Clozapine-induced myocarditis may warrant cardiac monitoring protocol

Abstract Background: Myocarditis, or inflammation of the heart muscle, is a black box warning associated with the use of clozapine. Although the incidence of clozapine-induced myocarditis is only 0.015% to 1.2%, recent retrospective studies have found that up to 66% of clozapine patients develop nonspecific symptoms consistent with myocarditis. Because of the difficulty in distinguishing these symptoms (including fever, tachycardia, and fatigue) from clozapine dose titration, myocarditis may be difficult to recognize. If left undetected, the condition could be fatal. Patient Case: A 25-year-old Filipino male with a history of schizoaffective disorder, bipolar type, continued to endorse persistent and distressing command auditory and visual hallucinations despite therapy with olanzapine, 40 mg daily. Clozapine was initiated for refractory psychosis and titrated up to 125 mg over 17 days. On day 14, the patient reported “feeling sick,” having chills, a nonproductive cough, and fatigue; he was febrile and ta...