6.5.1) PREVENTION OF ABSORPTION/PREHOSPITAL
A) Prehospital gastrointestinal decontamination is not recommended because of the potential for agitation and seizures and subsequent aspiration.
6.5.2) PREVENTION OF ABSORPTION
A) SUMMARY 1) Gastrointestinal decontamination is often NOT needed because the patient presents several hours after ingestion when absorption is complete. Administer activated charcoal if recent ingestion or possibility of coingestants, and only if the patient is cooperative and can protect their airway or is intubated. Administer to body stuffers that are not at risk for aspiration.
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).
6.5.3) TREATMENT
A) MONITORING OF PATIENT 1) Plasma levels are not clinically useful or readily available.
2) Standard urine toxicology screen may not produce a positive result for many 2C agents.
3) Monitor vital signs and mental status.
4) Monitor serum electrolytes and renal function.
5) Obtain ECG and institute continuous cardiac monitoring in patients with moderate to severe toxicity (ie, agitation, delirium, seizures, coma, hypotension).
6) Monitor creatinine phosphokinase in patients with prolonged agitation, seizures or coma; monitor renal function and urine output in patients with rhabdomyolysis.
B) PSYCHOMOTOR AGITATION 1) INDICATION a) If patient is severely agitated, sedate with IV benzodiazepines.
2) DIAZEPAM DOSE a) ADULT: 5 to 10 mg IV initially, repeat every 5 to 20 minutes as needed (Brophy et al, 2012; Prod Info diazepam IM, IV injection, 2008; Manno, 2003).
b) 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 (Loddenkemper & Goodkin, 2011; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008).
3) LORAZEPAM DOSE a) ADULT: 2 to 4 mg IV initially; repeat every 5 to 10 minutes as needed (Manno, 2003).
b) 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 (Brophy et al, 2012; Loddenkemper & Goodkin, 2011; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008).
4) Extremely large doses of benzodiazepines may be required in patients with severe intoxication in order to obtain adequate sedation. Titrate dose to clinical response and monitor for hypotension, CNS and respiratory depression, and the need for endotracheal intubation. 5) Phenothiazines are not routinely recommended due to undesirable side effects (orthostatic hypotension and mental status changes) (Grinspoon & Hedblom, 1975; Snyder et al, 1970; Solursh & Clement, 1968). 6) NEUROLEPTICS a) ZIPRASIDONE: Oral ziprasidone was used to treat episodes of aggressiveness in an 18-year-old man who used 25I-NBOMe (Rose et al, 2013). However, neuroleptic agents can cause QT prolongation and increase the risk of developing ventricular dysrhythmias. Neuroleptics should be avoided in patients with known QT prolongation (Dean et al, 2013).
b) HALOPERIDOL: Haloperidol has been protective in mice against lethality and hyperthermia caused by some but not all hallucinogenic amphetamines (Nichols et al, 1975; Davis & Borne, 1984; Paton et al, 1975). There are no data in humans. The mechanism of action is presumed to be dopaminergic blockade. Because haloperidol lowers seizure threshold and predisposes to hyperthermia, benzodiazepines are preferred.
c) CASE REPORT: A 40-year-old man without a history of a mental disorder, presented in a delusional state with incoherent speech after ingesting a sexual enhancing product containing 2C-T-4. Six hours after ingestion, the patient was overcome with extreme fear which prompted emergency treatment. The patient was treated with neuroleptic medication and recovered without neurological deficit approximately 17 hours after ingestion (Miyajima et al, 2008).
7) KETAMINE a) Since benzodiazepines and neuroleptics have a slow onset of action via the IM route, ketamine has been suggested as an alternative chemical restraint in patients with excited delirium. Ketamine has a rapid onset, predictable ability to induce a dissociated state, and lack of cardiovascular or respiratory depression. However, airway compromise, including laryngospasm and hypoxia may occur following ketamine therapy. In addition, ketamine can cause stimulatory cardiovascular effects resulting in increased tachycardia and hypertension (Dean et al, 2013).
8) PHENOBARBITAL a) Phenobarbital has been protective against lethality in mice but there are no human data (Thiessen & Cook, 1973b) (David & Borne, 1984) (Paton et al, 1975).
C) 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, 2010; 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).
7) RECURRING SEIZURES a) If seizures are not controlled by the above measures, patients will require endotracheal intubation, mechanical ventilation, continuous EEG monitoring, a continuous infusion of an anticonvulsant, and may require neuromuscular paralysis and vasopressor support. Consider continuous infusions of the following agents: 1) MIDAZOLAM: ADULT DOSE: An initial dose of 0.2 mg/kg slow bolus, at an infusion rate of 2 mg/minute; maintenance doses of 0.05 to 2 mg/kg/hour continuous infusion dosing, titrated to EEG (Brophy et al, 2012). PEDIATRIC DOSE: 0.1 to 0.3 mg/kg followed by a continuous infusion starting at 1 mcg/kg/minute, titrated upwards every 5 minutes as needed (Loddenkemper & Goodkin, 2011).
