False Positives ForumThis forum is intended to help those who Do NOT Abuse Drugs. We do NOT support the illegal use of any substance. If you have experience with false positives, share your experience. What would you tell someone about drug testing and false positives? Please remember that we do not give medical or legal advice.
Subj: Positive for Meth
I tested positive on a urine test for Meth and haven't taken this drug. I have had a sinus infection and have been taking numerous over the counter things such as Sudefed, advil, benadryl allergy & sinus, Alka Seltzer Plus, Alavert. I rotated these things due the the fact I could not go to the doctor. I also am taking Phentramine (Hoodia Guarana)to suppress my appetite. Can you tell me if these drugs could be the cause? They tell me that none on them did, but there has to be a explaination and a way to clear myself.
AskDocWeb: Of the things you have taken, both Sudafed and Benadryl are on our false positive list.
Subj: Difference between barbiturates & benzodiazine?
What is the difference between barbiturates & benzodiazine? Are there over the counter medications that can cause false positives for these?
AskDocWeb: Barbituates are a whole class of drugs but benzodiazine is the name of a specific drug.
Subj: Tested positive for amphetamines
I have been taking Adderal 20mg 3x's/day for years. I also take Zyrtec-D, Nasonex, Singulair, Lortab, Phenegan and Donnatl. The last 3 listed I take PRN. I had a hair folical drug screen for a custody case and of course it came back positive for amphetamines. The result was confirmed by GC/MS at Amphetamine 8518pg/mg & methamphetamine 246pg/mg. Please explain this to me, I have not used meth or anything else except my prescription meds. THANK YOU!
AskDocWeb: Upon checking your list we found that Lortab is an opioid analgesic. Thanks Susan, you've added another one to the list.
I recently tested positive for cocaine. I told the testers and the Doc who gave me the results that I have chronic bladder/kidney infections and was currently taking macrobid for the issues. My employer was told that there wasn't anything that would cause this false positive with this testing. Is this true?
AskDocWeb: Macrobid is not on the list for causing a false positive.
Subj: Tested positive for cocaine
One of my subordinates received a positive for cocaine. The report said he had 18,060 nanograms in his system. He had been taking Naproxen, and Percocet which was prescribed. The amount found seems extremely high (no pun intended). I want to believe he did not use cocaine, and the 18,060 ng's is almost unbelievable. What do you think?
AskDocWeb: Percocet and Naproxen are both on the list of drugs that can cause a false positive but we are unable to give you any specific numbers. He must be in extreme pain to be taking anything like percocet. It is a semisynthetic opioid analgesic, as in derived from opium.
My boyfriend tested positive for PCP on a urine test after taking Nyquil liquid gelcaps for a cough.
Subj: Advil Cold and sinus
My sister just tested positive for meth but hasn't used it in 6 years. She does take Advil Cold and sinus. Can this cause a false positive?
AskDocWeb: Yes, it can if the testing is done with one of the cheap drug tests. A GC/MS test is more accurate but it's also more expensive. Too many businesses opt for the cheaper tests.
Subj: Failed test for opiates
I took Nyquil for a cold and failed a test for opiates. I hadn't taken any pain killers or anything else besides ibuprofen for that matter should it be either?
AskDocWeb: Both Nyquil and Ibuprofen are on the list of drugs that may cause a false positive on drug tests. See the list here.
Subj: Cocaine metabolite
I was taking doxycycline, zithromax, biaxin, and cipro at different times over a two week period. I also was prescribed percocet, demerol, afrin, deconomine, valum and motrin all for a sinus fracture/sinus infection.(emergency aircraft depressurization) Of course these all showed up in my urinalysis for work. Cocaine metabolite also showed up. How can this be possible?
AskDocWeb: It looks like you are on several drugs that can cause a false positive; Percocet, Demerol, Afrin, Valium, and Motrin. The accuracy of urine tests are getting better but they are not yet 100% accurate. Other substances are still confused with the metabolites of cocaine. That is why a confirmation test is required in most cases.
Subj: Drug test
My cousin had a drug test recently for marijuana, he knew had done drugs (mara) about 3 weeks to a month prior, so he thought he would be clean the night before he took 2 of his grma's Motrin 800mg for a servere headache, the next day he failed the test and it showed up very good. Could this have been due to the drugs a month ago or the Motrin.
AskDocWeb: It could be either one because Motrin is on the list as causing a false positive.
