A 46-year-old man takes simvastatin 40 mg at night and amlodipine 10 mg daily. What should he do?

• A. Stop Simvastatin
• B. Change to another statin
• C. Increase the dose of Simvastatin
• D. Reduce the dose of Simvastatin

Answer: (D)

There is a notable interaction between simvastatin and amlodipine that increases the risk of muscle toxicity (myopathy, and in severe cases rhabdomyolysis) because amlodipine can raise simvastatin levels in the blood. With this combination, the safest approach is to lower the statin dose to reduce this risk while still providing lipid-lowering benefits. Reducing from 40 mg to a lower dose (often 20 mg or less daily) helps achieve the goal with fewer adverse effects. Stopping the statin would remove cardiovascular protection, and increasing the dose would raise the toxicity risk. Switching to another statin could be considered if goals aren’t met or if further safety adjustments are needed, but the immediate, best step in this scenario is to reduce the simvastatin dose.