Feedback on False Positives from Drug Testing, page 132

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: Bactrim false positive
Date: 4/27/2011
can bactrim come up as a false possitive for benzos an PCP i had a urin test with my PO today an she kept callin me a liar saying i was smoking meth an doing benzos i have never touched either one.


AskDocWeb: Urine tests do seem to have a problem correctly identifying antibiotics. ccording to reference 60 Bactrim may test positive for benzodiazepines. Getting a GC/MS confirmation test will clear up the question of drug abuse.

Subj: Positive for morphine?
Date: 4/28/2011
Can you help figure out a mystery for me? I am currently on 100mg of methadone at a clinic I go to. In the past few months I’ve shown up as being positive for morphine!?! I thought methadone couldn’t show up as an opiate, although I’ve been told that a persons liver or pancreas could be synthesizing methadone in some odd way? Is this true? I swear I’m not taking any other drug of any kind. Also, the levels have been off the chart with my latest being over 85,000 ng/ml!?!? My counselor told me that he didn’t believe the tests as I should be dead at that high of a level. Pleas help! I do have elevated sugar levels in my blood according to a recent doctor examine, high blood pressure and maybe early stages of diabetes, but unconfirmed. Thanks.


AskDocWeb: Let’s start by saying that we find it difficult to believe that a level of morphine over 85,000 ng/ml is possible from a living human body. Lethal ranges have been noted to be as low as 14,000 up to 81,000. Did you get the same result when the test was repeated?

Next, it may have been something you ate. Seriously, the poppy seeds you find on bread and pastries have shown up as morphine on urine drug tests. Depending on the source, the amount of morphine in the poppy seeds can range from 2 to 251 micrograms per gram. There more than two dozen medications that could cause a false positive for morphine.

As for the liver or pancreas synthesizing morphine, there is no doubt that some human cells can produce morphine. For example, if you use codeine the liver synthesizes or converts it into morphine as a natural process of metabolizing the drug. On the other hand the pancreas has been shown to produce morphine only when cancer is present.

Subj: Test for alcohol
Date: 4/28/2011
I tested possitive for ethyl sulfate level 141 cut off is 100. My creatinine level was 280.4 I I had Pneumonia the time of the test and was extrelely dehydrated. I am a 30yr old white female 5’8 ht and 117 lbs. Was this test innacuralty done? I have been told that the correct test, they would have added a formula of 100/280 and x it by 141. That concludes that the actual value ethyl sulfate is 50. 50 under the cut off of 100 concluuding the test to be negative for alcohol. Is this correct?


AskDocWeb: There is no way for us to determine which test they used but it sounds like what is sometimes referred to as “the 80 hour alcohol test.” Ethyl Sulfate (EtS) is a metabolite produced by the body only after alcohol has been consumed. The EtS metabolite is identified and quantified with Liquid Chromatography Mass Spectrometry, which can differentiate consumption vs. environmental exposure. This test can not be masked by illness and false positive results from diabetes have been eliminated.

Subj: False positive for barbs?
Date: 4/28/2011
Emergency… I take suboxone, xanax on rare occasions, zoloft and ambien recently switched from lunesta and I received a false positive for barbs?! can any of these meds cause that as I swear on my child who has passed that I have NOT ingested ANY barbs. Please help!


AskDocWeb: It seems likely that by barbs you are referring to barbiturates. If not, please say so. Xanax (Niravam, Alprazolam) has shown up on drug tests because it contains benzodiazepines (Reference 18) and Zoloft has shown up as a false positive for benzodiazepines (Reference 31) but none of what you list has caused a false positive for barbiturates.

Subj: You’re just guilty!
Date: 4/28/2011
i was recently drug tested at a pain clinic to make sure i am taking the medications morphine 30mg, soma 350mg, perccoset 5/325 and gabotin 900mg daily could this cocktail make me test positive for marajuana cause i did have a positive for thc and im not using street or medicinal marjuana! They let me go due to this im pretty mad cause they dont have to even check out a false positive ur just guilty!!!


AskDocWeb: Sorry to hear about your being let go Becky. As you may have found out, most clinics can write their own rules. However, none of drugs you list have been reported to cause false positives for marijuana.

Subj: False positive?
Date: 4/28/2011
I take suboxen and Cloznazepan and paxil. I recently had a false positive test that showed Nordiazepam, Temazepam, and Oxazepam. How is this possible? The test says its all in the benzo family but i have never heard of these much less taken them. Any explanations for this? I have been taken off my medication for this false positive!


AskDocWeb: We don’t have a listing for Cloznazepan. If you meant Clonazepam, that is a benzodiazepine derivative so it may not have been a false positive.

Subj: Oxycodone
Date: 4/28/2011


AskDocWeb: According to the Redwood Toxicology Laboratory, morphine sulfate tests positive for opiates (Ref: 33). Poppy seeds contain the opiates morphine and codeine, and can cause positive results on urine tests.

Subj: Positive for THC
Date: 5/1/2011
I was given a drug test at work, it showed positive for THC, then they sent it off for a gs/ms test. I was shocked that it came back positive for THC as well. I am not a pot smoker or do any drugs, I have had drug test like this in the past and they never was positive. The only thing that has changed is my wife has been cooking with hempseed oil & using hemp seed on sandwiches, salids could this have caused this. plesae help!!!


