Feedback on False Positives from Drug Testing, page 19

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 we do not give medical or legal advice.

Subj: Tested positive for cocaine
Date: 8/15/2007
Help! I tested positive for cocaine but did not have any but had a sinus infection and was taking Cipro, Diflucan, Sudafed, flucanase nose spray, prozac, desiprimine, Tegretol, thyroid (synthroid, BP med fosonopril, and received injection at the doctors office. Was also using kanka sore mouth reliever and valtrex. Could any of these cause a false positive? When the test is confirmed, will they rule other drugs out? Thanks


AskDocWeb: I hope you were not taking all of that just for a sinus congestion. Sudafed has been reported to cause a false positive for amphetamines and ecstasy, and Cipro for opiates.

Subj: Methadone
Date: 8/16/2007
Does methadone test positive for opiates in a urine test?


AskDocWeb: We’re building a list of products that cause false positives, not true positives as would methadone.

Subj: Tested positive for cocaine
Date: 8/16/2007
I recently tested positive for cocaine on a pre employment urine analysis with an airline company! I take Prozac, estrogen, hydroxycut, xanax and trazadone for migraines. I have also taken phentermine. They have suggested I request the split sample be tested at a different lab (at my expense). Can any of these drugs or a combination cause a false positive and if so, would a different lab be able to determine what has caused the false positive? Thank you for your help.


AskDocWeb: Getting tested at a different lab is one thing, but having that other lab find the cause of a false positive is a much bigger (and more expensive) job. Getting a GC/MS confirmation test would cost less.

Note: In 2003 the state of Missouri sued the maker of Hydroxycut for not disclosing safety risks and claims that Hydroxycut was “clinically proven” to be a “fat-burner” were false.

Subj: Methadone
Date: 8/16/2007
Client tested positive for methadone. Swears he has not used it. Is there anything out there that could cause a false positive? thanks sandy


AskDocWeb: Nyquil Nighttime Cold Medicine has been reported to cause a false positive for Methadone for up to 2 days after taking it.

Subj: Can they tell?
Date: 8/17/2007
When a lab test is done…can they tell the difference between detection of prescribed Marinol and chronic smoked marijuana? Thanks.


AskDocWeb: Yes they can and they can tell the amount of each one. So if you’re abusing a prescription drug they will find that out too.

Subj: Positive for Barbiturates
Date: 8/19/2007
Hello I need help! I just started a very good job that I really enjoy. They gave me a urine test. Friday they informed me that my test was positive for Barbiturates. I have never taken a Barbiturate and I honestly DO NOT know what could have caused the positive result. So can you please give me a list of things that can cause a positive result for Barbiturates. If I do not figure this out I cannot go back to work. Thank you,


AskDocWeb: Think back, did you take anything, even over the counter, that you usually don’t use. At the very least you should get a GC/MS confirmation test. That would reveal the urine test was a false positive.

Subj: Afrin nasal spray
Date: 8/19/2007
Hello, I’ve been using Afrin nasal spray once in a while. Now I know by taking that I fail a drug screening. But what do I do? or is that excusable from the test?


AskDocWeb: Just tell them that you are taking it.

Subj: Failed drug test for meth
Date: 8/20/2007
I have a few questions that maby you can answer. I have a friend that just failed a drug test for meth. She said she had never tried the drug though. How could the meth have gotten in her system? The pills that were in her system at the time of the test were: hydrocodone, pepcid 40mg, promethazine, hydroxyzine, and volume. Any help you could provide would be greatly appreciated. Thanks.


AskDocWeb: She may or may not have actually had meth in her system. Promethazine has been reported to cause a false positive on some drug tests.

Subj: Amoxicillin
Date: 8/20/2007
I have a question I am taking amoxicillin and I can pregnant and I had taken a drug test will that come up as a positive urine for cocaine?? please help


AskDocWeb: It’s possible that it will but the chance is small.

