What can cause a false positive for methadone?

Used for the treatment of ADHD, this Ritalin is a well-known cause of false positive tests for both amphetamine or methamphetamine and LSD. Doxylamine, found in Unisom and other over the counter sleep aids (similar to diphenhydramine), may cause a false positive on a drug test for methadone, opiates, and PCP. read more

Factors That Affect False Positive for Methadone As long as those drugs or their metabolites are still in your system, they are likely to cause a false positive for methadone. Importantly, there are other factors that can significantly affect the false positive results of Methadone’s tests. read more

Hi, Thank you for your input, There are several drugs that can cause false positive urine test for methadone, These are phenothazines, verapamil and related drugs, barbiturates, narcotic analgesics. In your case your medicine loratab, wellbutrin, cardizem and xanax are the possible medicine that can cause your methadone urine test positive. read more