Rifampicin administration (600 mg twice daily for 3 days) successfully overcame severe cardiogenic shock related to mavacamten toxicity, allowing normalization of plasma levels and patient recovery.
Case Report (n=1)
Does rifampicin improve cardiogenic shock related to mavacamten toxicity in a patient with HOCM?
Mavacamten toxicity and resulting cardiogenic shock due to drug interactions can be rapidly overcome by early administration of rifampicin, a strong hepatic enzyme inducer.
Abstract Background Mavacamten has shown to be efficient in the treatment of obstructive hypertrophic cardiomyopathy (HOCM). However, its use may be associated with toxicity and subsequent adverse events. CYP2C19 genotyping is therefore recommended to optimize dosing and minimize risks in daily practice. Case Summary We report here the case of a 39-years-old woman with history of sleeve gastrectomy and HOCM. She was initiated with mavacamten 5 mg once daily (CYP2C19 genotyping showed no mutation) because of persistent significant obstruction and dyspnea (NYHA class II) under nebivolol. Although initial tolerance was good with a reassuring transthoracic echocardiography at 4 months, she experienced 8 months later a severe cardiogenic shock related to mavacamten overdose in the context of esomeprazole initiation (proton pump inhibitor that strongly interacts with the cytochrome CYP2C19 and CYP3A4) for an esophageal pyrosis by her general practitioner. Noteworthy, the toxicity could be completely overcome by rifampicin initiation (600 mg twice daily for 3 days), which allowed normalization of plasma level of mavacamten within few days and patient recovery. Discussion The present case highlights that drug interactions in patients with HOCM receiving mavacamten are critical and may lead to high level of toxicity and severe heart failure events including cardiogenic shocks. Patient and care-giver information of these potential interactions is highly important. This case also emphasizes that dosage of mavacamten is now available (and should be used in specific situations) and that mavacamten toxicity can rapidly be overcome by early rifampicin administration, a strong hepatic enzyme inducer.
Lucas et al. (Tue,) conducted a case report in Cardiogenic shock related to mavacamten toxicity in HOCM (n=1). Rifampicin was evaluated on Patient recovery and normalization of plasma level of mavacamten. Rifampicin administration (600 mg twice daily for 3 days) successfully overcame severe cardiogenic shock related to mavacamten toxicity, allowing normalization of plasma levels and patient recovery.