I have taken Zetia for the last 2 1/2 years along with 80 mg. Pravachol. My cardiologist felt that the Zetia would enhance the Pravachol and it does. I am lucky, no side effects. Although I do have mid back pain, the doctors all think it is a bulging disc. I do not have the muscle pain in my legs. You MUST get a CK blood test to see if your muscles are affected. Normal range is 0-165. Mine was 201 but the cardiologist said it is nothing to worry about. My total cholesterol is 173, HDL is 64 and LDL is 80. The new American Heart Association standard for heart attack victims is to have an HDL lower than 70 (others should not worry if they are at 100 or lower). My doctor is aiming to get mine down to the 70 mark but we are having a difficult time. No more snacks, holidays are over, and he has given me 4 months to accomplish new numbers. He is very, very strict with me and I appreciate that since he is a wonderful and caring cardiologist. In some cases, heredity is the enemy, and in my case it may very well be that. I will do my best and if I don't succeed, he plans to change meds again.