6.5.1) PREVENTION OF ABSORPTION/PREHOSPITAL
A) ACTIVATED CHARCOAL 1) PREHOSPITAL ACTIVATED CHARCOAL ADMINISTRATION a) Consider prehospital administration of activated charcoal as an aqueous slurry in patients with a potentially toxic ingestion who are awake and able to protect their airway. Activated charcoal is most effective when administered within one hour of ingestion. Administration in the prehospital setting has the potential to significantly decrease the time from toxin ingestion to activated charcoal administration, although it has not been shown to affect outcome (Alaspaa et al, 2005; Thakore & Murphy, 2002; Spiller & Rogers, 2002). 1) In patients who are at risk for the abrupt onset of seizures or mental status depression, activated charcoal should not be administered in the prehospital setting, due to the risk of aspiration in the event of spontaneous emesis. 2) The addition of flavoring agents (cola drinks, chocolate milk, cherry syrup) to activated charcoal improves the palatability for children and may facilitate successful administration (Guenther Skokan et al, 2001; Dagnone et al, 2002).
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).
6.5.2) PREVENTION OF ABSORPTION
A) 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) SUPPORT 1) MANAGEMENT OF MILD TO MODERATE TOXICITY a) Treatment is symptomatic and supportive. Manage mild hypotension with IV fluids. For mild/moderate asymptomatic hypertension (no end organ damage), pharmacologic treatment is generally not necessary.
2) MANAGEMENT OF SEVERE TOXICITY a) Treatment is symptomatic and supportive. Correct any significant fluid and/or electrolyte abnormalities in patients with severe diarrhea and/or vomiting. Severe nausea and vomiting may respond to a combination of agents from different drug classes. For severe hypertension, nitroprusside is preferred. Labetalol, nitroglycerin, and phentolamine are alternatives. Treat severe hypotension with IV 0.9% NaCl at 10 to 20 mL/kg. Add dopamine or norepinephrine if unresponsive to fluids. Therapeutic doses of lenvatinib may cause prolongation of the QT interval. In patients with QT prolongation, monitor serum electrolytes including potassium, calcium and magnesium in patients with significant overdose; correct any abnormalities. At the time of this review, torsades de pointes has not been reported with therapy.
B) MONITORING OF PATIENT 1) Serum lenvatinib concentrations are not clinically useful in guiding management following overdose, or widely available in clinical practice. 2) Monitor vital signs, liver enzymes, and renal function following a significant overdose. 3) Monitor serum electrolytes, including calcium levels, in patients with significant vomiting and/or diarrhea. 4) Institute continuous cardiac monitoring and obtain serial ECGs. 5) If QT prolongation develops, monitor serum electrolytes including potassium, calcium and magnesium. Correct any abnormalities. 6) Monitor for evidence of arterial thromboembolic events. 7) Monitor CBC with differential and platelet count following an overdose. Monitor for clinical evidence of bleeding. 8) Monitor TSH levels in symptomatic patients.
C) VOMITING 1) SUMMARY a) TREATMENT OF BREAKTHROUGH NAUSEA AND VOMITING 1) Treat patients with high-dose dopamine (D2) receptor antagonists (eg, metoclopramide), phenothiazines (eg, prochlorperazine, promethazine), 5-HT3 serotonin antagonists (eg, dolasetron, granisetron, ondansetron), benzodiazepines (eg, lorazepam), corticosteroids (eg, dexamethasone), and antipsychotics (eg, haloperidol); diphenhydramine may be required to prevent dystonic reactions from dopamine antagonists, phenothiazines, and antipsychotics. It may be necessary to treat with multiple concomitant agents, from different drug classes, using alternating schedules or alternating routes. In general, rectal medications should be avoided in patients with neutropenia. 2) DOPAMINE RECEPTOR ANTAGONISTS: Metoclopramide: Adults: 10 to 40 mg orally or IV and then every 4 or 6 hours, as needed. Dose of 2 mg/kg IV every 2 to 4 hours for 2 to 5 doses may also be given. Monitor for dystonic reactions; add diphenhydramine 25 to 50 mg orally or IV every 4 to 6 hours as needed for dystonic reactions (None Listed, 1999). Children: 0.1 to 0.2 mg/kg IV every 6 hours; MAXIMUM: 10 mg/dose (Dupuis & Nathan, 2003). 3) PHENOTHIAZINES: Prochlorperazine: Adults: 25 mg suppository as needed every 12 hours or 10 mg orally or IV every 4 or 6 hours as needed; Children (2 yrs or older): 20 to 29 pounds: 2.5 mg orally 1 to 2 times daily (MAX 7.5 mg/day); 30 to 39 pounds: 2.5 mg orally 2 to 3 times daily (MAX 10 mg/day); 40 to 85 pounds: 2.5 mg orally 3 times daily or 5 mg orally twice daily (MAX 15 mg/day) OR 2 yrs or older and greater than 20 pounds: 0.06 mg/pound IM as a single dose (Prod Info COMPAZINE(R) tablets, injection, suppositories, syrup, 2004; Prod Info Compazine(R), 2002). Promethazine: Adults: 12.5 to 25 mg orally or IV every 4 hours; Children (2 yr and older) 12.5 to 25 mg OR 0.5 mg/pound orally every 4 to 6 hours as needed (Prod Info promethazine hcl rectal suppositories, 2007). Chlorpromazine: Children: greater than 6 months of age, 0.55 mg/kg orally every 4 to 6 hours, or IV every 6 to 8 hours; max of 40 mg per dose if age is less than 5 years or weight is less than 22 kg (None Listed, 1999). 