drug screenings

What Can Cause False Positive For Methadone? Several medications can produce a false-positive result for methadone on the urine drug screen: diphenhydramine, doxylamine, clomipramine, chlorpromazine, quetiapine, thioridazine, and verapamil. What creates a false positive for methadone? Antihistamines, analgesics, cough suppressants, and heartburn medications have been shown to cause false-positives in studies and case reports. False-positive