Several medications can produce a false-positive result for methadone on the urine drug screen: diphenhydramine, doxylamine, clomipramine, chlorpromazine, quetiapine, thioridazine, and verapamil.
Add a new one to the list. Tapentadol, a relatively new opioid analgesic similar to tramadol, can also produce a false-positive result for methadone on certain immunoassays.
A separate study concluded that tapentadol does not affect the amphetamine screen.
References
Brahm NC, Yeager LL, Fox MD, et al. Commonly prescribed medications and potential false-positive urine drug screens. Am J Health Syst Pharm 2010;67(16):1344-50. [PMID 20689123]
Tang S, Mullins ME, Braun BM, et al. Can tapentadol cause a false-positive urine drug screen for amphetamine? Clin Toxicol 2012;50(10):1174-5. [PMID 23088194]
