Poisoning, Antidotes

Treatment

N-Acetylcysteine (NAC)
  • Indications: Acetaminophen overdose
  • Warnings:
    • Unpleasant odor, nausea, vomiting
    • Most effective if given in first 8 hr postingestion
  • Dose:
    • PO: 140 mg/kg, then 70 mg/kg q4h for 17 doses
    • IV (consult poison center): 150 mg/kg in 200 mL D5W over 60 min, then 50 mg/kg in 500 mL D5W over 4 hr, then 100 mg/kg in 1,000 mL D5W over 16 hr

Pediatric Considerations
This volume of D5W will need to be reduced in dosing pediatric patients to avoid fluid overload/hyponatremia. Discuss with pharmacy

Atropine
  • Indications:
    • Bradycardia owing to drugs
    • Organophosphate insecticides
  • Warnings:
    • Myasthenia gravis, narrow-angle glaucoma, HTN, coronary ischemia, and urinary obstruction
  • Dose:
    • Adult: 1–2 mg IV
    • Pediatric: 0.02 mg/kg (min 0.1 mg) IV
    • Large repeated doses needed in organophosphate poisoning
Benztropine (Cogentin)
  • Indications: Acute dystonic reactions
  • Warnings: Carbamates, myasthenia gravis, narrow-angle glaucoma, HTN, coronary ischemia, and urinary obstruction
  • Dose:
    • Adult: 1–2 mg IV (for acute reaction) or PO (to prevent reaction)
    • Pediatric: 0.02 mg/kg IV (for acute reaction) or PO (to prevent reaction)
Benzodiazepine
  • Indications: Agitation, stimulant drugs, seizures
  • Warnings: Respiratory/CNS depression
  • Dose:
    • Midazolam:
      • Adult: 1 mg IV/IM every 2–3 min p.r.n
      • Pediatric: 0.1 mg/kg IV/IM
    • Diazepam:
      • Adult: 2–5 mg IV/IM, repeat in 10–15 min
      • Pediatrics: 0.1 mg/kg IV/IM
Bicarbonate, Sodium
  • Indications: Cyclic antidepressant poisoning, metabolic acidosis, urinary alkalinization
  • Warnings: May cause CHF, excessive alkalosis, hypokalemia
  • Dose:
    • Serum alkalinization:
      • 1 mEq/kg IVP
    • Urine alkalinization:
      • 100–150 mEq in 1 L DW at 2–3 mL/kg/hr IV, goal urine pH 7–8
Black Widow Spider Antivenin (Lactrodectus Mactans)
  • Indications: Severe HTN, muscle spasms not alleviated by analgesics and muscle relaxants; consider in extremes of age (<5 or >65 yr), pregnant women with threatened abortion
  • Warnings:
    • Equine serum derived: Immediate hypersensitivity, serum sickness 10–14 d
    • Premedicate for anaphylaxis if known equine serum hypersensitivity
  • Dose: 1–2 vials IM/IV slowly over 15–30 min; dilute 1 vial in 50 mL saline for IV
Botulin Antitoxin Trivalent A, B, E
  • Indications: Clinical botulism, prior to onset of paralysis
  • Warnings:
    • Binds only free toxins
    • Not for infant botulism
    • Equine serum derived: Immediate hypersensitivity, serum sickness 10–14 d
    • Premedicate for anaphylaxis if known equine serum hypersensitivity
    • Administer slow IV push
  • Dose: 1–2 vials IV q4h for 4 or 5 doses; reconstitute 1 vial with 2 mL sterile water. Administer 0.5 mL/kg/hr IV. Double rate after 15 min if no ill effects
Calcium
  • Indications:
    • Hyperkalemia with cardiac toxicity
    • Hydrofluoric acid burn
    • Calcium channel blocker overdose
    • Citrate, oxalate, phosphate poisoning
  • Warnings:
    • Avoid in digoxin toxicity, hypercalcemia
    • Calcium chloride (CaCl) corrosive to skin, SC tissue
    • Incompatible with certain IV solutions
    • Administer slow IV push
  • Dose:
    • Adult: 5–10 mL of 10% CaCl, or 10–20 mL of 10% Ca gluconate
    • Pediatric: 0.1–0.2 mL/kg of 10% CaCl, or 0.2–0.3 mL/kg of 10% Ca gluconate
Calcium Edta (Edetate Disodium)
  • Indications: Lead, chromium, nickel, manganese, zinc toxicity
  • Warnings: Nausea, vomiting, chill, nephrotoxicity, hypercalcemia
  • Dose: 1 g/m2/d IV over 8–12 hr for 5 d, skip 2–4 d, then repeat. Follow lead (Pb) level
Coral Snake Antivenin (Micrurus Fulvius)
  • Indications: Eastern or Texas coral snake
  • Warnings:
    • Equine serum derived: Immediate hypersensitivity, serum sickness 10–14 d
