Do over the counter cold medications interfere with a drug test and cause an error in the test?
The over-the-counter cold medications are structurally very similar to amphetamines and may cause interference in the initial screening test, but not in the confirmation test by GC /MS which is the only approved confirmatory technique in certified laboratories. It is important that all screening tests be confirmed and not all labs do confirmations. The compounds that were talking about are pseudoephedrine (Sudafed, Actifed, Contac Drixoral and many others), phenylpropanolamine( Robitussin, Triaminic and others) phenylepherine (Dristan, Neo Synephrine and others) propylhexedrine (Dristan, Benzedrex) and ephedrine (Primatene, Bronkaid). These compounds are present in many prescription and over the counter medications, It is important to do GC/MS to eliminate the chance of a false positives due to these structurally similar compounds.