2) PROPOFOL: ADULT DOSE: Start at 20 mcg/kg/min with 1 to 2 mg/kg loading dose; maintenance doses of 30 to 200 mcg/kg/minute continuous infusion dosing, titrated to EEG; caution with high doses greater than 80 mcg/kg/minute in adults for extended periods of time (ie, longer than 48 hours) (Brophy et al, 2012); PEDIATRIC DOSE: IV loading dose of up to 2 mg/kg; maintenance doses of 2 to 5 mg/kg/hour may be used in older adolescents; avoid doses of 5 mg/kg/hour over prolonged periods because of propofol infusion syndrome (Loddenkemper & Goodkin, 2011); caution with high doses greater than 65 mcg/kg/min in children for extended periods of time; contraindicated in small children (Brophy et al, 2012).
3) PENTOBARBITAL: ADULT DOSE: A loading dose of 5 to 15 mg/kg at an infusion rate of 50 mg/minute or lower; may administer additional 5 to 10 mg/kg. Maintenance dose of 0.5 to 5 mg/kg/hour continuous infusion dosing, titrated to EEG (Brophy et al, 2012). PEDIATRIC DOSE: A loading dose of 3 to 15 mg/kg followed by a maintenance dose of 1 to 5 mg/kg/hour (Loddenkemper & Goodkin, 2011).
4) THIOPENTAL: ADULT DOSE: 2 to 7 mg/kg, at an infusion rate of 50 mg/minute or lower. Maintenance dose of 0.5 to 5 mg/kg/hour continuous infusing dosing, titrated to EEG (Brophy et al, 2012)
b) Endotracheal intubation, mechanical ventilation, and vasopressors will be required (Brophy et al, 2012) and consultation with a neurologist is strongly advised. c) Neuromuscular paralysis (eg, rocuronium bromide, a short-acting nondepolarizing agent) may be required to avoid hyperthermia, severe acidosis, and rhabdomyolysis. If rhabdomyolysis is possible, avoid succinylcholine chloride, because of the risk of hyperkalemic-induced cardiac dysrhythmias. Continuous EEG monitoring is mandatory if neuromuscular paralysis is used (Manno, 2003). D) SEROTONIN SYNDROME 1) SUMMARY a) Benzodiazepines are the mainstay of therapy. Cyproheptadine, a 5-HT antagonist, is also commonly used. Severe cases have been managed with benzodiazepine sedation and neuromuscular paralysis with non-depolarizing agents(Claassen & Gelissen, 2005).
2) HYPERTHERMIA a) Control agitation and muscle activity. Undress patient and enhance evaporative heat loss by keeping skin damp and using cooling fans.
b) MUSCLE ACTIVITY: Benzodiazepines are the drug of choice to control agitation and muscle activity. DIAZEPAM: ADULT: 5 to 10 mg IV every 5 to 10 minutes as needed, monitor for respiratory depression and need for intubation. CHILD: 0.25 mg/kg IV every 5 to 10 minutes; monitor for respiratory depression and need for intubation.
c) Non-depolarizing paralytics may be used in severe cases.
3) CYPROHEPTADINE a) Cyproheptadine is a non-specific 5-HT antagonist that has been shown to block development of serotonin syndrome in animals (Sternbach, 1991). Cyproheptadine has been used in the treatment of serotonin syndrome (Mills, 1997; Goldberg & Huk, 1992). There are no controlled human trials substantiating its efficacy.
b) ADULT: 12 mg initially followed by 2 mg every 2 hours if symptoms persist, up to a maximum of 32 mg in 24 hours. Maintenance dose 8 mg orally repeated every 6 hours (Boyer & Shannon, 2005).
c) CHILD: 0.25 mg/kg/day divided every 6 hours, maximum dose 12 mg/day (Mills, 1997).
4) HYPERTENSION a) Monitor vital signs regularly. For mild/moderate asymptomatic hypertension, pharmacologic intervention is usually not necessary.
5) HYPOTENSION a) Administer 10 to 20 mL/kg 0.9% saline bolus and place patient supine. Further fluid therapy should be guided by central venous pressure or right heart catheterization to avoid volume overload. b) Pressor agents with dopaminergic effects may theoretically worsen serotonin syndrome and should be used with caution. Direct acting agents (norepinephrine, epinephrine, phentolamine) are theoretically preferred. c) NOREPINEPHRINE 1) PREPARATION: Add 4 mL of 0.1% solution to 1000 mL of dextrose 5% in water to produce 4 mcg/mL. 2) INITIAL DOSE a) ADULT: 2 to 3 mL (8 to 12 mcg)/minute.
b) ADULT or CHILD: 0.1 to 0.2 mcg/kg/min. Titrate to maintain adequate blood pressure.
