Hello, CPK is an enzyme found mainly in muscles. Damage to the muscles causes this enzyme level to rise. Fenofibrate is a possible cause of your problem particularly if you were also using a statin. Other possible causes of muscle damage include muscle injuries, intramuscular injections, strenuous exercise, very low potassium levels, other drugs, inflammatory myopathies, heat stroke etc. Since this condition could hurt your kidneys, I suggest you drink enough fluids - if you doctor has not forbidden you to do so for other medical issues - and check both the cpk and kidney function with creatinine and urea measurements.