Feedback on False Positives from Drug Tests

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: Failing drug tests
Date: 1/26/2005
My husband takes Phenergan and Zantac on a daily basis. He also goes to a Methadone clinic. He passed had every drug test for over a year. Nothing changed he always took these drugs. But he started failing the drug tests. They said it was for Amphitamines. Is this possible? He has passed other drug test given for work. At the same time.


AskDocWeb: Phenergan is for nausea and vomiting, and only to be used for a short time just for these symptoms. The Zantac is on the list.

Subj: Tested positive for marijuana
Date: 7/23/2005
A friend of mine does not use drugs. Yet, his drug test came back positive for marijuana. He had been taking about 3600mg/day of ibuprofen. We would like to find reputable information related to ibuprofen causing false positives for marijuana.


AskDocWeb: Are you sure he tested positive for marijuana or was it positive for drug abuse? He is taking more than the recommended amount of ibuprofen and overdosing on ibuprofen is known to cause false positives for marijuana on test results.

Subj: Tested positive for heroin
Date: 8/6/2005
I feel completely helpless and hopeless. I test positive for heroin and I DO NOT use illegal drugs, but I do take quinine for leg cramps. The testing device is an ion (vacuum-type) device and info would be appreciated. Thank you.


AskDocWeb: If the lab that tested you wasn’t certified, we suggest you get tested by one that is certified. And let them know that you are taking quinine.

Subj: Quinine false positive
Date: 12/9/2005
Some websites state that quinine can produce a false positive for cocaine use. Is this true or is it only true for opiates?


AskDocWeb: As far as we know, it is only true for opiates.

Please note that there are some health concerns with using quinine.

Subj: Arrested for DUI
Date: 1/5/2006
I was pulled over a year ago and arrested for DUI. After blowing 0.0% because I had not been drinking the police gave me a 5 minute urine drug screen. They claimed it showed THC and meth.?? I use neither. I did tell them prior to the test that I had been taking metabolife and an over the counter allergy med I think Sudafed. All charges were dropped and they sent my urine to the crime lab. Now over a year later they have pressed charges. They said I did not have THC in my urine but I did have methamphetamine antanphetamines. I have never used these illegal substances, could the over the counters produce a false test? Thanks


AskDocWeb: Yes, Sudafed is known to cause false positives on some urine drug tests.

Subj: Tested positive for amphetamines
Date: 2/2/2006
I recently tested positive for amphetamines, I do NOT use drugs and this was for a really good job. I took Nyquil the night prior to the test because I’ve had a cold for the past 2 weeks. I know it had to be the nyquil, is there any way to convince the employer. Prior to the screening I did disclose the fact that I used Nyquil.


AskDocWeb: The only way we know to convice an employer when a urine drug test produces a false positive is to get a GC/MS confirmation test on the original sample.

Subj: False positives?
Date: 2/7/2006
Will any of the following give a false positive cocaine reading. Zithromax, Prednisone, Albuterol liquid, or Levaquin


AskDocWeb: Since Prednisone is a steroid, it may show up on a drug screen.

Subj: Hydrocodone false positive
Date: 3/8/2006
I recently took a drug test and tested positive for hydrocodone (per saliva test). I have Never taken hydrocodone or any prescription pain medication. The day of the test, I took 2 Excedrin Migraines and 2 ibuprofen. Could these two medications produce a false hydrocodone result?


AskDocWeb: We know that both Excedrin and Ibuprofen may cause false positives but at this time we don’t know if it was for hydrocodone or something else.

Subj: Positive for methadone
Date: 3/16/2006
Our company does random drug testing and called me the other day for a urine test. My results for methadone came up positive but I have never touched a drug in my life. I have not taken any medication and I have no idea what could have caused this. Is there any thing you can tell me that may cause a false positive.


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

Subj: Drug tests
Date: 3/23/2006
I am looking into a career with the CIA and was wondering if you had any idea how extensive their drug tests are. I have been taking Vicodin for my migraines, cold medication(Nyquil at night and Tylenol during the day) is this going to be a problem? Any info would be appreciated.