3) MAINTENANCE DOSE a) 0.5 to 1 mL (2 to 4 mcg)/minute.
6) SEIZURES a) DIAZEPAM 1) MAXIMUM RATE: Administer diazepam IV over 2 to 3 minutes (maximum rate: 5 mg/min).
2) ADULT DIAZEPAM DOSE: 5 to 10 mg initially, repeat every 5 to 10 minutes as needed. Monitor for hypotension, respiratory depression and the need for endotracheal intubation. Consider a second agent if seizures persist or recur after diazepam 30 milligrams.
3) PEDIATRIC DIAZEPAM DOSE: 0.2 to 0.5 mg/kg, repeat every 5 minutes as needed. Monitor for hypotension, respiratory depression and the need for endotracheal intubation. Consider a second agent if seizures persist or recur after diazepam 10 milligrams in children over 5 years or 5 milligrams in children under 5 years of age.
4) RECTAL USE: If an intravenous line cannot be established, diazepam may be given per rectum (not FDA approved), or lorazepam may be given intramuscularly.
b) LORAZEPAM 1) MAXIMUM RATE: The rate of IV administration of lorazepam should not exceed 2 mg/min (Prod Info Ativan(R), 1991).
2) ADULT LORAZEPAM DOSE: 2 to 4 mg IV. Initial doses may be repeated in 10 to 15 minutes, if seizures persist (Prod Info ATIVAN(R) injection, 2003).
3) PEDIATRIC LORAZEPAM DOSE: 0.1 mg/kg IV push (range: 0.05 to 0.1 mg/kg; maximum dose 4 mg); may repeat dose in 5 to 10 minutes if seizures continue. It has also been given rectally at the same dose in children with no IV access (Sreenath et al, 2010; Chin et al, 2008; Wheless, 2004; Qureshi et al, 2002; De Negri & Baglietto, 2001; Mitchell, 1996; Appleton, 1995; Giang & McBride, 1988).
c) RECURRING SEIZURES 1) If seizures cannot be controlled with diazepam or recur, give phenobarbital or propofol.
d) PHENOBARBITAL 1) SERUM LEVEL MONITORING: Monitor serum levels over next 12 to 24 hours for maintenance of therapeutic levels (15 to 25 mcg/mL).
2) ADULT PHENOBARBITAL LOADING DOSE: 600 to 1200 mg of phenobarbital IV initially (10 to 20 mg/kg) diluted in 60 mL of 0.9% saline given at 25 to 50 mg/minute.
3) ADULT PHENOBARBITAL MAINTENANCE DOSE: Additional doses of 120 to 240 mg may be given every 20 minutes.
4) MAXIMUM SAFE ADULT PHENOBARBITAL DOSE: No maximum safe dose has been established. Patients in status epilepticus have received as much as 100 mg/min until seizure control was achieved or a total dose of 10 mg/kg.
5) PEDIATRIC PHENOBARBITAL LOADING DOSE: 15 to 20 mg/kg of phenobarbital intravenously at a rate of 25 to 50 mg/min.
6) PEDIATRIC PHENOBARBITAL MAINTENANCE DOSE: Repeat doses of 5 to 10 mg/kg may be given every 20 minutes.
7) MAXIMUM SAFE PEDIATRIC PHENOBARBITAL DOSE: No maximum safe dose has been established. Children in status epilepticus have received doses of 30 to 120 mg/kg within 24 hours. Vasopressors and mechanical ventilation were needed in some patients receiving these doses.
8) NEONATAL PHENOBARBITAL LOADING DOSE: 20 to 30 mg/kg IV at a rate of no more than 1 mg/kg/min in patients with no preexisting phenobarbital serum levels.
9) NEONATAL PHENOBARBITAL MAINTENANCE DOSE: Repeat doses of 2.5 mg/kg every 12 hours may be given; adjust dosage to maintain serum levels of 20 to 40 mcg/mL.
10) MAXIMUM SAFE NEONATAL PHENOBARBITAL DOSE: Doses of up to 20 mg/kg/min up to a total of 30 mg/kg have been tolerated in neonates.
11) CAUTION: Adequacy of ventilation must be continuously monitored in children and adults. Intubation may be necessary with increased doses.
7) CHLORPROMAZINE a) Chlorpromazine is a 5-HT2 receptor antagonist that has been used to treat cases of serotonin syndrome (Graham, 1997; Gillman, 1996). Controlled human trial documenting its efficacy are lacking.
b) ADULT: 25 to 100 mg intramuscularly repeated in 1 hour if necessary.
c) CHILD: 0.5 to 1 mg/kg repeated as needed every 6 to 12 hours not to exceed 2 mg/kg/day.
8) NOT RECOMMENDED a) BROMOCRIPTINE: It has been used in the treatment of neuroleptic malignant syndrome but is NOT RECOMMENDED in the treatment of serotonin syndrome as it has serotonergic effects (Gillman, 1997). In one case the use of bromocriptine was associated with a fatal outcome (Kline et al, 1989).
