My husband has been in pain mgmt for several years. At his visit on Friday, he was given a UA drug screen and tested positive for cocaine. He had a kidney removed 2 yrs ago due to cancer. He hasn't had any further treatment for that. He is a diabetic and is on glyburide. He also is on Prilosec and takes naprosyn, tylenol, motrin, and Ny-Quil on an as needed basis. My question is what is the probability of him getting a false-positive on his drug screen?