Ivabradine Use for Arrhythmias in Children

Ivabradine is a hyperpolarization-activated cyclic nucleotide-gated channel blocker that has an off-label indication for arrhythmias in pediatric patients.

The primary objective was identification of the line of therapy and type of arrhythmia for which ivabradine was initiated. The secondary objective was to evaluate the initial and peak ivabradine doses, tolerance in partially fed patients (i.e., patients not receiving full feeds at the time of ivabradine initiation), number of patients continued home on ivabradine, concomitant drug interactions with a class C, D, or X classification, and adverse effects.

A retrospective study of hospitalized patients <18 years of age receiving ivabradine for arrhythmias between January 1, 2021 and November 30, 2023. Data variables included demographics, ivabradine dosing regimens, concomitant anti-arrhythmic medications, percentage of ivabradine course while receiving full enteral feeds, concomitant medications with drug-drug interactions, and adverse effects (bradycardia [defined as <100 beats/min in neonates and <50 beats/min in infants and children], atrial fibrillation, vision changes, and emesis attributed to ivabradine).

Seventeen patients were included. The most frequent arrhythmia indication was atrial tachycardia and ivabradine was most frequently used as a third-line anti-arrhythmic. Ten (58.8%) received ivabradine despite not being on full enteral feeds. The median initial and peak ivabradine doses were 0.05 mg/kg/dose and 0.07 mg/kg/dose, respectively, and it was most frequently administered every 12 hours. Only 1 patient required a dose decrease for a noted adverse effect. Most patients (94.1%) had a Class C drug-drug interaction, and 3 had a Class X interaction. Ten (58.8%) were discharged home on ivabradine.

Ivabradine was safe and effective as additive therapy for the treatment of pediatric arrhythmias. Larger studies of ivabradine use in pediatric arrhythmias are needed.