Physostigmine

General

• Type: acetylcholinesterase inhibitor
• Dosage Forms: IV/IM
• Common Trade Names: Antilirium
• As opposed to pyridostigmine, physostigmine does cross the blood brain barrier

Adult Dosing

Anticholinergic toxicity

• 0.5-2 mg IV over 5 min

Non-depolarizing neuromuscular blockade reversal

• 0.5-1 mg IM/IV q10 min prn

Pediatric Dosing

• 0.02 mg/kg repeat every 5-10 minutes until adequate response, max of 2 mg
• No faster than 0.5 mg/min

Special Populations

• Pregnancy Rating: C
• Lactation:
• Renal Dosing
  • Adult
  • Pediatric
• Hepatic Dosing
  • Adult
  • Pediatric

Contraindications

• Allergy to class/drug
• TCA toxicity
  • Can cause asystole

Adverse Reactions

• Side effects: bradycardia, dysrhythmias, cholinergic excess
  • Always have atropine at the bedside for bradycardia or cholinergic excess

Pharmacology

• Reversible AChE inhibitor, that increases concentration of acetylcholine
• Indirectly stimulates both nicotinic and muscarinic ACh receptors
• Metabolism via CYP450
• Excretion minimally via urine
• Onset of action: 15-20min