 [ Symptoms ] what medications can result in a false positive for illegal methamphetamine in a urine analysis who is never used before i am having bariatric surgery my labs came back pos for methamphetamine when i have never done any drugs in my 40yrs of living are there otcprescribed meds that could cause this because of the results they want me to do treatment & wait a yr before surgery which is for my severe acid refluxobesity i am mortified since i have never used illegal drugs i am on several prescriptions it has taken me 20 yrs to finally get my insur to cover this surgery just to have this happen  please help [ Disease ] if i had the list of prescriptions you are taking now perhaps i could be of more help amphetamines are in a class of drug called sympathomimetic amines and some decongestants like pseudoephedrine and even some combination cold medicines can cause a false positive result some over the counter weight loss medications often contain them just give the list to your doctor and have himher figure it out if you have not been taking any amphetamines then just have the test repeated