Physostigmine
We recommend 1-2 mg (0.05 mg/kg, maximum initial dose of 0.5 mg in children) IV slow infusion over at least 5 minutes to reduce the risk of seizures. Dose may be repeated for incomplete response after 5 to 10 minutes up to a maximum of 2 mg in children and 4 mg in adults. Always have atropine and a benzodiazepine at bedside in case of significant cholinergic excess symptoms or seizures, respectively. Response to physostigmine can occur rapidly (within minutes), but the duration of effect of physostigmine tends to be shorter than that of antimuscarinic agents. Observe for recurrence of antimuscarinic symptoms, and assess if the patient will need repeated dosing of physostigmine.
