Abstract 12650: A Faster and Safe Way for Dose Escalation of Sotalol Therapy in Patients With Atrial Fibrillation or Flutter

Abstract

Sotalol is frequently employed to prevent the recurrence of highly symptomatic atrial fibrillation or flutter, but recurrence is not unusual and may require dose escalation. Sotalol can cause QTc prolongation proportional to blood concentration and at times may cause Torsade de Pointes ventricular tachycardia (TdP). Because the risk of TdP, dose escalation of oral sotalol therapy is mandated by FDA to be in-hospital for a minimum of 3 days under ECG monitoring with facilities and personnel able to provide cardiac resuscitation. With oral administration (bid), 3 days are needed to reach the new maximal steady-state blood concentrations (Cmax ss) and thus maximal QTc . Three hospital days in a telemetry bed is costly of time and resources. IV sotalol makes it possible to reduce the escalation time from 3 days to 1 day. The IV to oral dose escalation has been developed by model informed drug development. Serum sotalol concentrations and corresponding QTc were obtained from a bioequivalence study in healthy volunteers who received a single dose of oral and IV sotalol. NONMEM software package was used for population pharmacokinetic modeling and simulation. First Order Conditional Estimation method with Interaction (FOCE-INTER) was used for computation. We chose to administer IV sotalol over 1 hour to obtain the new Cmax ss target in a timeframe convenient for medical staff to supervise. Simulation for dose escalation from 80 to 120 mg bid is shown in the Figure; 75 mg IV sotalol is administered over 1 hour followed by 120 mg oral sotalol at 5 hours from start of infusion, then a second oral dose of 120 mg at 12 hours. One can target escalation from 120 to 160 mg by loading 90 mg IV over 1 hr followed by 160 mg oral dosing. Sotalol concentration will peak in 2-4 hours following each oral administration, thus in 21 hour there will be 3 sotalol peak concentrations. This permits evaluation of QTc response and risk of TdP all within a 1 day admission.