Right before submitting for a drug test, a donor is required to disclose any prescription or over-the-counter medication that has been taken in the past couple weeks. This procedure is required in order to avoid any confusion, because the purpose of the drug test is to determine illegal drug use and legally used medication should not interfere with eligibility to work and job performance. This is on one hand, but on the other – did you know that the lab has to provide a list of cross-reactants in instance when a drug test came back positive? A confirmatory test will be done, but they need to notify you that several prescription drugs may cause a false positive read of the test. Here are some examples:

A false-positive for Marijuana may be caused by such NSAID as Advil, Nuprin, ect.

A false-positive for Amphetamines may be caused by Diatec, Dexatrim, Cotylenol, Triaminic, Primatene, Bronkotabs, Nyquil, etc.

A false-positive for Opiates may be caused by Elavil, Demarol, Tofranil, Mydol, Permensin, Prematene-M, Vicks Formula 44-M, etc.

Prematine also can cause a false positive for Barbiturates as well, and Benadryl can come up as Methadone.

Disclosing the cross-reactants like these before the test gives a certain legal shield to both employer and an employee.

Some people prefer not to disclose certain prescription medication like anti-depressant or psychiatric tablets, because it reveals a medical condition and this information may be used to discriminate against disabled people. It is good to know possible cross-reactants and choose wisely what facts to disclose to an employer, and what things need to remain private.