amiodarone + bisoprolol + digoxin

This is a combination therapy consisting of three drugs—amiodarone, bisoprolol, and digoxin—used primarily in the management of cardiac arrhythmias such as atrial fibrillation (AF) and heart failure. - **Amiodarone** is a class III antiarrhythmic agent that works by blocking potassium channels, thereby prolonging repolarization and refractory period in cardiac tissue. It also has effects on sodium and calcium channels as well as noncompetitive beta-adrenergic blocking activity[8][7]. - **Bisoprolol** is a selective beta-1 adrenergic receptor blocker (beta-blocker) that reduces heart rate, myocardial contractility, and AV nodal conduction[7]. - **Digoxin** is a cardiac glycoside that inhibits the sodium-potassium ATPase pump in myocardial cells, leading to increased intracellular calcium concentrations; this enhances contractility (positive inotropy) and slows AV nodal conduction (negative chronotropy)[6][7]. The combination may be used for rhythm or rate control strategies in AF or for symptomatic management of heart failure when monotherapy does not achieve adequate control. However, combining these agents increases the risk of drug-drug interactions—most notably amiodarone can increase serum digoxin levels by inhibiting P-glycoprotein-mediated elimination pathways[5], raising the risk for digoxin toxicity. Clinical studies have shown increased all-cause mortality with certain combinations such as amiodarone plus digoxin compared to digoxin alone[1]. The use of all three together should be carefully monitored due to additive effects on bradycardia, AV block, proarrhythmia risk, and potential toxicity.