Patients taking both amiodarone and simvastatin can safely take up to 20 mg daily of the cholesterol-lowering agent, the Food and Drug Administration said Dec. 15.
The announcement rescinds a prior FDA recommendation to limit simvastatin to no more than 10 mg daily in patients concurrently taking amiodarone. In a press statement, the FDA acknowledged that the action, imposed last June, was an error.
Amiodarone was mistakenly included in a list of drugs that potentiate simvastatin levels, according to the statement. Excess levels of simvastatin have been linked to an increased risk of myopathy, including rhabdomyolysis.
Emerging evidence linking high simvastatin levels with myopathy prompted the initial dose reduction, according to the agency. After reviewing this evidence, the FDA cut the maximum daily dose from 80 to 10 mg when taken concurrently with amiodarone, verapamil, and diltiazem. The agency now says, however, that amiodarone does not interact with simvastatin or any drug containing simvastatin.
"Unlike other interacting drugs, there were no pharmacokinetic or clinical trial data to support the simvastatin dose reduction approved with amiodarone. Therefore FDA has determined that the simvastatin dose limitation, when taken with amiodarone, should be restored to 20 mg."