flecainide + verapamil

Flecainide + verapamil is a combination of two antiarrhythmic agents used together primarily in the management of certain cardiac arrhythmias, such as atrial fibrillation. Flecainide is a class IC antiarrhythmic that works by blocking sodium channels (Sodium channel protein type 5 subunit alpha), thereby slowing conduction in cardiac tissue and stabilizing abnormal electrical activity. Verapamil is a non-dihydropyridine calcium channel blocker (L-type calcium channel) that inhibits calcium influx into myocardial and vascular smooth muscle cells, leading to decreased heart rate and contractility, as well as slowed atrioventricular nodal conduction. The combination has additive effects on myocardial contractility and atrioventricular conduction[2][3]. Clinical studies suggest that adding verapamil to flecainide can reduce recurrences of atrial fibrillation after cardioversion[4][7]. However, this combination increases the risk of adverse effects such as bradycardia, hypotension, or heart block due to their overlapping actions on cardiac conduction; thus it should be used with caution under specialist supervision[1][6].