Questions about False Positives in Drug Testing, page 281

False Positives Forum

This 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 this forum is not for medical or legal advice.

Date: 3/28/2013
I am prescribed 550mg of naproxen(sp?) for cramps & back/neck/shoulder pain. I tested positive for thc & went to a lab to get more testing done. Do all labs have the capability of performing a gc-ms test? If so, is it still possible the naproxen will still show up as thc?


AskDocWeb: Not all labs can perform the GC/MS test. Even among those that do the test there is a wide range in error rates due to the quality of their work. We recommend that you use a lab that is certified by SAMHSA. That’s the federal Substance Abuse and Mental Health Services Administration. Uncertified labs don’t maintain the high quality standards required for certification and have higher error rates. For a list of SAMHSA certified laboratories see page 185.

According to a Toxicology Lab Technical Brief from Dr. Joseph Graas, Ph.D. published by Medical Assisted Treatment of America (a non-profit organization), Naproxen may show up as a false positive for THC (Reference: 18).

Date: 3/28/2013
I failed a drug test today for oxycontin, meth, and xannex but I havent done any of these nor have I done any other drugs. I been drinking tons of redbulls. Can they cause all these possitives or is someone tampering with my drug screenings???? HELP!!!!


AskDocWeb: We don’t know about the possibility of tampering but Redbull has not been reported to cause any false positives on urine drug tests for drugs of abuse.

Methyldopa positive for amphetamines?
Date: 3/28/2013
I am 8 weeks pregnant and currently taking methyldopa 250mg twice a day for hypertension. My only other medications are prenatal vitamins, iron, folic acid and calcium. I recently had my 1st ob/gyn appointment and received a phone call afterward that my urine was positive for amphetamines. I am an RN and do not use drugs. I also have 2 other children. I am very concerned as to how this could happen and worry about this affecting my job. The lab test was performed at the hospital where I work. Any evidence that this can be caused by the methyldopa? I also took it with my last pregnancy with no problems.


AskDocWeb: Although so far we have been unable to document this, others have reported having problems with methyldopa showing up as amphetamines. See the post by Marcie on page 264.

Epi-pen and Doxycycline combination?
Date: 3/29/2013
Epi-pen and Doxycycline combination; Can these two (Doxy is 200mg a day, epi one time)combine to show up as a false positive for Meth? I am a peace officer, fender bender off-duty in my driveway and urine test showed positive for meth. I’m 50 yrs old and again I’m a cop, haven’t done meth in 30yrs, how can this happen?


AskDocWeb: This sounds too much like the post from Renee which was answered yesterday. Please see the post titled Officer in trouble.

Lost my job because of this
Date: 3/29/2013
I just had a random drug screen done at my previous employer on 3/21/13. The test results came up positive for opiates. I have not taken any form of opiate whatsoever for over a year, 0r any type of drug for that matter. The last time I remember taking an opiate(which was hydrocodone) was in April of 2012 when I had dental work done and I was in a lot of pain. For about 4 days prior to the drug screen, I was taking Mucinex DM Extra Strength(1200mg per 12hrs), sudaffed and I also coincidentally ate a poppy seed bagel 2 hours before I was given the random drug screen. I am also prescribed Nexium 40mg for acid reflux that I take once a day. Would either of those cause a false positive for opiates on a 5 panel and 10 panel test?

I defended myself in that I do not take any type of drug and even had a hair follicle test done that I paid for and the results were negative. Something I ingested had to of caused the false positive and I’m trying to figure out what it was. I lost my good job of 4 1/2 years due to this and I’m desperate for answers so I can clear my name.

AskDocWeb: There are several sources that say poppy seeds contain morphine and can show up as opiates (References: 3, 16, 17, 20, 21, 25, 26, 29, 32, 48, and 60), that includes the American Medical Association as well as the manufacturers that make the drug testing kits. Those who are subject to drug testing would be wise to avoid eating poppy seeds.

In order to clear your name you would have to prove that the original test was in error. That mean the original sample would have to undergo additional testing by a more accurate method. The GC/MS test is currently the “gold standard” for confirmation testing.

Antidepressants, inhalers, and OTC allergy medication?
Date: 3/29/2013
I’m a union rep. and presently trying to defend a union member that had a false/positive reading on a random drug test. My question is can antidepressants, inhalers, over the counter allergy medication cause a false/positive breathalyzer reading? Your input would be greatly appreciated and could you please give me more on what other prescriptions by name that may cause false/positive breathalyzer readings. Thanks,

AskDocWeb: A complete answer would take several of days of research but we can get you started. The following products used to treat allergies have been documented to sometimes show up as a false positives:

  • Allerest
  • Alavert
  • Claritin
  • Claritin Hives Relief
  • Claritin Reditab
  • Clear-Atadine
  • Clear-Atadine Children’s
  • Ohm Allergy Relief
  • Afrin (Oxymetazoline Nasal Spray)
  • 4-Way Nasal Spray
  • Sinarest
  • Sine-Off
  • Sinubid

The list of all substances that we have been able to document for producing false positive can be found here.

False positive for oxycodone
Date: 3/30/2013
hydrocodone and cymbalta came back as oxycodone that i havent taken


Positive for amphetamines?
Date: 3/30/2013
I starting taking Zantac and Raspberry Ketone for the last couple of months. Recently I had a drug test that came up positive for amphetamines. I have bad anxiety and panic attacks so I would and could never take amphetamines. Why would my urine drug test come back positive for amphetamines?


AskDocWeb: Most likely it was the Zantac. According to IT Laboratories, which is an ISO-certified drug testing and toxicology laboratory, ZantacĀ® (Rantidine) may test false positive for amphetamines (References: 57). It is important to get a confirmation test on any positive result from a urine test. If you don’t then the results are not viewed as false and that may become a permanent part of your medical history.

Tested positive for benzodiazepine
Date: 3/31/2013
Can carisoprodol (soma) test positive in a U A for benzodiazepine? Soma was taken a day or so before a UA for a sleep aid. The test was positive for benzodiazepine. The only other drug taken was naprosin (alieve).


AskDocWeb: Although both your meds have been reported to sometimes show up as a false positive, neither has shown up as benzodiazepine.

Date: 4/1/2013
Can my depokote and hydroxycut make me test dirty?


AskDocWeb: So far there are no reports of either causing any problems on urine drug test for drugs of abuse.

5 htp or lemon balm
Date: 4/1/2013
my company has introduced urine drug testing. i take 5 htp (about 300mg per day) and lemon balm. is there any chance these will show up, even as false positives? many thanks,


AskDocWeb: 5-HTP (5-Hydroxytryptophan) is a naturally occurring amino acid produced by the body. It has not been reported to show up on urine drug tests. Lemon Balm does have a few health concerns but should not cause any problems with drug testing.

Read more feedback about false positives:

Previous Page
You are on Page 281 – NextLast Page 300