E) HYPERTENSIVE EPISODE 1) SUMMARY: Hypertension often resolves once the patient is less agitated (ie, following benzodiazepine administration). If severe hypertension associated with end organ damage persists, use of nitroprusside or a calcium channel blocker is suggested; use of beta-blockers is generally contraindicated since these agents may worsen vasospasm and result in hypertension (Shannon, 2000). As hypotension may develop later, a short acting titratable agent is preferred for treating hypertension. 2) Monitor vital signs regularly. For mild/moderate hypertension without evidence of end organ damage, pharmacologic intervention is generally not necessary. Sedative agents such as benzodiazepines may be helpful in treating hypertension and tachycardia in agitated patients, especially if a sympathomimetic agent is involved in the poisoning. 3) For hypertensive emergencies (severe hypertension with evidence of end organ injury (CNS, cardiac, renal), or emergent need to lower mean arterial pressure 20% to 25% within one hour), sodium nitroprusside is preferred. Nitroglycerin and phentolamine are possible alternatives. 4) SODIUM NITROPRUSSIDE/INDICATIONS a) Useful for emergent treatment of severe hypertension secondary to poisonings. Sodium nitroprusside has a rapid onset of action, a short duration of action and a half-life of about 2 minutes (Prod Info NITROPRESS(R) injection for IV infusion, 2007) that can allow accurate titration of blood pressure, as the hypertensive effects of drug overdoses are often short lived.
5) SODIUM NITROPRUSSIDE/DOSE a) ADULT: Begin intravenous infusion at 0.1 microgram/kilogram/minute and titrate to desired effect; up to 10 micrograms/kilogram/minute may be required (American Heart Association, 2005). Frequent hemodynamic monitoring and administration by an infusion pump that ensures a precise flow rate is mandatory (Prod Info NITROPRESS(R) injection for IV infusion, 2007). PEDIATRIC: Initial: 0.5 to 1 microgram/kilogram/minute; titrate to effect up to 8 micrograms/kilogram/minute (Kleinman et al, 2010).
6) SODIUM NITROPRUSSIDE/SOLUTION PREPARATION a) The reconstituted 50 mg solution must be further diluted in 250 to 1000 mL D5W to desired concentration (recommended 50 to 200 mcg/mL) (Prod Info NITROPRESS(R) injection, 2004). Prepare fresh every 24 hours; wrap in aluminum foil. Discard discolored solution (Prod Info NITROPRESS(R) injection for IV infusion, 2007).
7) SODIUM NITROPRUSSIDE/MAJOR ADVERSE REACTIONS a) Severe hypotension; headaches, nausea, vomiting, abdominal cramps; thiocyanate or cyanide toxicity (generally from prolonged, high dose infusion); methemoglobinemia; lactic acidosis; chest pain or dysrhythmias (high doses) (Prod Info NITROPRESS(R) injection for IV infusion, 2007). The addition of 1 gram of sodium thiosulfate to each 100 milligrams of sodium nitroprusside for infusion may help to prevent cyanide toxicity in patients receiving prolonged or high dose infusions (Prod Info NITROPRESS(R) injection for IV infusion, 2007).
8) SODIUM NITROPRUSSIDE/MONITORING PARAMETERS a) Monitor blood pressure every 30 to 60 seconds at onset of infusion; once stabilized, monitor every 5 minutes. Continuous blood pressure monitoring with an intra-arterial catheter is advised (Prod Info NITROPRESS(R) injection for IV infusion, 2007).
9) PHENTOLAMINE/INDICATIONS a) Useful for severe hypertension, particularly if caused by agents with alpha adrenergic agonist effects usually induced by catecholamine excess (Rhoney & Peacock, 2009).
10) PHENTOLAMINE/ADULT DOSE a) BOLUS DOSE: 5 to 15 mg IV bolus repeated as needed (U.S. Departement of Health and Human Services, National Institutes of Health, and National Heart, Lung, and Blood Institute, 2004). Onset of action is 1 to 2 minutes with a duration of 10 to 30 minutes (Rhoney & Peacock, 2009).
b) CONTINUOUS INFUSION: 1 mg/hr, adjusted hourly to stabilize blood pressure. Prepared by adding 60 mg of phentolamine mesylate to 100 mL of 0.9% sodium chloride injection; continuous infusion ranging from 12 to 52 mg/hr over 4 days has been used in case reports (McMillian et al, 2011).
11) PHENTOLAMINE/PEDIATRIC DOSE a) 0.05 to 0.1 mg/kg/dose (maximum of 5 mg per dose) intravenously every 5 minutes until hypertension is controlled, then every 2 to 4 hours as needed (Singh et al, 2012; Koch-Weser, 1974).
