Category:

• Nervous system

Description:

• Anticholinesterase antidote

Indications:

• Antidote in poisonings due to organophosphate pesticides and related compounds

• Control of overdose by anticholinesterase drugs used to treat myasthenia gravis

Precautions:

• Pregnancy category C

• Rapid IV injection, impaired renal function

• Myasthenia gravis, carbamate poisoning (less effective than with organophosphate poisoning)

Adverse Reactions (Side Effects):

• CNS: dizziness, drowsiness, headache

• CV: tachycardia

• EENT: blurred vision, diplopia, impaired accommodation

• GI: transaminase elevations, nausea

• MS: muscular weakness

• RESP: hyperventilation

• SKIN: pain at injection site (IM)

Dosage:

Administered intramuscularly, intravenously

• Adult:            

  • Organophosphate poisoning: 

    • IM/IV 1-2g, repeat in 1-2 hours if muscle weakness has not resolved, then at 10-12 hour intervals in cholinergic signs reappear

  • Anticholinesterase overdose: 

    • IV 1-2g followed by 250mg every 5 minutes until desired response

• Child:            

  • Organophosphate poisoning: 

    • IM/IV 20-50 mg/kg/dose, repeat in 1-2 hours if muscle weakness has not resolved, then at 10-12 hour intervals if cholinergic signs reappear