exposure

Eye Exposure

Dermal Exposure

Enhanced Elimination

Summary

Minimum Lethal Exposure

Maximum Tolerated Exposure

Workplace Standards

Toxicity Information

Physical Characteristics

Molecular Weight

General Bibliography