12) PHENTOLAMINE/ADVERSE EFFECTS a) Adverse events can include orthostatic or prolonged hypotension, tachycardia, dysrhythmias, angina, flushing, headache, nasal congestion, nausea, vomiting, abdominal pain and diarrhea (Rhoney & Peacock, 2009; Prod Info Phentolamine Mesylate IM, IV injection Sandoz Standard, 2005).
13) CAUTION a) Phentolamine should be used with caution in patients with coronary artery disease because it may induce angina or myocardial infarction (Rhoney & Peacock, 2009).
14) LABETALOL a) INTRAVENOUS INDICATIONS 1) Consider if severe hypertension is unresponsive to short acting titratable agents such as sodium nitroprusside. Although labetalol has mixed alpha and beta adrenergic effects (Pearce & Wallin, 1994), it should be used cautiously if sympathomimetic agents are involved in the poisoning, as worsening hypertension may develop from alpha adrenergic effects.
b) ADULT DOSE 1) INTRAVENOUS BOLUS: Initial dose of 20 mg by slow IV injection over 2 minutes. Repeat with 40 to 80 mg at 10 minute intervals. Maximum total dose: 300 mg. Maximum effects on blood pressure usually occur within 5 minutes (Prod Info Trandate(R) IV injection, 2010).
2) INTRAVENOUS INFUSION: Administer infusion after initial bolus, until desired blood pressure is reached. Administer IV at 2 mg/min of diluted labetalol solution (1 mg/mL or 2 mg/3 mL concentrations); adjust as indicated and continue until adequate response is achieved; usual effective IV dose range is 50 to 200 mg total dose; maximum dose: 300 mg. Prepare 1 mg/mL concentration by adding 200 mg labetalol (40 mL) to 160 mL of a compatible solution and administered at a rate of 2 mL/min (2 mg/min); also can be mixed as an approximate 2 mg/3 mL concentration by adding 200 mg labetalol (40 mL) to 250 mL of solution and administered at a rate of 3 mL/min (2 mg/min) (Prod Info Trandate(R) IV injection, 2010). Use of an infusion pump is recommended (Prod Info Trandate(R) IV injection, 2010).
c) PEDIATRIC DOSE 1) INTRAVENOUS: LOADING DOSE: 0.2 to 1 mg/kg, may repeat every 5 to 10 minutes (Hari & Sinha, 2011; Flynn & Tullus, 2009; Temple & Nahata, 2000; Fivush et al, 1997; Fivush et al, 1997; Bunchman et al, 1992). Maximum dose: 40 mg/dose (Hari & Sinha, 2011; Flynn & Tullus, 2009). CONTINUOUS INFUSION: 0.25 to 3 mg/kg/hour IV (Hari & Sinha, 2011; Flynn & Tullus, 2009; Temple & Nahata, 2000; Fivush et al, 1997; Miller, 1994; Deal et al, 1992; Bunchman et al, 1992).
d) ADVERSE REACTIONS 1) Common adverse events include postural hypotension, dizziness; fatigue; nausea; vomiting, sweating, and flushing (Pearce & Wallin, 1994).
e) PRECAUTIONS 1) Contraindicated in patients with bronchial asthma, congestive heart failure, greater than first degree heart block, cardiogenic shock, or severe bradycardia or other conditions associated with prolonged or severe hypotension. In patients with pheochromocytoma, labetalol should be used with caution because it has produced a paradoxical hypertensive response in some patients with this tumor (Prod Info Trandate(R) IV injection, 2010).
2) Use caution in hepatic disease or intermittent claudication; effects of halothane may be enhanced by labetalol (Prod Info Trandate(R) IV injection, 2010). Labetalol should be stopped if there is laboratory evidence of liver injury or jaundice (Prod Info Trandate(R) IV injection, 2010).
f) MONITORING PARAMETER 1) Monitor blood pressure frequently during initial dosing and infusion (Prod Info Trandate(R) IV injection, 2010).
15) ALPHA BLOCKERS: Phentolamine and phenoxybenzamine have been shown to block the pressor response in mice. 16) BETA BLOCKERS: May lead to increased hypertension due to unopposed alpha stimulation, unless a vasodilator is given concurrently. May be used with nitroprusside. A short acting cardioselective agent such as esmolol is preferred. F) BODY TEMPERATURE ABOVE REFERENCE RANGE 1) Hyperthermia occurs in severe cases (Dean et al, 2013; Drees et al, 2009). It may be life threatening, and has been contributory to death (Dean et al, 2013). It should be treated aggressively.
2) Core temperature above 40 degrees C may be life threatening and indicates the need for rapid sedation and cooling.
3) External cooling measures should be provided by accelerating evaporative heat loss by keeping the patient's skin wet with cool water and placing fans in the room. Rapid cooling measures including placing the patient in an ice bath may be required. Monitor temperature every continuously by rectal probe, or every 30 minutes until below 38 degrees centigrade.
