Oh goodness! Jim is on Zocor too and has been having horrible leg pain and spasms. We never thought about Zocor, whoa! He even started a new med to help with the pain. My goodness, I wonder? I think it's mainly a concern because this can be a sign of kidney damage. I didn't see the rare symptoms though. So far Jim's kidney functions are fine but if a rare side effect is muscle pain it does make you wonder. I just know if I was to say to his doctor it could be the Zocor he'd say it's Jim's ms. He may be right, who knows since his kidneys are fine.