AskDocWeb: The plant that pot comes from is called hemp. Those who are subject to drug testing may want to avoid using products that contain hemp seed, hemp seed oil, or any part of the hemp plant.

Subj: Gabapentin (Fanatrex, Gabarone, Neurontin)
Date: 5/2/2011
I am looking for proof in writing that gabapentin (neurotin) causes false positives for Benzo’s… I called a pharmacy and they did confirm that the gabapentin causes false positives in certain urine protein test. My daughter was in rehab and has been released and now sits in jail for a false positive for benzos because of the meds she is on.. she takes 3600 mgs a day 1200 am 1200 afternoon and 1200 at nite. where can i find proof?? Thanks for any help you can give me.


AskDocWeb: It is possible that the pharmacy that you talked to gave you a quick answer without understanding what you wanted. Yes, gabapentin may cause a false positive test result but that result is for protein, not benzos. Gabapentin does not show “fail positive” in standard urine drug tests. The test that they were referring to is for protein in the urine, which is a warning sign of kidney damage or disease. Tests like the Ames N-Multistix SG or Chemstrip 3 dipstick tests may falsely show the presence of protein. It has nothing to do with testing for drugs of abuse.

Testing for protein in the urine is used to help evaluate and monitor kidney function, and to help detect and diagnose early kidney damage and disease. This may be done as part of a routine physical, a pregnancy work-up, as part of a hospital admission, when a urinary tract infection is suspected, or whenever there is a desire to evaluate kidney function.

Subj: Spirodex by Gaspari Nutrition
Date: 5/2/2011
i have randoms for my new job i just started and was wondering if any ingredients in a Gaspari Nutrition product ” SPIRODEX ” could show false positives?


AskDocWeb: The Gaspari Nutrition website does not appear to list the details about what ingredients are in this product. Since you have the product maybe you could share the ingredients listed on their label so that we can check them out. We would not purchase a supplement without knowing what is in it.

Subj: Accused of putting something in urine
Date: 5/4/2011
I’m not a drug user however a nitrite level of 200mcg has shown up in my urine that week I was taking echinacea cold and flu formula. My job is accusing me of actually putting something in the urine. can u help?


AskDocWeb: Sorry Chyna, often just the appearance of guilt can cause you trouble. The only suggestion we have to clear this up is to get a GC/MS test to identify what is actually in the sample. Masking agents do not fool that confirmation test.

Subj: False positives?
Date: 5/4/2011
I like to know if all these meds will cause false positives together. Simvastatin, warfarin, losartan hctz, viagra, metoprolol tartrate, kaon-cl, and omeprazole dr


AskDocWeb: None of those medications have been reported to cause a false positive, even when combined together.

False positive urinalysis for Oxazepam
Date: 5/5/2011
Dear AskDocWeb, I am writing in for a friend that had a recent experience with what she thinks is a false positive urinalysis for Oxazepam. She takes a prescription for Clonazepam & this also shows as positive in the test results, but after testing normally for over a year with this one Rx. showing, she suddenly started having Oxazepam in her test results. The tests are put through the GCMS and still show as positive for the Oxazepam.

The only change in her medication regime was that she was increased from 1 mg. Clonazepam to 1 mg. 2x a day. So her Clonazepam dose was doubled. She had no other benzodiazepine medications, but does take other medications like Hydrocodone & several other medications for diabetes & other health issues. Do you have any ideas about what might cause this test result? Thanks,


AskDocWeb: This has come up before so there may be something it. There are two anecdotal reports of Xanax showing up as oxazepam however so far we have not been able to document that as a legitimate possibility. The only other possibility we can think of is if your friend purchased their medication from an online pharmacy outside the USA. Some have been reported to switch or substitute one drug for another when they fill orders. That is another reason to buy locally.

Subj: Retesting came back negative and now cocaine?
Date: 5/5/2011
I am a 39 year old high school math teacher, and I am a patient at a methadone clinic where a drug test, in the form of a swab, is given once or twice a month. I became addicted to methadone after an accident 7 years ago that left my back broken in 2 places. I went to the clinic after realizing I could not have a prescription without taking more pills than prescribed. Inexplicably, I have had 3 tests come back positive for thc, a form of diazapam, and now cocaine!?. The first two tests were sent back for retesting at a different clinic at my request, and of course came back negative (I have never experimented with anything else, and I have never been a drinker or a smoker). I have requested a retest for this last test, but it could take up to 3 weeks for the results to come back! My counselor doesn’t understand why I am upset/apprehensive! How does this kind of mistake happen, and what kind of lab do they revert to, when they need to retest the sample? What kind of guarantee do I have that the other lab is better(?) Also, can my breath spray (I drink starbucks) cause a false positive or my amoxicillin???


AskDocWeb: You might check the ingredients in your breath spray against this list for possible causes. However, the antibiotic amoxicillin is known to show up on some tests as a false positive for cocaine (References 13, 16, 18, 20, 21, 26, and 29).

When a sample is sent to another lab for confirmation testing, that is typically a much more accurate test designed to rule out false positives. As for a guarantee, they are few and far between when it comes to drug testing. Your counselor should be able to tell you what lab they use for the additional testing.

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