AskDocWeb: We are sure that the CIA knows which products cause false positives. Many people take Tylenol and Nyquil for their colds and they will know that, but to be on vicodin for a migraine is something else. That could be a problem.

Subj: In trouble
Date: 3/23/2006
My boyfriend got arrested for possession of marijuana and he quit smoking because he knows its not even worth getting in trouble over, but his drug test came back positive for opiates and he doesn’t do any drugs. He takes Advil sometimes for headaches and he just had a cold and took some cold medicine but other then that he doesn’t do anything. Is there any way at all to prove his innocence? He’s being told now there is a warrant out for his arrest and he will probably be arrested tomorrow…but for nothing and I don’t understand this. He’s got a warrant out for his arrest for doing what he is supposed to do and still he is in trouble…


AskDocWeb: For others in this situation, if you take cold medicine it may be helpful to keep the receipt as proof of purchase.

Subj: False positive?
Date: 3/24/2006
Can Fioricet cause a false positive for amphetamines?


AskDocWeb: Fioricet by itself has not been reported to cause a false positive but according to a Toxicology Lab Technical Brief from Dr. Joseph Graas, Ph.D. the EMIT urine test “cannot distinguish between morphine (the metabolite of heroin excreted in urine), codeine, and opiates, including poppy seeds commonly used in baked goods.” Dr. Graas lists Fioricet with Codeine as one of the drugs that could affect the results of a drug test.

Subj: Quite a few drugs
Date: 3/26/2006
I am writing to hopefully get some information on false positive urine screens for cocaine. I am on probation and my screens have been diluted. I was diagnosed with sinusitis and gastroenteritis and was given antibiotics and some nausea medication. I also take quite a few other meds for blood pressure cholesterol acid reflux pain meds I am listing the meds I take: atenelol, cyclobenzaprine, lisinopril, omeprazole, prochlorperazine maleate, propoxyphene, quetiapine, salsalate, simvastatin. The antibiotics I was on were co-trimoxazole 800/160, now I am taking cipro hcl 500mg. Would any of these medical issues or meds cause a false positive?


AskDocWeb: Because you are taking so many meds, it would be a good idea to provide the drug tester a detailed list of all the medications involved. There is an extensive list of drugs that may show up as a false positive here.

Subj: Failed drug testing
Date: 3/26/2006
Please Help. My son was arrested in Jan 2006 for possession of Marijuana, since then the Judge put him on SOR with Random drug testing. His tests were coming up fine. He got a very bad cough and Cold, so I gave him NyquilPM cough syrup and Coricidin Cough and cols which I take when I get really sick, I took him for his next drug test and The SOR office called me a week later and said my son violated his sor because opiates were found in his system. Also he loves Poppy seed bagels in the morning. Could any of this make him have a positive urine test. He also went and applied for a job at Target around the same time and had to take a drug test and we haven’t heard anything from them either.


AskDocWeb: Yes all of the above could of affected his drug tests. Sounds like he may need to give up the poppy seed bagels for a while.

Subj: Tested positive
Date: 3/31/2006
I had a positive drug test (forensic) come up for phentermine. I haven’t taken any Rx diet meds, wondering what else could cause a positive drug test for phentermine?


AskDocWeb: This is something that might take help from your doctor to figure out. You will have to go through all the pills and herbs that you’ve taken or used before the drug test was done.

Subj: False positive after a trip to ER
Date: 4/3/2006
My wife has just had cyst on her ovary and diagnosed with endrometriosis. While given several different meds. She is going to an outpatient rehab. She went to ER weds. Stayed in bed all day Thursday. Went to program on Friday tested positive for cocaine. Now they are recommending inpatient. Can you please assist.


AskDocWeb: Sounds like you need the help of your doctor here. With your doctor’s help you can get a list of the drugs that were given to her in the ER and find out what could have caused a false positive on that test. Tell him your wife doesn’t do drugs, and that you need his help with this. We wish you and your wife the best of luck.

Subj: Products that cause false positives
Date: 4/4/2006
Risperdol, tenex, topomax, stratera

Can any of these cause a false positive drug test?


