This drug may produce a false positive immunoassay for this illicit substance? What is the drug and what is the illicit substance?
Dextromethorphan has been significantly associated with false positive results for PCP on urine drug screen tests in multiple case reports and a retrospective analysis from 2015. This is likely due to its structural similarity with PCP.
Rengarajan A, Mullins ME. How often do false-positive phencyclidine urine screens occur with use of common medications?.Clin Toxicol (Phila). 2013;51(6):493-496. doi:10.3109/15563650.2013.801982
Submitted by: Mary O’Keefe, PharmD and Ryan Feldman, PharmD, DABAT on behalf of the Acute and Intensive Care Section