A patient on statin therapy presents with muscle pain; which is the most common adverse effect of simvastatin at 40 mg daily?

• A. Headache
• B. Myalgia
• C. Nausea
• D. Rash

Answer: (B)

Muscle-related symptoms are the most common adverse effects seen with statins. At a dose of 40 mg daily, the most frequent issue reported is myalgia—pain or aching in the muscles, which often occurs without significant findings on examination or marked CK elevation. This contrasts with myopathy or rhabdomyolysis, where CK levels are elevated and there is a higher risk of serious complications; those are less common than myalgia.

Other listed adverse effects like headache, nausea, or rash can occur with statins but occur less commonly and are not as characteristic of simvastatin therapy at this dose. If myalgia develops, assess CK levels and consider dose adjustment or evaluation for contributing factors and potential drug interactions.