Subj: Leftover prescription
Date: 8/21/2007
My fiance is on a strict probation and was sentenced to do time in a diversion center. He was not tested prior to going in to the center for dirty urine. 25 days later they popped a urine test on him and he tested positive for amphetamines and marijuana. He was sick and I had gave him tri-vent hc which was left over prescription for my daughter it contains pseudoephedrine, carbonoxomine and hydrocodone, he took probly 3 tablespoons and it was about 4-5 hours before the drug test took place. Would it cause a false positive on a urine drug test? Please help! He’s in jail? Thanks,


AskDocWeb: If they found a prescription drug in his system and he doesn’t have a prescription for that drug, that may not be a false positive. It is our understanding that it is a crime if you take a prescription drug that doesn’t have your name on the prescription. They are a controlled substance for a reason. You can’t legally share a prescription drug.

Subj: Failed a u/a
Date: 8/22/2007
I failed a u/a today at a power plant for stuff I was not informed of. I was told my urine was being sent to the lab for final results. Will the lab know the difference from false positives and true readings? My employment hinges on they’re results. I take daily B complex, C 1000, mega green tea supplements. Have no idea what I failed. Didn’t study for this particular test. Thanx,

Richy Ga

AskDocWeb: Without knowing what test they are using it’s difficult to say how accurate the results will be. Whenever you fail a drug test, ask for a confirmation test, especially if it may cost you your job.

Also note that there are some health concerns about using Green Tea.

Subj: Amoxicillin
Date: 8/22/2007
I tested positive for cocaine when taking amoxicillin for a UTI. I know that I didn’t touch any kind of drug. Is it possible to give a false positive?


AskDocWeb: Yes.

Subj: Urine drug test
Date: 8/23/2007
The last day I took my 37.5mg of Phentermine was on Monday (I TAKE 2 A DAY)and on Thursday I had to take a urine drug test for work. Will this show up on the test? I do not take the Phentermine every day.


AskDocWeb: Yes it will show up in a urine test. Make sure you tell them you are on this prescription drug.

Subj: Oxycodone
Date: 8/24/2007
I am on Oxycodone and took a urine test that tested positive for Hydrocodone. I do not take hydrocodone, what could cause a false positive.


AskDocWeb: It is not a false positive when the drug you are taking is derived from opium which is the case for Oxycodone. It is a drug subject to abuse just like other opioid agonists, both legal and otherwise. Hopefully you can show them that you have a legal prescription for the drug.

Subj: Amitriptyline and Anti-Depressants
Date: 8/27/2007
My husband takes Amitriptyline – Anti- Depressants for about 8 years (50 to 100 mg a day. He just tested positive for marijuana? Can this drug give you false readings?


AskDocWeb: An anti-depressant called Zoloft has been reported to sometimes test positive for benzodiazepines and Amitriptyline has shown up as LSD.

Subj: Tested positive for Marijuana
Date: 8/27/2007
My son tested positive for Marijuana. Are there any drugs could cause this false positive? He has RX’s for: xanax, percocet, lortab, cymbalta, digoxin, and takes zanaflex and also takes a lot of sudafed and ibuprofen. Can prevacid or prilosec or zantac cause false positives? Thanks,


AskDocWeb: That’s a lot to take at the same time. It sounds like he was he in a severe car accident. Here is our current list of products reported to sometimes cause a false positive for Marijuana (THC):

  • Advil
  • Aleve
  • Anaprox
  • Ansaid
  • Bayer Select Pain Relief Formula
  • Clinoril
  • Cramp End Tablets
  • Dolobid
  • Dronabinol
  • Edecrin
  • Excedrin IB Caplets
  • Feldene
  • Flurbiprofen
  • Genpril
  • Haltran
  • Ibuprin
  • Ibuprofen
  • Ifenoprofen
  • Indocin
  • Ketoprofen
  • Lodine
  • Meclomen
  • Medipren
  • Mediprim
  • Midol 200
  • Motrin
  • Nalfon
  • Naprosyn
  • Naproxen
  • Nuprin
  • Orudis KT
  • Orudis
  • OTC allergy preparations
  • Oxaprozin
  • Pamprin
  • Phenergan
  • Promethegan
  • Riboflavin (vitamin B2)
  • Rufin
  • Some sleep aids
  • Tolectin
  • Trendar Cramp Relief Formula
  • Voltaren

Read more feedback about false positives:

Read Previous
This is page 19 – NextLast Page 300

If you find this page useful share it with others. All new questions will be answered by Doctors online.