Hello J S Reames, I'm sorry to hear that your are having pain when you walk, especially considering excersize is a great way to lower your cholesterol. Your pain does not sound like a side effect of Zetia. You will want to discuss with your doctor whether or not you have a condition called lumbar spinal stenosis, a condition commonly called sciatica. The nerves that go to the muscles and skin of the lower extremities exit the spinal column through small holes. With age, these holes become smaller, usually on account of osteoarthritis, and compress the nerves. When that happens, you can get shooting pains in the buttocks, down the back of the thigh, which usually become much worse when walking. If you can take ibuprofen or naprosen, these over the counter medications usually make the pain much better. You should make an appointment with your primary care doctor to discuss these symptoms. Note when the pain is the worst, what activities make aggrivate the pain, and what, if anything, makes the pain better. Your symptoms are very useful in making the diagnosis! To your health, Neil MD