Adverse drug reactions. An epidemiological study at psychiatric hospitals.

A drug monitoring system has been established at psychiatric university hospitals in Berlin, Goettingen, and Munich since 1979 in order to investigate adverse reactions to psychotropic drugs. This report describes the system and presents results obtained over 3 years. 504 randomly selected patients were observed by Intensive Drug Monitoring; 75% of them had an adverse drug reaction (ADR) during hospitalization that was assessed as possible, probable, or definite including all grades (I-III) of severity. 5,096 other patients were monitored by Organized Spontaneous Reporting during treatment with psychotropic drugs: ADRs were responsible for drug withdrawal (severity grade III) in about 10% of them. Parkinsonism, psychomotor disturbance, akathisia, delirium, oversedation and increased transaminases were the most frequent ADRs of this kind. The relative frequency of ADRs was calculated, and ADR-profiles established for drugs most frequently withdrawn. The impact of ADRs on ongoing therapy of patients was assessed. Reliable data obtained by drug monitoring systems can be expected to aid in therapeutic decisions in patients with special risks of side effects to psychotropic drugs.