I have been on a combination of zetia and niaspan for about 3-4 years. I have been experiencing continual muscle pain in my legs mostly upper thighs for about 6 or 7 months on and off but the last two months almost constantly. Can this happen with this combination. Years ago I had trouble with statins and my doctor then took me off of them and said my ratios were good so she didn't think I needed to be on them.