Simvastatin and Amiodarone Linked to Possibly Fatal Muscle DiseaseAug 8, 2008 | Parker Waichman LLP
Combination of Simvastatin and Amiodarone, an Anti-Arrhythmia Medication
The combination of simvastatin and amiodarone, an anti-arrhythmia medication, has been linked to a rare muscle condition that can cause kidney damage and death. The Food & Drug Administration (FDA) first warned against combining the drugs in 2002 because of their association with the condition - called rhabdomyolysis - but has continued to received reports of its occurrence.
Amiodarone is an ingredient in Wyeth's Cordarone and is also sold generically. Simvastatin is an ingredient in Merck & Co's Zocor and Abbott Laboratories Inc's Simcor, and is sold generically. It also a component of Merck and Schering-Plough Corp's Vytorin.
Simvastatin is a statin, a class of drugs which already carries a risk of rhabdomyolysis. However, the FDA said today that the risk of developing rhabdomyolysis is more pronounced when simvastatin is combined with amiodarone than it is with other statin medications.
Rhabdomyolysis is Muscle Injury that Causes the Rapid Breakdown
Rhabdomyolysis is a muscle injury that causes the rapid breakdown of skeletal muscle tissue. The destruction of the muscle leads to the release of the breakdown products of damaged muscle cells into the bloodstream; some of these, such as myoglobin, are harmful to the kidney and may lead to acute kidney failure.
According to today's FDA warning, the risk of developing rhabdomyolysis is dose-related and increases when a dose of simvastatin greater than 20 mg per day is given with amiodarone. The agency said that healthcare professionals, who prescribe simvastatin or simvastatin-containing medications (Simcor, Zocor, Vytorin), should be aware that patients taking amiodarone should not take more than 20 mg per day of simvastatin.
Patients starting therapy with simvastatin, or who have had their dose of simvastatin increased, should contact their doctor immediately if they experience symptoms of unexplained muscle injury, such as muscle cramps, pain, tenderness, stiffness or spasm.
The FDA said it is working with the manufacturer of Cordarone (amiodarone) to modify prescribing information to warn of an increased risk of rhabdomyolysis when amiodarone is taken with simvastatin doses exceeding 20 mg daily. In 2002, the labeling of simvastatin was changed to include similar information.