Management of cardiac adverse effects of clozapine

SUMMARY Clozapine remains the only evidence-based treatment for treatment-resistant schizophrenia, supported by guidelines from the National Institute for Health and Care Excellence (NICE) and other authorities. However, clozapine is still underutilised for treatment-resistant schizophrenia, despite its proven benefits, including reduced all-cause mortality. This is attributed mainly to its association with adverse effects, including cardiac adverse effects. This review focuses on the latter, with a detailed exploration of clozapine-induced myocarditis – a potentially fatal acute hypersensitivity reaction – and cardiomyopathy, tachycardia and conduction deficits. Among other things, we discuss their pathophysiology, diagnosis and management, with signposting to international diagnostic criteria and monitoring protocols.