4) Administer intravenous benzodiazepines. Large doses may be required. Monitor respiratory adequacy and airway. Be prepared to intubate and ventilate if needed.
5) Intubation with neuromuscular paralysis and sedation may be required in severe cases.
G) TACHYARRHYTHMIA 1) Sedation with benzodiazepines to control agitation is sufficient in the vast majority of cases. Administer oxygen and intravenous fluids and correct hyperthermia as clinically indicated. If severe tachycardia persists and is associated with hemodynamic compromise or myocardial ischemia, additional therapy may be required, but this is unusual. Small incremental doses of labetalol may be useful because of combined alpha and beta blocking effects. A short-acting agent such as esmolol may also be considered, however esmolol carries the risk of inducing hypertension due to unopposed alpha agonist effects of amphetamines in this setting. 2) LABETALOL a) INTRAVENOUS INDICATIONS 1) Consider if severe hypertension is unresponsive to short acting titratable agents such as sodium nitroprusside. Although labetalol has mixed alpha and beta adrenergic effects (Pearce & Wallin, 1994), it should be used cautiously if sympathomimetic agents are involved in the poisoning, as worsening hypertension may develop from alpha adrenergic effects.
b) ADULT DOSE 1) INTRAVENOUS BOLUS: Initial dose of 20 mg by slow IV injection over 2 minutes. Repeat with 40 to 80 mg at 10 minute intervals. Maximum total dose: 300 mg. Maximum effects on blood pressure usually occur within 5 minutes (Prod Info Trandate(R) IV injection, 2010).
2) INTRAVENOUS INFUSION: Administer infusion after initial bolus, until desired blood pressure is reached. Administer IV at 2 mg/min of diluted labetalol solution (1 mg/mL or 2 mg/3 mL concentrations); adjust as indicated and continue until adequate response is achieved; usual effective IV dose range is 50 to 200 mg total dose; maximum dose: 300 mg. Prepare 1 mg/mL concentration by adding 200 mg labetalol (40 mL) to 160 mL of a compatible solution and administered at a rate of 2 mL/min (2 mg/min); also can be mixed as an approximate 2 mg/3 mL concentration by adding 200 mg labetalol (40 mL) to 250 mL of solution and administered at a rate of 3 mL/min (2 mg/min) (Prod Info Trandate(R) IV injection, 2010). Use of an infusion pump is recommended (Prod Info Trandate(R) IV injection, 2010).
c) PEDIATRIC DOSE 1) INTRAVENOUS: LOADING DOSE: 0.2 to 1 mg/kg, may repeat every 5 to 10 minutes (Hari & Sinha, 2011; Flynn & Tullus, 2009; Temple & Nahata, 2000; Fivush et al, 1997; Fivush et al, 1997; Bunchman et al, 1992). Maximum dose: 40 mg/dose (Hari & Sinha, 2011; Flynn & Tullus, 2009). CONTINUOUS INFUSION: 0.25 to 3 mg/kg/hour IV (Hari & Sinha, 2011; Flynn & Tullus, 2009; Temple & Nahata, 2000; Fivush et al, 1997; Miller, 1994; Deal et al, 1992; Bunchman et al, 1992).
d) ADVERSE REACTIONS 1) Common adverse events include postural hypotension, dizziness; fatigue; nausea; vomiting, sweating, and flushing (Pearce & Wallin, 1994).
e) PRECAUTIONS 1) Contraindicated in patients with bronchial asthma, congestive heart failure, greater than first degree heart block, cardiogenic shock, or severe bradycardia or other conditions associated with prolonged or severe hypotension. In patients with pheochromocytoma, labetalol should be used with caution because it has produced a paradoxical hypertensive response in some patients with this tumor (Prod Info Trandate(R) IV injection, 2010).
2) Use caution in hepatic disease or intermittent claudication; effects of halothane may be enhanced by labetalol (Prod Info Trandate(R) IV injection, 2010). Labetalol should be stopped if there is laboratory evidence of liver injury or jaundice (Prod Info Trandate(R) IV injection, 2010).
f) MONITORING PARAMETER 1) Monitor blood pressure frequently during initial dosing and infusion (Prod Info Trandate(R) IV injection, 2010).
3) TACHYCARDIA SUMMARY a) Evaluate patient to be sure that tachycardia is not a physiologic response to dehydration, anemia, hypotension, fever, sepsis, or hypoxia. Sinus tachycardia does not generally require treatment unless hemodynamic compromise develops. b) If therapy is required, a short acting, cardioselective agent such as esmolol is generally preferred (Prod Info BREVIBLOC(TM) intravenous injection, 2012). c) ESMOLOL/ADULT LOADING DOSE 1) Infuse 500 micrograms/kilogram (0.5 mg/kg) IV over 1 minute (Neumar et al, 2010).
d) ESMOLOL/ADULT MAINTENANCE DOSE 1) Follow loading dose with infusion of 50 mcg/kg per minute (0.05 mg/kg per minute) (Neumar et al, 2010).
