Myositis Pain and Marijuana Use Question I have Polymyositis. My cpk levels are always 2500-3000. I smoke marijuana and I was wondering if it could make my levels so high? Answer March 26, 2008 By Jon Giles, MD The muscles of polymyositis patients tend to be very sensitive to the toxic effects of illicit substances. Thus, it is probably that marijuana use could contribute to your persistently elevated muscle enzyme levels.