Physostigmine

Indications

Physostigmine is used for: Reversal of anticholinergic effect, Stimulate peristalsis in postoperative intestinal atony

Adult Dose

Parenteral Reversal of anticholinergic effect Adult: Initial dose: 0.5-2 mg. May be given via slow IV inj or IM, repeated every 20 min until response or adverse effects occur. If initial doses are effective, additional doses of 1-4 mg may be given as necessary at usual intervals of 30-60 minutes as life-threatening signs recur. Stimulate peristalsis in postoperative intestinal atony Adult: Usual dose: 0.5-2 mg IV or IM inj.

Child Dose

Parenteral Reversal of anticholinergic effect Child: For life-threatening situations only: 0.02 mg/kg as initial dose. May be given via slow IV inj or IM, repeated at 5-10 min intervals until response or adverse effects occur or a total dose of 2 mg has been admin.

Renal Dose

Administration

Contra Indications

Salicylate allergy Asthma, gangrene, diabetes, cardiovascular disease, mechanical obstruction of the intestinal or urogenital tract or any vagotonic state Concurrency with choline esters or depolarizing neuromuscular blocking agents

Precautions

Keep atropine ready for potential cholinergic sx

Pregnancy-Lactation

Pregnancy Category: C Lacation: Unknown if excreted in breast milk; caution advised

Interactions

Aminoglycosides, clindamycin, colistin, cyclopropane, halogenated inhalational anaesthetics and atropine may antagonise the effects of physotigmine. Quinine, chloroquine, hydroxychloroquine, quinidine, procainamide, propafenone, lithium and β-blockers may reduce treatment efficacy. Prolonged bradycardia may occur when taken with β-blockers. May prolong the action of suxamethonium when used together.

Adverse Effects

Side effects of Physostigmine : Frequency Not Defined Seizure Cardiovascular collapse Bradycardia Bronchospasm Dyspnea Diaphoresis Diarrhea Hyperperistalsis Cholinergic Sx Hallucinations

Mechanism of Action

Physostigmine is a reversible tertiary amine cholinesterase inhibitor, prolongs and intensifies physiological actions of acetylcholine.