Moderate
Atorvastatin × Dronedarone
HMG-CoA reductase inhibitors (statins)×Class III antiarrhythmic
Mechanism
Dronedarone blocks CYP3A4 – a partial atorvastatin metabolic route. Atorvastatin plasma levels rise 2-fold, raising myalgia risk.
Symptoms
Pain and weakness in large muscle groups (thighs, shoulders, calves), dark urine, elevated creatine kinase. Symptoms usually appear 2–6 weeks after starting the combination.
Management
Cap atorvastatin at 20 mg/day when combined. If LDL targets are missed, switch to pravastatin or rosuvastatin (no CYP3A4 dependence).