Major
Amlodipine × Dronedarone
Calcium channel blockers (dihydropyridines)×Class III antiarrhythmic
Mechanism
Dronedarone is a strong CYP3A4 inhibitor, the main amlodipine metabolic route. Amlodipine plasma levels may double.
Symptoms
Blood pressure drop: postural dizziness, syncope. Ankle oedema (typical of amlodipine), facial flushing, reflex tachycardia are possible.
Management
Cap amlodipine at 5 mg/day when combined. Alternative calcium channel blocker: diltiazem (with caution combined with an antiarrhythmic), or replace amlodipine with an ACE-I/ARB.
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.