Major
Dronedarone × Simvastatin
Class III antiarrhythmic×HMG-CoA reductase inhibitors (statins)
Mechanism
Dronedarone inhibits CYP3A4 – the main simvastatin metabolic route. Simvastatin plasma levels rise 4-fold. FDA Zocor 2012 caps simvastatin at 10 mg/day with dronedarone.
Symptoms
Pain and weakness in large muscle groups (thighs, shoulders, calves), dark urine, elevated creatine kinase. Severe cases progress to rhabdomyolysis with acute kidney injury. Symptoms appear within 1–4 weeks of co-administration.
Management
Cap simvastatin at 10 mg/day when combined. If LDL targets are missed, switch to pravastatin or rosuvastatin (no CYP3A4 dependence).
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.