Bupropion (amfebutamone) is a monocyclic antidepressant pharmacologically unrelated to the other antidepressant classes, with structural similarities to amphetamine and diethylpropion. Bupropion is indicated in the treatment of depression and as an aide to smoking cessation. In addition, bupropion has reportedly been used in the treatment of chronic fatigue syndrome and Crohn's disease, with equivocal results. In bupropion overdose, toxicity is primarily neurological, with agitation, hallucinations, tremor, and seizures. Cardiovascular toxicity has been primarily sinus tachycardia, with some reports of Qtc prolongation and sodium channel blockade evidenced by QRS widening. Death after bupropion ingestion is rare, but has been reported. Nausea and vomiting have been noted in burpropion overdose, which occurred in four of the five cases discussed. Sustained release formulation bupropion may produce delayed onset of severe clinical effects, despite an early asymptomatic period. Sustained release formulation bupropion may release significant portions of drug for absorption while retaining a recognizable pill body shell in the stomach and intestines. Four patients had ingested a sustained-release formulation of bupropion and had evidence of pill "bodies" in their stomach, with significantly elevated blood bupropion concentrations. The pills found in these patients may represent the residual matrix/shell with significant potions of the actual bupropion released and absorbed by the patients. 15 references