Ivabradine exposures reported to United States poison centers 2015-2023

Ivabradine was approved for use in the United States in 2015 for the management of heart failure. It acts through inhibition of sodium channels found in cardiac myocytes (the "funny" pacemaker current, I_f), which reduces heart rate without significantly affecting inotropy.

We queried the National Poison Data System^® for reported ivabradine exposures from April 15, 2015-December 31, 2023. Age was stratified into child (0-5 years), adolescent (6-17 years), adult (18-64 years) and geriatric (65+ years). Other descriptive statistics gathered included patient sex, management site, and medical outcome as coded by America's Poison Centers^®.

There were 240 ivabradine exposures, with 55.0% managed on-site and not transferred to a healthcare facility. The most common reported symptom was bradycardia, reported in 36 patients (15.1%). There were 139 cases that were followed to a known outcome. Within this cohort, 60%, 14%, and 27% of patients suffered no effect, minor effect, or moderate effect, respectively. Exposures in children comprised 18.8% of cases; none required intervention. Intentional self-harm exposures comprised 17.1% of all cases and were more likely to have worse outcomes. Five adult patients received intensive therapy (endotracheal intubation, vasopressors, cardiac pacing, hemodialysis). There were no reported deaths from ivabradine exposure.

This study has limitations. First, our data source was limited by being retrospective and incomplete; we could only study the information that was reported to poison centers, and exposures were not confirmed by laboratory testing. It is possible that cases without further follow-up had other treatments and clinical effects not reported here. Finally, reports to poison centers likely underestimate the true number of ivabradine exposures.

Adults with unintentional, asymptomatic exposures to ivabradine may be candidates for home monitoring. In ivabradine exposures refractory to medical management, clinicians should consider cardiac pacing or other supportive measures as a temporizing measure.