Can Cough Syrup Cause A False Positive?
Can Cough Syrup Cause A False Positive? The initial screening for drugs of abuse invariably poses the risk for false positives due to cross-reactivity. The over-the-counter antitussive medication dextromethorphan (DXM) can cause false-positive results for phencyclidine (PCP) upon urine drug screening (UDS). Will cough medicine affect a drug test? Dextromethorphan, the active ingredient in Robitussin,