    • Premedicate for anaphylaxis if known equine serum hypersensitivity
  • Dose: 4–10 vials slow IV push over 15–30 min
Cyanide Antidote KIT
  • Indications: Cyanide poisoning
  • Warnings: Hypotension, methemoglobinemia
  • Dose:
    • Amyl nitrite: 1–2 amp crushed, inhaled
      • Use amyl nitrite only until IV access is established
    • Sodium nitrite:
      • Adult: 300 mg in 10 mL IV over 5 min
      • Pediatric: 0.3 mL/kg of 3% solution IV
    • Sodium thiosulfate:
      • Adult: 12.5 g IV, may repeat in 1 hr
      • Pediatric: 250 mg/kg IV
Cyanokit (Hydroxocobalamin)
  • Indications: Cyanide poisoning
  • Warnings: Erythema, HTN
  • Dose:
    • Adult: 70 mg/kg IV to max. 5 g over 15 min; may repeat a second 5-g dose depending on severity of poisoning and clinical response. Max. 10 g. Reconstitute each 2.5 g vial with 100 mL 0.9% NaCl
    • Pediatric: Safety and efficacy have not been established in children. Suggested initial dose: 70 mg/kg IV
Dantrolene
  • Indications:
    • Malignant hyperthermia
    • Neuroleptic malignant syndrome
    • Serotonin syndrome
    • Muscle rigidity
  • Warnings: Muscle weakness, respiratory depression, hepatitis
  • Dose: 1–2 mg/kg IV bolus, repeat q10–15min p.r.n, max. 10 mg/kg
Deferoxamine (Desferal)
  • Indications: Iron toxicity
  • Warnings:
    • Do not treat for >24 hr, risk for delayed adult respiratory distress syndrome (ARDS)
    • Hypotension if >15 mg/kg/hr, flushing, urticaria
  • Dose: 10–15 mg/kg/hr IV, may increase in severe iron (Fe) poisoning
Digoxin Antibody (Digibind)
  • Indications: Digoxin, digitoxin toxicity
  • Warnings:
    • Falsely elevated digoxin levels after use
    • Development of CHF/atrial fibrillation in patients requiring digoxin
  • Dose:
    • 1 vial (40 mg) binds 0.6 mg digoxin
    • Number of vials = digoxin level (ng/mL) × weight (kg)/100
    • Dose estimate: Acute overdose 10–20 vials, chronic overdose 4–6 vials
Dimercaprol (BAL)
  • Indications: Arsenic, gold, mercury, lead-induced encephalopathy
  • Warnings: Renal toxicity, fever, nausea, vomiting, urticaria, cholinergic symptoms
  • Dose:
    • 3 mg/kg deep IM q4h for 2 d, then q12h for 7 d; follow metal levels
    • For Pb level >100 mcg/dL: 4–5 mg/kg IM q4h until Pb <50 mcg/dL, in conjunction with EDTA
Diphenhydramine (Benadryl)
  • Indications: Antihistamine, acute dystonic reaction
  • Warnings: Sedation, excitation in children, anticholinergic symptoms
  • Dose:
    • Adult: 25–50 mg IV/IM/PO q4–6h
    • Pediatric: 0.5–1 mg/kg IV/IM/PO q4–6h
Dmsa (Succimer, Chemet)
  • Indications: Pediatric lead poisoning
  • Warnings:
    • Caution in renal impairment – urinary elimination
    • Nausea, vomiting, diarrhea
  • Dose: 10 mg/kg PO q8h for 5 d, then q12h for 14 d, then reassess blood lead levels
Epinephrine
  • Indications: Angioedema, anaphylaxis, acute asthma, spinal shock, β-blocker overdose
  • Warnings: Dysrhythmias, HTN, tremor, anxiety
  • Dose:
    • Hypotension/shock:
      • Adult: 1–4 mcg/min IV infusion
      • Pediatric: Start IV infusion at 0.1 mcg/kg/min
    • Anaphylaxis:
      • Adult: 0.3–0.5 mg IM/SC
      • Pediatric: 0.01 mg/kg IM/SC
Ethanol
  • Indications: Methanol or ethylene glycol toxicity
  • Warnings:
    • Disulfiram reaction, CNS sedation
    • Hypoglycemia in pediatric population
    • Increase dose during dialysis, for chronic alcoholics
  • Dose:
    • IV: 10 mL/kg load as 10% solution over 1 hr, then 1 mL/kg/hr maintenance
    • PO: 1.5 mL/kg as 100-proof solution, then 0.3 mL/kg/hr maintenance
    • Goal: Ethanol level of 100–150 mg/dL
Flumazenil (Romazicon)
  • Indications: Benzodiazepine overdose
  • Warnings:
    • Contraindicated in tricyclic antidepressant (TCA) overdose
    • Lowers seizure threshold
    • Induces benzodiazepine withdrawal
  • Dose:
    • Adult: 0.2 mg IV slow, repeat q2–3min to 1 mg max.
