Clozapine-induced myocarditis during co-administration of valproate: A case report

Clozapine, atypical antipsychotic drug, is widely used in patients with schizophrenia, for whom previous therapy was inadequate or not tolerated. Clozapine-induced myocarditis (CIM) is a relatively rare but potentially life-threatening complication of clozapine therapy; however, the underlying mechanism has not been so far well elucidated. Factors predisposing to CIM include a rapid dose titration, advanced age and co-administration of sodium valproate. In this paper, we present a case of a 22-year-old male patient with refractory schizophrenia who developed CIMduring low-dose clozapine treatment with co-administration of valproate and risperidone. On the basis of our case and literature review, we point out that during the first weeks of clozapine treatment patients should be actively, daily monitored for the presence of symptoms suggesting CIM. The low dose of clozapine and concurrent use of valproate are unique aspects of the report, adding new information to the discussion on safety of concomitant use of clozapine and valproate. Further investigation is required to better understand the role of co-administration of valproate and risperidone in the pathogenesis of CIM.