Subj: Bad drug test
I had a drug test for work and did not pass. I take valtex every day, would that cause a bad drug test? I don't do any thing else.
AskDocWeb: Valtrex is not on the list of drugs that can cause a false positive.
Can Contac cause false/positive for cocaine?
AskDocWeb: Yes, it can cause a false positive.
Subj: Tested positive on home drug test
I tested positive for cocaine on a home drug test after trying for the first time 7 days ago. I read it took 5 days max to leave your urine. I heard kidney disease can cause false positives.
AskDocWeb: Some of the drugs used to treat kidney disease may cause a false positive but the disease itself does not.
Subj: Valium in urine?
I take xanax but when I took a urine test they said the found a valium sub in my urine. I don't take valium, what could cause this?
AskDocWeb: The chemical formulas of Valium and Xanax are similar. Both in the benzodiazepine class of central nervous system-active compounds.
Subj: False positive for opiates
I know that Vicks 44 can make a false positive on a drug test for opiates but what else can give you a false positive for opiates?
AskDocWeb: Any drug obtained from opium or that has such a drug as one of it's ingredients, such as codeine or a mixture that contains codeine can cause false positives.
Subj: Passing cocaine?
Is it possible for someone to get drugs in their system through sexual contact with a user? My cousin, who has never tried drugs tested positive for cocaine 3x. It turns out his girlfriend is a regular user. Is it possible that the cocaine got into his system through sexual contact with her? Thank you.
AskDocWeb: Yes, if his girlfriend uses cocaine, she may have had cocaine on her skin. And if he kissed those places he may have taken it into his body.
Subj: Pre-employment drug test
I just took a pre-employment drug test. At the time I was taking Valtrex for cold sores and I'm also on aspirin therapy. Will this give a false positive on my drug test.
AskDocWeb: No, neither Valtrex nor aspirin will cause a false positive.
Subj: Failed a urine screen
I am currently a patient at a methadone clinic. I also have hepatitis C. I recently have been told that I failed a urine screen, the first in over a year and a half for cocaine and opiates I heard that liver disease can cause a false positive for both. I really didn't use, I was told I'm a drug addict and no one will believe me anyway so I'm better off just admitting it. So I made up a story. I also had a cold and took some Nyquil the day before the urine and was on amoxocillin for a staff infection. Is there any way that this could have brought up a false positive? I need to know. Thank you.
AskDocWeb: Yes, both Nyquil and Amoxicillin have been reported to cause a false positive.
Subj: False drug test
False drug test came up for THC, and I've never smoked in my life. I take 200mg of zoloft the highest dosage. Could this be it?
AskDocWeb: There have been no reports of Zoloft causing a false positive. Did you take any cold medicines?
Subj: Tested positive for meth
My brother tested positive for meth that with a mouth swab that same day he had gone to the dentist and had teeth removed and teeth put in. He had also taken a prescribed decongestant and has been taking the diet pill phetermine, can any of this cause positives?
AskDocWeb: Yes they can. If drug tests are going to occur every 6 months or every year, he will need to be very careful about what he takes or he will end up in trouble.
Subj: Test for THC
I wanted to know if Enzyte can cause false positive tests for THC. My husband has only taken that any Advil. We can't think of anything else that would cause this. He has never done any drugs in his life. Thank you for your help.
AskDocWeb: Advil is on our list of drugs that may cause a false positive. We haven't heard of Enzyte causing one but that's not to say that it couldn't.
Subj: Take many drugs
I was prescribed phenobarbital 4-5 weeks ago and took it for one (1) week. Last week and yesterday, the level of phenobarbital in my system was very high (according to Doc); he informed me life of this drug is only 3-4 days and doesn't believe me that I only took it for 1 week. I am looking for reasons for a false positive. I take many meds: trileptal, trazadone, zyprexa, naladol, paxil, just finished 10 days of prednisone (taper), nexium, levaquin, lovastatin, seroquel, allegra, topamax and albuterol. The only thing I can find a possible contra is from the trileptal or, perhaps, the steroids. Again, no phenobarb for at least 3 weeks. This is very disturbing, since he thinks I'm a liar. Can you shed any light? Thank you so much,
AskDocWeb: The more drugs you take the farther into unknown territory you get and the greater the chances of unwanted reactions. Have you considered changing doctors to get another opinion?
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