    • Pediatric: 0.01–0.05 mg/kg IV over 30 min–1 hr
Fomepizole (4-MP, Antizol)
  • Indications: Methanol or ethylene glycol toxicity
  • Warnings: Nausea, dizziness, headache
  • Dose: 15 mg/kg load IV, then 10 mg/kg q12h for 4 doses, then 15 mg/kg q12h
Glucagon
  • Indications:
    • β-Blocker or calcium channel blocker overdose with bradycardia/hypotension
    • Hypoglycemia
  • Warnings:
    • Nausea, vomiting, hyperglycemia
    • Hypotension from diluent (phenol containing)
  • Dose:
    • β-Blocker or calcium channel blocker overdose:
      • Adult: 5–10 mg IV over 1 min
      • Pediatric: 50 mcg/kg IV up to max. 10 mg IV over 1 min
    • Hypoglycemia:
      • Adult: 0.5–1 mg IM/IV/SC
      • Pediatric: 0.025–0.1 mg/kg IM/IV/SC (max. 1 mg per dose)
Insulin/Glucose
  • Indications:
    • Calcium channel blocker overdose with severe hypotension/symptomatic bradycardia refractory to other therapies
    • Hyperkalemia
  • Warnings:
    • Experimental therapy: Consult a poison control center/medical toxicologist
    • Follow serum glucose q15min for 1 hr after the first bolus or after any increase in dose, then q1h
  • Dose:
    • Bolus:
      • 0.5–1 U/kg regular insulin, followed by 25 g glucose (1 amp D50)
    • Maintenance:
      • Insulin 0.5 unit regular insulin per kg/hr, titrate to 1 unit regular insulin per kg/hr
      • Glucose D10 start at 100 mL/hr (10 g/hr) and titrate to keep glucose ≥100 mg/dL
Intralipids
  • Indications:
    • Cardiac arrest due to local anesthetic toxicity, most commonly bupivacaine; however, may be useful for other lipid-soluble drugs
  • Warnings:
    • Experimental therapy: Consult a poison control center/medical toxicologist
  • Dose:
    • Intralipid 20% bolus; 1.5 mL/kg over 1 min followed by infusion 0.25 mL/kg/min
    • Repeat bolus in 3–5 min if circulation not restored
Methylene Blue
  • Indications: Methemoglobinemia with dyspnea or >25%
  • Warnings: G6-PD deficiency
  • Dose: 1–2 mg/kg slow IV as 1% solution, repeat in 1 hr
Naloxone (Narcan)
  • Indications:
    • Opiate poisoning, empiric treatment of coma
  • Warnings:
    • Acute opiate withdrawal, severe agitation
  • Dose:
    • Adult: 0.4–2 mg IV/IM, repeat to 10 mg
    • Pediatric: 0.1 mg/kg IV/IM
Octreotide
  • Indications: Sulfonylurea overdose with hypoglycemia
  • Warnings: Use with caution in diabetic patients
  • Dose:
    • Adult: 50 mcg SC q6h
    • Pediatric: 4–5 mcg/kg/d SC div q6h
Oxygen, Hyperbaric
  • Indications: Carbon monoxide (CO) poisoning
  • Warnings:
    • Tympanic membrane (TM) perforation, seizures owing to oxygen toxicity
    • Difficulty monitoring patient
  • Dose: 100% oxygen at 2–3 atm
Penicillamine
  • Indications: Arsenic, copper, lead, mercury with/following BAL or EDTA
  • Warnings: Contraindicated in penicillin allergy, renal insufficiency
  • Dose:
    • Lead:
      • Adult: 250–500 mg per dose PO q8–12h
      • Pediatric: 25–40 mg/kg/d PO in 3 div doses
