Tardive dyskinesia uncovered after ingestion of Sominex, an over-the-counter drug.

Ingestion of an over-the-counter preparation of diphenhydramine (Sominex), an anticholinergic antihistamine, induced a dramatic uncovering of generalized tardive dyskinesia in an outpatient on chronic neuroleptic therapy. Failure to obtain a detailed medication history, including that of non-prescription drugs, may lead to incorrect diagnosis and management.