Hostility and hallucinations as a consequence of midazolam administration.

A 74-year-old woman experienced an apparent psychotic reaction several hours after administration of iv midazolam as a premedicant for gastroscopy. The reaction included confusion, hallucinations, and hostility and required administration of haloperidol to calm her. The woman subsequently underwent colonoscopy with meperidine as a premedication and experienced no behavioral changes. Although other causes cannot be completely ruled out, the evidence points strongly to midazolam as the precipitating agent for the psychotic reaction.