How long have u been on simvastatin? The dose can be increased to 80mg if necessary. cpk is an emzyme found in both skeletal muscle and cardiac muscle. If it was normal then u do not have rhabdomylosis, which is the side effect of simvastatin which your doctor was looking for. He has done the correct test and the result was negative. Return to doctor for further investigation of these muscle aches. They can be a side effect of simvastatin, but it is not the serious side effect of rhabdomylosis
the most common side effects of simvastatin are headache, abdominal pain/cramps, constipation, URTI, flatulence, diarrhea, asthenia, nausea and vomiting, dyspepsia, myalgia, rash/pruritus(itching). make sure you do not take with grapefruit juice, report any signs and symptoms of infections, unexplained muscle pain, tenderness/weekness. i hope this helps!!! this all i know about the med.
I wonder if the doctor really knew what he was doing- were you complaining of chest pains that he was checking cardiac enzymes? Muscle aches I believe is quite a common side effect of statin drugs. It can potentially be an early indicator of a very serious condition called rhabdomyolysis that can be a side effect. Dark urine can also accompany rhabdomyolysis. From what I see on line, creatinine kinase is what your doctor should have tested and if it is elevated, the drug should be discontinued.