4) SEROTONIN 5-HT3 ANTAGONISTS: Dolasetron: Adults: 100 mg orally daily or 1.8 mg/kg IV or 100 mg IV. Granisetron: Adults: 1 to 2 mg orally daily or 1 mg orally twice daily or 0.01 mg/kg (maximum 1 mg) IV or transdermal patch containing 34.3 mg granisetron. Ondansetron: Adults: 16 mg orally or 8 mg IV daily (Kris et al, 2006; None Listed, 1999); Children (older than 3 years of age): 0.15 mg/kg IV 4 and 8 hours after chemotherapy (None Listed, 1999). 5) BENZODIAZEPINES: Lorazepam: Adults: 1 to 2 mg orally or IM/IV every 6 hours; Children: 0.05 mg/kg, up to a maximum of 3 mg, orally or IV every 8 to 12 hours as needed (None Listed, 1999). 6) STEROIDS: Dexamethasone: Adults: 10 to 20 mg orally or IV every 4 to 6 hours; Children: 5 to 10 mg/m(2) orally or IV every 12 hours as needed; methylprednisolone: children: 0.5 to 1 mg/kg orally or IV every 12 hours as needed (None Listed, 1999). 7) ANTIPSYCHOTICS: Haloperidol: Adults: 1 to 4 mg orally or IM/IV every 6 hours as needed (None Listed, 1999).
D) STOMATITIS 1) Treat mild mucositis with bland oral rinses with 0.9% saline, sodium bicarbonate, and water. For moderate cases with pain, consider adding a topical anesthetic (eg, lidocaine, benzocaine, dyclonine, diphenhydramine, or doxepin). Treat moderate to severe mucositis with topical anesthetics and systemic analgesics (eg, morphine, hydrocodone, oxycodone, fentanyl). Patients with mucositis and moderate xerostomia may receive sialagogues (eg, sugarless candy/mints, pilocarpine/cevimeline, or bethanechol) and topical fluorides to stimulate salivary gland function. Patients who are receiving myelosuppressive therapy may receive prophylactic antiviral and antifungal agents to prevent infections. Topical oral antimicrobial mouthwashes, rinses, pastilles, or lozenges may be used to decrease the risk of infection (Bensinger et al, 2008). 2) Palifermin is indicated to reduce the incidence and duration of severe oral mucositis in patients with hematologic malignancies receiving myelotoxic therapy requiring hematopoietic stem cell support. In these patients, palifermin is administered before and after chemotherapy. DOSES: 60 mcg/kg/day IV bolus injection for 3 consecutive days before and 3 consecutive days after myelotoxic therapy for a total of 6 doses. Palifermin should not be given within 24 hours before, during infusion, or within 24 hours after administration of myelotoxic chemotherapy, as this has been shown to increase the severity and duration of mucositis. (Hensley et al, 2009; Prod Info KEPIVANCE(TM) IV injection, 2005). In patients with a lenvatinib overdose, administer palifermin 60 mcg/kg/day IV bolus injection starting 24 hours after the overdose for 3 consecutive days. 3) Total parenteral nutrition may provide nutritional requirements during the healing phase of drug-induced oral ulceration, mucositis, and esophagitis.
E) HYPERTENSIVE EPISODE 1) 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. 2) 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. 3) 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.
4) 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).
5) 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).
6) 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).
7) 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).
8) NITROGLYCERIN/INDICATIONS a) May be used to control hypertension, and is particularly useful in patients with acute coronary syndromes or acute pulmonary edema (Rhoney & Peacock, 2009).
9) NITROGLYCERIN/ADULT DOSE a) Begin infusion at 10 to 20 mcg/min and increase by 5 or 10 mcg/min every 5 to 10 minutes until the desired hemodynamic response is achieved (American Heart Association, 2005). Maximum rate 200 mcg/min (Rhoney & Peacock, 2009).
10) NITROGLYCERIN/PEDIATRIC DOSE a) Usual Dose: 29 days or Older: 1 to 5 mcg/kg/min continuous IV infusion. Maximum 60 mcg/kg/min (Laitinen et al, 1997; Nam et al, 1989; Rasch & Lancaster, 1987; Ilbawi et al, 1985; Friedman & George, 1985).
11) 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).
12) 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).
13) 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).
14) 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).
15) 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).
16) 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).
F) 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).
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