Oral Ondansetron Tied With Sudden Cardiac Death in Dialysis Patients – Renal and Urology News

Oral ondansetron increases the risk of sudden cardiac death among patients receiving maintenance hemodialysis, a new study finds.

In a study of 119,254 patients in the 2012-2019 US Renal Data System, 64,978 patients (54.5%) initiated oral ondansetron, and 54,276 (45.5%) initiated a comparator oral antiemetic (promethazine, metoclopramide or prochlorperazine).

The risk for sudden cardiac death within 10 days was a significant 44% higher among patients receiving ondansetron rather than another antiemetic, Jennifer E. Flythe, MD, MPH, of the University of North Carolina Kidney Center at Chapel Hill, and colleagues reported in the Journal of the American Society of Nephrology. The number needed to harm was 1688 patients. The results applied to adults younger than 65 years and patients without heart failure.

Intravenous ondansetron is known to prolong the QT interval and carries a risk of torsades de pointes, but less is known about the oral formulation, the investigators pointed out. The drug label urges electrocardiogram monitoring in patients with electrolyte abnormalities, heart failure, bradyarrhythmias, and concurrent use of other QT prolonging medications, all of which are common among the dialysis population. (Some other medications known to prolong the QT interval in this population, include escitalopram, citalopram, azithromycin, and respiratory fluoroquinolones.)

With respect to the alternate antiemetics, promethazine has a possible risk of torsades de pointes, and metoclopramide has a conditional risk. Prochlorperazine is not known to prolong the QT interval or have torsades de pointes risk.

According to Dr Flythe’s team, “clinicians should consider individual patient risk factors for arrhythmia such as extent of underlying structural heart disease, concomitant medications, and electrolyte profiles when making antiemetic prescribing decisions. In patients for whom the benefits of ondansetron prescription are perceived to outweigh the potential risks, clinicians should consider performing both baseline and monitoring electrocardiograms during the course of ondansetron therapy.”