AskDocWeb: None of those are on our list but we are always open to adding more. If you have evidence that any of these has caused a false positive, please let us know and we will investigate.

Subj: Urinalysis during heart attack showed THC
Date: 4/14/2006
I am a 27 y/o male who recently had a heart attack. While I was having the heart attack I was called into my work for a mandatory urinalysis. I was very thankful for this, because I wouldn’t have left my home unless I was called in. The results of the test came back yesterday and I was found to be positive for THC. I have smoked marijuana, but I haven’t since 2004. I have had numerous drug tests during this time and they have all been negative, I was wondering if the fact that I was having a myocardial infarction during my urinalysis would have released THC that was stored in my fat since 2004? I really don’t have any other explanation for this occurrence. Any thoughts? I also took a 800mg Motrin when the chest pain started, I have read that Motrin may cause a false positive. I am in the Army, and the tests are pretty accurate I am told, so I don’t know what to do.


AskDocWeb: It is more likely that the Motrin caused the reading. About the only thing you can do is to let them know that you took the Motrin and hope for the best and request a confirmation test.

Subj: False positive?
Date: 4/17/2006
My husband and I have an ongoing case with CPS – they have our children. We have been completely clean for 6 months and were clean prior to their investigation. Now my husband has taken another hair follicle and it shows positive for meth and amphet. Even though he hasn’t used for 6 months plus. It is my understanding that the active ingredient in Zantac can cause this – (Rynatadamine?) Also, he has peripheral vascular disease. We’re wondering if the bad circulation could cause a false positive?

Puzzled – Ellis Co. TX

AskDocWeb: No, bad circulation wouldn’t cause a false positive but the Zantac could.

Subj: Failed UA – UA false positives?
Date: 4/21/2006
My brother, who is on probation, recently failed his UA. They said he had meth in his system. He swears he has not used in over 2 years, which we all believe. He is now in jail and we are trying to research false positives, to help clear him. He was/is taking two anti-inflamatories, acular and piroxicam. I have read that non-steroidal anit-inflamatories will cause a false positive for meth. This would be the piroxicam. How sure is that information? Will a drug such as piroxicam cause a false positive for meth?


AskDocWeb: We have recently discovered that too many organizations (in our opinion) are relying on the cheap EMIT test process alone. This is far from accurate and produces too many false positives. If there is any doubt about test results you should insist on getting a GC/MS confirmation test to prove your innocence. This test is much more expensive but is also virtually error free.

Subj: Failed drug test
Date: 4/30/2006
My boyfriend is taking weekly urine tests. He tested positive for cocaine. the meds he was on at time were penicillin VK, tylenol w/ codeine, Hydrocodone. Another used med was Azithromycin. Can any cause a false positive????


AskDocWeb: Yes, any meds with codeine in them could show up as a positive and the hydrocodone would also fail a urine test.

Subj: False positives
Date: 5/9/2006
Can you tell me all the false positives for cocaine please? Will tetracycline cause a false positive test for any drug? Will sudafed test positive for cocaine?


AskDocWeb: Tetracycline will not test positive for cocaine, although Sudafed could.

Subj: False positive?
Date: 5/20/2006
I am an athlete, and recently had my urine tested after a race, and they found prednisone/prednisolone/meticorten/meticortelone. I have never taken any of these substances, and am not on any medication. Occasionally I take Disprin. Is it possible to get a false positive on glucocorticosteroids?


AskDocWeb: What are the last 8 letters of glucocorticosteroids?

Subj: Postitive for hydrocodone
Date: 6/3/2006
I take morphine, trazadone, methocarbamol, estrogen, zyrtec, valtrex, and lisinipril and I keep coming up with a postitive for hydrocodone which I can’t take because it makes me sick, why?


AskDocWeb: The ingredients in a few of these drugs may have a small amount of hydrocodone in them.

Subj: Ephedrine
Date: 6/9/2006
I have been taking over the counter EPHEDRINE every day for about 12 years for asthma. Recently, I got UA’d and tested positive for METH! The cops don’t believe me, they raided my house for a meth lab and of course found nothing of that sort. I can’t find a lab to do the testing to get me out of trouble…HELP!!


