Ivabradine, a novel treatment for clozapine-induced sinus tachycardia: a case series.

Abstract

Clozapine is the most efficacious treatment for treatment-resistant schizophrenia; however its use can be limited by intolerability. Sinus tachycardia is a common adverse event associated with clozapine use, which may lead to the premature discontinuation of clozapine. Traditionally, β blockers are used to treat clozapine-associated tachycardia, though problems with intolerability and ineffectiveness can limit their utility. In this article, we present two cases of patients with treatment-resistant schizophrenia who developed symptomatic tachycardia associated with clozapine therapy. We demonstrate that the novel heart rate controlling agent ivabradine can be effectively and safely used to control the heart rate and to allow for continued treatment with clozapine. This is the first report in the literature demonstrating that ivabradine appears to be a well tolerated agent, which should be considered as a symptomatic treatment of clozapine-induced tachycardia if the use of a β blocker fails due to a lack of response or intolerability.