Physostigmine is indicated to reverse the CNS effects caused by clinical or toxic dosages of agents capable of producing anticholinergic syndrome; however, long lasting reversal of anticholinergic signs and symptoms is generally not achieved because of the relatively short duration of action of physostigmine (45 to 60 minutes). It is most often used diagnostically to distinguish anticholinergic delirium from other causes of altered mental status. CAUTION: If tricyclic antidepressants are congested, physostigmine may precipitate seizures and dysrhythmias. DOSES: ADULT: 2 mg IV at a slow controlled rate, no more than 1 mg/min. May repeat doses at intervals of 10 to 30 min if severe symptoms recur. For patients with prolonged anticholinergic delirium consider a continuous infusion, start at 2 mg/hr and titrate to effect. CHILD: 0.02 mg/kg by slow IV injection, at a rate no more than 0.5 mg/minute. Repeat dosage at 5 to 10 minute intervals as long as the toxic effect persists and there is no sign of cholinergic effects. MAXIMUM DOSAGE: 2 mg total.