Amantadine toxicity presenting with complex ventricular ectopy and hallucinations

Amantadine hydrochloride is a commonly prescribed drug with a narrow therapeutic-to-toxic range. Toxicity is related to the anticholinergic properties of the drug and primarily affects the cardiovascular, central nervous, and respiratory systems. We report the case of an adolescent who ingested 1.3 grams of amantadine and developed complex ventricular arrhythmias and altered mental status. The arrhythmias were completely suppressed with intravenous lidocaine. This case supports the hypothesis that lidocaine is effective for treatment of ventricular arrhythmias secondary to amantadine toxicity.