What to do: Patients should be warned of these uncommon but potentially fatal cardiovascular adverse effects associated with clozapine. Before treatment, a cardiac evaluation should be considered for patients with a personal or family history of heart disease; clozapine is contraindicated in patients with severe cardiac disease. Although patients are at greatest risk in the first month of therapy, the risk may persist as long as they are taking the drug. Clinicians caring for schizophrenic patients who are taking clozapine should maintain a high degree of suspicion if signs or symptoms consistent with cardiac toxicity develop (see side box). The drug should promptly and permanently be stopped in patients with myocarditis; discontinuation of the drug should be considered in patients with cardiomyopathy. Bayesian analyses of data from several international adverse reaction databases suggest that other antipsychotic drugs may also be associated with episodes of myocarditis or cardiomyopathy, but not to the same degree as clozapine.10