AskDocWeb: It sounds like you may need to ask a lawyer.

Subj: Anbesol?
Date: 6/11/2006
Can Anbesol cause a false positive for cocaine – I have never used drugs in my life and tested positive for cocaine on a drug test for work – Anbesol has 20% benzocaine – and the molecular structure looks the same – also had tonic water when I was out for dinner the night before – please respond ASAP as I need an explanation.


AskDocWeb: We haven’t heard any cases of this happening with Anbesol.

Subj: Ephedra
Date: 6/12/2006
Will taking an Ephedra based fat burner cause a false positive if so for what and how long after useage?


AskDocWeb: Ephedra may cause a false positive for amphetamines and/or ecstasy but how long it stays in your system is unknown.

Subj: Percocet
Date: 6/13/2006
can percocet be mistaken for amphetamines or methamphetamines in a urine drug test?


AskDocWeb: Yes, it can.

Subj: Zantac false positive?
Date: 6/14/2006
One applicant was tested positive for metaamphetamine hydrochloride but claims that it was probably caused by Zantac that he is using for the treatment of his gastric ulcers. Is there a truth to that claim?


AskDocWeb: Yes, the Zantac has been reported to cause a false positive on urine drug screens.

Subj: Tested positive for THC
Date: 6/15/2006
I have taken Cipro and Zithromax, right before a piss test and I came up positive for THC, could this be the reason? I am not into drugs and they says it was marijuana. I am a soldier I don’t nor cannot use any controlled substance I have asked around, no one seems to know, can you help me?


AskDocWeb: They may have used EMIT test process which can produce many false positives. You might insist on getting a GC/MS confirmation test to prove your innocence. This test is much more expensive but is also virtually error free.

Subj: Tested positive for PCP
Date: 6/18/2006
I am on a Methadone clinic and I am allowed to take Clonopin by my Psychiatrist. I’m also a bad diabetic and I must take Humalog 75/25 twice a day and I take Lisinopril for high blood pressure, Nexium for a hyadal hernia and Lopid to cut the fat from my foods. Vitamin B6 and Valtrex for the shingles I recently got. Last week I was given an oral swab and it came up with PCP on it. This is the second time this has happened to me by swabbing. Is there something in my meds causing that to occur with PCP in my swabs. I didn’t even know what it was until my councilor explained it to me. I do not want to lose my take-homes, I worked too hard for them. What is going on. Can you help me? Thank you very much


AskDocWeb: We have no record of these products testing positive for PCP.

Subj: Interstitial Cystitus
Date: 6/18/2006
I have been ill for nearly 5 years with a disease called Interstitial Cystitus after following the removal of my right kidney for renal cell carcinoma. I take Elmiron and Piridium regularly. I had a severe urinary tract/ kidney infection for several months now. I have been fighting it with high doses of Ammoxicillin and treating the yeast infections with fluconazole. I had a procedure called a cystoscopy in which novocaine was inserted into my urethra 19 hours prior to a drug screen analysis. My bladder was not emptying completely and was retaining 25% of my urine and was extremely inflamed and the doctor had me take 2 Motin every 4 hours. The Ammoxicillin and fluconazple and kidney infection and novocaine and motrin and Elmiron and Piridium were all administered the day before a cocaine drug screen, which came out positive. As a result my daughter was taken away from me.
I believe I am a victim of a false positive drug screen for 18,000 ng of cocaine with a cut off level of 100 ng. Blood was also present in my urine by dip stick and my creatnine levels were 99 last February and 248 1 week after the urine testing was done but may have been higher at the time of the test. Help me please.


AskDocWeb: According to Blue Grass Drug Screen, Inc. Novocain may show up as a positive for opiates on urine drug tests. There is also a possibility that they used a cheap testing process called EMIT. This is far from accurate and produces too many false positives. We would insist on getting the more expensive GC/MS test to prove your innocence. This test is much more expensive but is also virtually error free.

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