Physostigmine adults

Doerr P, Berger M Physostigmine-induced escape from dexamethasone in normal adults. Biol Psychiatry 18 261-268, 1983... 

Physostigmine Suggested for antimuscarinic anticholinergic agents not for tricyclic antidepressants Adult dose is 0.5-1 mg IV slowly. The effects are transient (30-60 minutes), and the lowest effective dose may be repeated when symptoms return. May cause bradycardia, increased bronchial secretions, seizures. Have atropine ready to reverse excess effects. Do not use for tricyclic antidepressant overdose. 

Figure 1. Wing-beat frequency of Locusta adults before (arrow on abscissa) and after injection of 5 ul/g H O (Ar-A) or 5 yg/g physostigmine ( — ). Reproduced with permission from Ref. 29. Copyright 1973, Pergamon Press.

A small dose of physostigmine (see p 489), 0.5-1 mg IV in an adult, can be given to patients with severe toxicity (eg, hyperthermia, severe delirium, or tachycardia). Caution physostigmine can cause atrioventricular block, asystole, and seizures, especially in patients with tricyclic antidepressant overdose. 

A. Physostigmine. Parenteral 0.5-2 mg slow (<1 mg/min as adverse effects may be related to rapid administration) IV push (children, 0.02 mg/kg and given < 0.5 mg/min) while a cardiac monitor is used to monitor the patient repeat as needed every 10-30 minutes. Usual adult total dose is 4 mg. Atropine (see p 412) should be kept nearby to reverse excessive muscarinic stimulation and given at 1/2 the physostigmine dose (adults 1-4 mg children 1 mg). Do nof administer physostigmine intramuscularly or as a continuous intravenous infusion. 

B. The suggested minimum stocking level to treat a 70-kg adult for the first 24 hours is 10 ampules (2 ml each) for physostigmine and one 10-mL vial of 1 2000 or equivalent for neostigmine. 

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