Thioridazine and sudden unexplained death in psychiatric in-patients.

<bold>Background: </bold>Sudden death has been linked to antipsychotic therapy, but the relative risk associated with specific drugs is unknown.<bold>Aims: </bold>To assess the risk of sudden unexplained death associated with antipsychotic drug therapy and its relation to drug dose and individual agents.<bold>Method: </bold>A case-control study of psychiatric in-patients dying suddenly in five hospitals in the north-east of England and surviving controls matched for age, gender and mental disorder. Logistic regression analysis was used to identify significant risk factors, and odds ratios were calculated.<bold>Results: </bold>Sixty-nine case-control clusters were identified. Probable sudden unexplained death was significantly associated with hypertension, ischaemic heart disease and current treatment with thioridazine (adjusted odds ratio=5.3, 95% CI 1.7-16.2, P=0.004). There was no significant association with other individual antipsychotic drugs.<bold>Conclusions: </bold>Thioridazine alone was associated with sudden unexplained death, the likely mechanism being drug-induced arrhythmia. [ABSTRACT FROM AUTHOR]