Thioridazine and sudden unexplained death in psychiatric in-patients

Background Sudden death has been linked to antipsychotic therapy, but the relative risk associated with specific drugs is unknown. Aims To assess the risk of sudden unexplained death associated with antipsychotic drug therapy and its relation to drug dose and individual agents. Background Sudden death has been linked to antipsychotic therapy, but the relative risk associated with specific drugs is unknown. Method 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. Results 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% Cl 1.7-16.2, P=0.004). There was no significant association with other individual antipsychotic drugs. Conclusions Thioridazine alone was associated with sudden unexplained death, the likely mechanism being drug-induced arrythmia.