Catatonic reaction to accidental haloperidol overdose: an unrecognized drug abuse risk.

A case is reported in which a patient was hospitalized with a severe mixed extrapyramidal symptoms-catatonic reaction after ingestion of three 10-mg tablets of haloperidol that he had purchased on the street, believing them to be Valium and intending to "get high." The diagnosis was initially missed because the patient and family reported no history of neuroleptic treatment. The syndrome resolved quickly with supportive care. Clinicians must consider this possibly underrecognized syndrome in patients presenting with sudden onset of parkinsonian and catatonic symptoms, particularly when substance abuse may have occurred.