2) EVALUATION OF RESPONSE: If response is inadequate, infuse second loading bolus of 0.5 mg/kg over 1 minute and increase the maintenance infusion to 100 mcg/kg (0.1 mg/kg) per minute. Reevaluate therapeutic effect, increase in the same manner if required to a maximum infusion rate of 300 mcg/kg (0.3 mg/kg) per minute (Neumar et al, 2010).
3) The manufacturer recommends that a maximum of 3 loading doses be used (Prod Info BREVIBLOC(TM) intravenous injection, 2012).
4) END POINT OF THERAPY: As the desired heart rate or blood pressure is approached, omit loading dose and adjust maintenance infusion as required (Prod Info BREVIBLOC(TM) intravenous injection, 2012).
e) CAUTION 1) Esmolol is a short acting beta-adrenergic blocking agent with negative inotropic effects. Esmolol should be avoided in patients with asthma, obstructive airway disease, decompensated heart failure and pre-excited atrial fibrillation (wide complex irregular tachycardia) or atrial flutter (Neumar et al, 2010).
H) VENTRICULAR ARRHYTHMIA 1) VENTRICULAR DYSRHYTHMIAS SUMMARY a) Obtain an ECG, institute continuous cardiac monitoring and administer oxygen. Evaluate for hypoxia, acidosis, and electrolyte disorders (particularly hypokalemia, hypocalcemia, and hypomagnesemia). Lidocaine and amiodarone are generally first line agents for stable monomorphic ventricular tachycardia, particularly in patients with underlying impaired cardiac function. Amiodarone should be used with caution if a substance that prolongs the QT interval and/or causes torsades de pointes is involved in the overdose. Unstable rhythms require immediate cardioversion.
2) LIDOCAINE a) LIDOCAINE/DOSE 1) ADULT: 1 to 1.5 milligrams/kilogram via intravenous push. For refractory VT/VF an additional bolus of 0.5 to 0.75 milligram/kilogram can be given at 5 to 10 minute intervals to a maximum dose of 3 milligrams/kilogram (Neumar et al, 2010). Only bolus therapy is recommended during cardiac arrest. a) Once circulation has been restored begin a maintenance infusion of 1 to 4 milligrams per minute. If dysrhythmias recur during infusion repeat 0.5 milligram/kilogram bolus and increase the infusion rate incrementally (maximal infusion rate is 4 milligrams/minute) (Neumar et al, 2010).
2) CHILD: 1 milligram/kilogram initial bolus IV/IO; followed by a continuous infusion of 20 to 50 micrograms/kilogram/minute (de Caen et al, 2015). b) LIDOCAINE/MAJOR ADVERSE REACTIONS 1) Paresthesias; muscle twitching; confusion; slurred speech; seizures; respiratory depression or arrest; bradycardia; coma. May cause significant AV block or worsen pre-existing block. Prophylactic pacemaker may be required in the face of bifascicular, second degree, or third degree heart block (Prod Info Lidocaine HCl intravenous injection solution, 2006; Neumar et al, 2010).
c) LIDOCAINE/MONITORING PARAMETERS 1) Monitor ECG continuously; plasma concentrations as indicated (Prod Info Lidocaine HCl intravenous injection solution, 2006).
3) AMIODARONE a) AMIODARONE/INDICATIONS 1) Effective for the control of hemodynamically stable monomorphic ventricular tachycardia. Also recommended for pulseless ventricular tachycardia or ventricular fibrillation in cardiac arrest unresponsive to CPR, defibrillation and vasopressor therapy (Link et al, 2015; Neumar et al, 2010). It should be used with caution when the ingestion involves agents known to cause QTc prolongation, such as fluoroquinolones, macrolide antibiotics or azoles, and when ECG reveals QT prolongation suspected to be secondary to overdose (Prod Info Cordarone(R) oral tablets, 2015).
b) AMIODARONE/ADULT DOSE 1) For ventricular fibrillation or pulseless VT unresponsive to CPR, defibrillation, and a vasopressor therapy give an initial dose of 300 mg IV followed by 1 dose of 150 mg IV. For stable ventricular tachycardias: Infuse 150 milligrams over 10 minutes, and repeat if necessary. Follow by a 1 milligram/minute infusion for 6 hours, then a 0.5 milligram/minute. Maximum total dose over 24 hours is 2.2 grams (Neumar et al, 2010).
c) AMIODARONE/PEDIATRIC DOSE 1) Infuse 5 milligrams/kilogram as a bolus for pulseless ventricular tachycardia or ventricular fibrillation; may repeat twice up to 15 mg/kg. Infuse 5 milligrams/kilogram over 20 to 60 minutes for perfusing tachycardias. Maximum single dose is 300 mg. Routine use with other drugs that prolong the QT interval is NOT recommended (Kleinman et al, 2010).
d) ADVERSE EFFECTS 1) Hypotension and bradycardia are the most common adverse effects (Neumar et al, 2010).
