Merck’s simvastatin (Zocor) is in the news yet again. This time the FDA has revised the cholesterol-lowering drug’s dosing limitations from 10 mg to 20 mg when the drug is administered alongside the antiarrhythmic drug amiodarone.
In June, the FDA considered limiting the use of the highest approved dose of simvastatin after it was found to have a potential link to muscle damage in patients. The FDA recommended that the 80 mg dose be used only in patients who have been on the dose for 12 months or more with no sign of myopathy.
The FDA also added contraindications to the drug’s label for using simvastatin with other medications. The agency lowered the maximum safe doses of simvastatin when taken with certain interacting drugs; however, the FDA said the simvastatin dose limitation when co-administered with amiodarone was made in error.
“Unlike other interacting drugs, there were no pharmacokinetic or clinical trial data to support the simvastatin dose reduction approved with amiodarone,” according to the FDA.
Therefore, the agency said that for patients administered both simvastatin and amiodarone, the dose of simvastatin was restored to 20 mg. Under the FDA’s Drug Safety Communication, the labels for Zocor and its generic, Vytorin, were updated to include the aforementioned indications.