Major
Amiodarone × diltiazem
Class III antiarrhythmics (Vaughan Williams)×Calcium channel blocker, non-DHP (benzothiazepine derivative)
Mechanism
Additive bradycardia and AV block. Third-degree AV block with syncope has been reported. Both drugs slow AV nodal conduction.
Symptoms
Bradycardia (heart rate below 50/min), dizziness, syncope. ECG: first- to second-degree AV block. Older patients: fall risk.
Management
Avoid the combination. In atrial fibrillation, choose one strategy: amiodarone for rhythm control, diltiazem for rate control. Alternatives: a beta-blocker + digoxin or catheter ablation.
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.