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VARIOUS › ALL OTHER THERAPEUTIC PRODUCTS › ALL OTHER THERAPEUTIC PRODUCTS › Antidotes
physostigmine
V03AB19
Forms & Strengths
- Injection: 1 mg/mL in 2 mL ampoules
Adult Dosing
- Anticholinergic toxicity: Initial 2 mg IV slowly at a rate not exceeding 1 mg/min
- Repeat dose: 1 to 4 mg IV every 20 to 30 minutes if life-threatening symptoms recur
Pediatric Dosing
- Anticholinergic toxicity: Initial 0.02 mg/kg IV slowly over at least 5 minutes
- Maximum single dose: 0.5 mg
- Repeat dose: May repeat every 5 to 10 minutes up to a maximum total dose of 2 mg if toxic effects persist
Indications
- Reversal of central and peripheral anticholinergic toxicity (e.g., atropine, scopolamine, tricyclic antidepressants)
Mechanism of Action
- Reversible acetylcholinesterase inhibitor that inhibits the destruction of acetylcholine at synaptic clefts
- Crosses the blood-brain barrier to reverse both central and peripheral anticholinergic manifestations
Contraindications
- Asthma
- Gangrene
- Diabetes mellitus
- Cardiovascular disease
- Mechanical obstruction of the intestinal or genitourinary tract
- Concurrent use of depolarizing neuromuscular blocking agents
- Tricyclic antidepressant overdose with widened QRS complex or ventricular conduction abnormalities
Adverse Reactions
- Bradycardia
- Asystole
- Hypotension
- Excessive salivation
- Emesis
- Sweating
- Seizures (with rapid administration)
- Bronchospasm
- Muscle fasciculations and weakness
Drug Interactions
- Succinylcholine and other depolarizing neuromuscular blockers: synergistic effects leading to prolonged apnea
- Beta-blockers: risk of severe bradycardia and asystole
- Cholinesterase inhibitors: additive toxicity
- Anticholinergics: direct pharmacologic antagonism
Curated Content: Needs Vetting Before Put to Clinical Use