what causes false positives?

Question

I don't smoke weed. but i got arrested twice for "dirty" tests. what can possible cause false possitives?

Answer 1

Second hand smoke can sometimes cause a test to be positive, but there are also a few medications that have been reported to cause false positives on some urine assays for marijuana (THC or cannabinoids). Ibuprofen (Advil or Motrin) and some other NSAIDs (ketoprofen, naproxen [Aleve]) have been reported to cause false positives. Sustiva, an HIV drug, has also been in the news for causing false positive urine tests. Some heartburn meds called PPIs (Protonix, Prevacid, Prilosec, Aciphex) have also been in the news for causing false positive urine tests. There is also a prescription medication derived from marijuana called Marinol (an appetite stimulant). This can cause a positive test as well. Usually if there is the possibility of a false positive, a more accurate, confirmatory test can be done. Do you think any of those might be the culprit?

Answer 2

Yes, prilosec or Omeprazole caused me to test positive for THC on two occassions. On one day, I tested myself at home and the results were negative. I took prilosec and tested positive later that same day. On both occasions my test was negative the next day after not taking prilosec. A lab can rule out the false positives. Unfortunately in my case the judge ordered the testing and I was jailed twice with them refusing to do the further lab confirmation.