Major
Bisoprolol × diltiazem
Selective beta-adrenergic blockers×Calcium channel blocker, non-DHP (benzothiazepine derivative)
Mechanism
Non-dihydropyridine calcium channel blocker (diltiazem) + beta-blocker (bisoprolol) – additive AV node blockade and negative inotropic effect.
Symptoms
Bradycardia (heart rate below 50/min), dizziness, syncope. ECG: first- to second-degree AV block. Older patients: fall risk.
Management
Avoid the combination. For atrial fibrillation rate control, choose bisoprolol + digoxin (without diltiazem) or diltiazem with bisoprolol withdrawn.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.