Shortly before Christmas 2007 my doctor decided my LDL was too high (104) so changed me to Vytorin from just Simvastatin. Shortly after the new year I became so weak that I would look at my stairway and wonder how I was going to manage going up for the night. I was extremely tired and terribly weak, hurting all over. I didn't even want a back rub from my husband because I hurt so bad. I arbitrarily stopped taking the Vytorin and resumed my Simvastatin (40mg/day) When I called my doctor he poo-pooed my symptoms and said if I had those symptoms with Vytorin I would have them with the Simvastatin. 2 weeks later my cardiologist assured me that I was not imagining the symptoms and increased my Simvastatin dose to 60mg/day which seems to be fine. Three of my co-workers experienced the same problems and took themselves off medication. Doctors...listen up!!!