    • Arsenic: 100 mg/kg/d PO div in 4 doses for 5 d (max. 1 g/d)
    • Mercury:
      • Adult: 250 mg PO q.i.d
      • Pediatric: 20–30 mg/kg/d PO in 4 div doses
Phentolamine
  • Indications:
    • Hypertensive crisis: Stimulants, sympathomimetics, MAO–tyramine reaction, and extravasated pressors
    • Reversal of cocaine-mediated vasospasm
  • Warnings: HTN, tachycardia, dysrhythmias
  • Dose:
    • HTN:
      • Adult: 1–5 mg IV bolus
      • Pediatric: 0.02–0.1 mg/kg bolus
    • Extravasation:
      • Adult: 5 mg diluted in 10–15 mL saline SC
      • Pediatric: 0.1 mg/kg diluted in 10–15 mL saline SC
Physostigmine
  • Indications: Severe anticholinergic syndrome
  • Warnings: Contraindicated in TCA overdose
  • Dose:
    • Adult: 0.5–1 mg IV, repeat in 10 min p.r.n
    • Pediatric: 0.02 mg/kg IV, repeat in 10 min p.r.n
Pralidoxime (2-PAM, Protopam)
  • Indications:
    • Organophosphate toxicity
    • Reversal of nicotinic effects
    • Reactivates enzyme
    • Use in conjunction with atropine
  • Warnings:
    • Myasthenic crisis if myasthenia gravis
    • Nausea, headache, dizziness, laryngospasm, muscle rigidity
  • Dose:
    • Adult: 1–2 g IV in 100 mL NaCl over 15 min, repeat in 1 hr p.r.n, repeat in 6 hr if nicotinic symptoms return
    • Pediatrics: 25–50 mg/kg over 15 min, repeat in 1 hr p.r.n, repeat in 6 hr if nicotinic symptoms return
Protamine
  • Indications: Reversal of heparin anticoagulation
  • Warnings:
    • Hypersensitivity in patients with fish allergy
    • Avoid benzyl alcohol diluent in neonates
  • Dose:
    • 1 mg for each 100-unit heparin, 1/2 dose if 30–60 min; 1/4 dose if 2 hr after heparin bolus
    • 25–50 mg slow IV over 15 min. Initial dose should not be >50 mg
Pyridoxine (Vitamin B6)
  • Indications:
    • Isoniazid-induced seizures
    • Gyromitra mushroom
  • Warnings: None, nontoxic
  • Dose:
    • Isonicotinic acid hydrazide (INH)–induced seizures:
      • Unknown ingested amount: 5 g for adult or 1 g for pediatrics
      • Dose (mg) = amount INH ingested (mg)
      • Gyromitra: 25 mg/kg IV over 30 min–1 hr
Rattlesnake Antivenin (Crotaline)
  • Indications: Significant envenomation by Crotaline species: Rattlesnake, cottonmouth, water moccasin, pit viper
  • Warnings:
    • Ovine-derived products: Immediate hypersensitivity, serum sickness 10–14 d
    • Premedicate for anaphylaxis if we know the equine/ovine serum hypersensitivity
  • Dose:
    • Ovine derived (CroFab):
      • 4–6 vials slowly; may repeat dose of 4–6 vials if control of envenomation not achieved, then 2 vials q6h for 3 doses
      • Reconstitute each vial with 25 mL sterile water. Dilute in 250 mL 0.9% NaCl and infuse over 1 hr
Vitamin K (Phytonadione, Aqua Mephyton)
  • Indications: Reversal of coumadin anticoagulation
  • Warnings: Hypersensitivity from IV administration
  • Dose:
    • 2–10 mg SC/slow IV, may repeat in 8 hr
    • 2–10 mg PO, may repeat in 12–48 hr

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