Interactions between abarelix and Quinidine (quinidine)
quinidine and abarelix (Major Drug-Drug)
GENERALLY AVOID: Use of abarelix may cause prolongation of the QT interval in some patients. Theoretically, coadministration with other agents that can prolong the QT interval may result in elevated risk of ventricular arrhythmias, including ventricular tachycardia and torsade de pointes, because of additive arrhythmogenic potential related to their effects on cardiac conduction. In a single, active-controlled, clinical study comparing abarelix to LHRH (luteinizing hormone releasing hormone) agonist plus nonsteroidal antiandrogen therapy, both therapies were found to prolong the mean Fridericia-corrected QT interval by more than 10 msec from baseline. In approximately 20% of patients in both groups, there were either changes from baseline QTc of greater than 30 msec or end-of-treatment QTc values exceeding 450 msec. Similar results were observed in two other Phase 3 studies with abarelix and the active-control treatments. It is unclear whether these changes were directly related to study drugs, to androgen deprivation therapy, or to other variables.
MANAGEMENT: The concurrent use of abarelix with class IA (e.g., disopyramide, quinidine, procainamide) and class III (e.g., amiodarone, dofetilide, sotalol) antiarrhythmic agents should preferably be avoided unless benefits are anticipated to outweigh the risks.
