Physostigmine: is there a role for this antidote in pediatric poisonings?

PURPOSE OF REVIEW: Ingestion of anticholinergic medications is common in pediatrics. Toxicity may result in symptoms such as severe agitation requiring physical restraint. Physostigmine, an antidote for anticholinergic poisoning, could be useful in this situation. Many physicians are hesitant to use physostigmine after case series suggested its use in tricyclic antidepressant overdose was associated with asystole. This paper reviews the anticholinergic toxidrome and pathophysiology, recent literature on the efficacy and toxicity of physostigmine, and its dosing, indications, and contraindications.

RECENT FINDINGS: Recent articles suggest that toxicity associated with physostigmine consists mostly of seizures and cardiac arrhythmia, and occurs when used in the absence of anticholinergic symptoms. Despite potential complications, physostigmine has been shown to be useful in cases of confirmed anticholinergic poisoning by controlling agitation and reversing delirium, and appears to be safer and more effective than benzodiazepines in this situation.

SUMMARY: In the proper clinical situation such as pure anticholinergic overdose with severe symptoms, physostigmine can be beneficial. The potential for side effects is not insignificant, and the antidote should be used with caution in any patient with unknown ingestions or those with cardiac conduction defects. More research is needed, especially involving children, before we will fully understand the indications and toxicities associated with physostigmine.