I) HYPOTENSIVE EPISODE 1) SUMMARY a) Infuse 10 to 20 milliliters/kilogram of isotonic fluid and keep the patient supine. If hypotension persists, administer dopamine or norepinephrine. Consider central venous pressure monitoring to guide further fluid therapy.
2) DOPAMINE a) DOSE: Begin at 5 micrograms per kilogram per minute progressing in 5 micrograms per kilogram per minute increments as needed (Prod Info dopamine hcl, 5% dextrose IV injection, 2004). If hypotension persists, dopamine may need to be discontinued and a more potent vasoconstrictor (eg, norepinephrine) should be considered (Prod Info dopamine hcl, 5% dextrose IV injection, 2004).
b) CAUTION: If ventricular dysrhythmias occur, decrease rate of administration (Prod Info dopamine hcl, 5% dextrose IV injection, 2004). Extravasation may cause local tissue necrosis, administration through a central venous catheter is preferred (Prod Info dopamine hcl, 5% dextrose IV injection, 2004).
3) NOREPINEPHRINE a) PREPARATION: 4 milligrams (1 amp) added to 1000 milliliters of diluent provides a concentration of 4 micrograms/milliliter of norepinephrine base. Norepinephrine bitartrate should be mixed in dextrose solutions (dextrose 5% in water, dextrose 5% in saline) since dextrose-containing solutions protect against excessive oxidation and subsequent potency loss. Administration in saline alone is not recommended (Prod Info norepinephrine bitartrate injection, 2005). b) DOSE 1) ADULT: Dose range: 0.1 to 0.5 microgram/kilogram/minute (eg, 70 kg adult 7 to 35 mcg/min); titrate to maintain adequate blood pressure (Peberdy et al, 2010).
2) CHILD: Dose range: 0.1 to 2 micrograms/kilogram/minute; titrate to maintain adequate blood pressure (Kleinman et al, 2010).
3) CAUTION: Extravasation may cause local tissue ischemia, administration by central venous catheter is advised (Peberdy et al, 2010).
J) VASOSPASM 1) Heparinization and intravenous or intraarterial nitroprusside have been used with success (Bowen et al, 1983).
K) RHABDOMYOLYSIS 1) SUMMARY: Early aggressive fluid replacement is the mainstay of therapy and may help prevent renal insufficiency. Diuretics such as mannitol or furosemide may be added if necessary to maintain urine output but only after volume status has been restored as hypovolemia will increase renal tubular damage. Urinary alkalinization is NOT routinely recommended.
2) Initial treatment should be directed towards controlling acute metabolic disturbances such as hyperkalemia, hyperthermia, and hypovolemia. Control seizures, agitation, and muscle contractions (Erdman & Dart, 2004).
3) FLUID REPLACEMENT: Early and aggressive fluid replacement is the mainstay of therapy to prevent renal failure. Vigorous fluid replacement with 0.9% saline (10 to 15 mL/kg/hour) is necessary even if there is no evidence of dehydration. Several liters of fluid may be needed within the first 24 hours (Walter & Catenacci, 2008; Camp, 2009; Huerta-Alardin et al, 2005; Criddle, 2003; Polderman, 2004). Hypovolemia, increased insensible losses, and third spacing of fluid commonly increase fluid requirements. Strive to maintain a urine output of at least 1 to 2 mL/kg/hour (or greater than 150 to 300 mL/hour) (Walter & Catenacci, 2008; Camp, 2009; Erdman & Dart, 2004; Criddle, 2003). To maintain a urine output this high, 500 to 1000 mL of fluid per hour may be required (Criddle, 2003). Monitor fluid input and urine output, plus insensible losses. Monitor for evidence of fluid overload and compartment syndrome; monitor serum electrolytes, CK, and renal function tests.
4) DIURETICS: Diuretics (eg, mannitol or furosemide) may be needed to ensure adequate urine output and to prevent acute renal failure when used in combination with aggressive fluid therapy. Loop diuretics increase tubular flow and decrease deposition of myoglobin. These agents should be used only after volume status has been restored, as hypovolemia will increase renal tubular damage. If the patient is maintaining adequate urine output, loop diuretics are not necessary (Vanholder et al, 2000).
5) URINARY ALKALINIZATION: Alkalinization of the urine is not routinely recommended, as it has never been documented to reduce nephrotoxicity, and may cause complications such as hypocalcemia and hypokalemia (Walter & Catenacci, 2008; Huerta-Alardin et al, 2005; Brown et al, 2004; Polderman, 2004). Retrospective studies have failed to demonstrate any clinical benefit from the use of urinary alkalinization (Brown et al, 2004; Polderman, 2004; Homsi et al, 1997).
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