Bisoprolol × Verapamil

Beta-blocker (bisoprolol) and non-dihydropyridine calcium channel blocker (verapamil) additively depress AV conduction and myocardial contractility. High risk of bradycardia, AV block, and heart failure decompensation.

Bradycardia (heart rate below 50/min), dizziness, syncope. ECG: second- to third-degree AV block. Drop in ejection fraction with dyspnoea and oedema in heart failure patients.

Avoid the combination. For atrial fibrillation rate control, choose bisoprolol plus digoxin (instead of verapamil), or verapamil with bisoprolol withdrawn. Diltiazem is also not combined with a beta-blocker.