Using data from three US Medicaid programmes, researchers compared the frequency of cardiac events among patients with treated schizophrenia and control patients with psoriasis or glaucoma. They also compared the cardiac risk of different antipsychotic drugs (thioridazine, haloperidol, risperidone, and clozapine).
They found that patients with treated schizophrenia had higher rates of cardiac events than controls.
Overall, the risk with thioridazine was no worse than that with haloperidol. Thioridazine may carry a greater risk than haloperidol at high doses, although this finding could be due to chance, say the authors.
To reduce cardiac risk, patients requiring thioridazine should be treated with the lowest dose possible to treat their symptoms, they conclude.