Taking Nyquil And Sudaphed For Cold And Meklazine. Test Showed Positive For Methamphetamine. Cause?
Though urine drug screens are usually accurate and specific to the substance that is being screened for, sometimes, there can be false positives.
Among the medication which you have mentioned, Sudafed contains "pseudoephedrine" and it has been reported that this can sometimes give a false positive test for amphetamines.
Urine drug screens actually detect the metabolitites or break down products of the drug in the urine. Rarely, the metabolites of some other substances can have similar molecular structures and hence reslt in false positives.
So, if you are sure that you have not taken any drugs, you can inform the lab that you have been taking Sudafed recently and maybe, request for a re-test or a blood / hair test.
Wish you all the best.
Regards,
Dr. Jonas Sundarakumar
Consultant Psychiatrist