Feedback on False Positives from Drug Testing, page 133

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: False negative
Date: 5/6/2011
i tested negetive for benzodiazepine(lorazepam/ativan) even though i take up to 4mg per day. do i need to request the doctor to use the gc/ms test or what because now he is threating to take me off of my ativan which is not good since it can bring on withdrawl symptoms. when i was in the office with him telling me this he said that i was selling my ativan and i pulled out my per filled daily reminder bottle and said why would i prefile this if i was selling them…i never knew that i was testing negetive..falsley 3 times!!! untill he just told me. I said i will take these right in front of you, come back in 2 hours and witness a urine sample with you and then have you( my doc) send it off for testing. I have a suspicion that its gonna come back false negetive again anyways. why am i getting false negetives…please help


AskDocWeb: The consequences of a false negative drug test are disturbing because it often results in a person’s integrity is being questioned.

Urine screening is not an exact science. One possibility is that the cutoff level for positive on the test is unintentionally (or ignorantly) higher than what is intended, therefore a negative result is being detected. If this is the case then you may be positive, just not positive enough to read positive on that particular test. You see a test designed to make sure that a patient is using all of their medication has to have a high cut-off point. The test would be useless if a patient could sell half of their dose to others and still test positive.

It may help to explain to your doctor that you want to do whatever you can to resolve this matter and make certain they understand you are distraught over this. Ask if they would do a blood test or hair shaft test and use the results to declare your urine test as incorrect. A blood test will show what is currently in the body and a hair shaft test can show that you have taken your meds in the past ninety days. Either test may be a good choice for those who have false negatives to prove their innocence.

Subj: Do dental anesthetics cause false positives?
Date: 5/6/2011
I recently tested positive at my probabtion office for benzos. I do not do benzos but i was recently under anesthesia at my dentist office to have some teeth removed. Would that cause me to have a positve test? The anesthesia was two weeks or little over two weeks.


AskDocWeb: According to Blue Grass Drug Screen, Inc. Novocain may show up as a positive for opiates on a urine drug test but not for benzos.

Subj: Serious moodiness
Date: 5/6/2011
I have been on ortho tri cyclen lo for over a year and a half and in the past 3 or 4 months i’ve notice some serious moodiness. When I get mad it happens in a flash of a second and its really hard to get it under control before next thing i know im crying because im mad at myself for getting so irritated for almost and usually no reason. hope this helps! T


AskDocWeb: If any side effect becomes an issue or disrupts your daily life, talk to your doctor.

Subj: I tested positive for cocaine metabolites
Date: 5/6/2011
I am very concerned as I tested positive for cocaine metabolites yesterday (nothing was specified in the lab report, such as how much or which metabolites were detected). My doctor admitted the results were unclear and poorly written. Now, I have to spend $700 on a urine drug test that’s more accurate. They are using a mail-in lab for an Amber Tox “because it’s more accurate”, even though my doctor said the results were very unclear in the lab report.

I do not and have never done any illegal drugs, nor am I around them. I take Oxycodone 10mg without any tylenol or ibuprofen, Fentanyl Pain patch 12.5mcg, Soma 250mg, Xanex 0.50, Lunesta 3mg, Power to Sleep PM (over-the-counter sleeping pills), and Provigil 200mg. I have a disease and therefore lay in bed all day long. My question is, does this sound rational to anyone else? I feel set up in a way. I have taken drug tests for the last 3yrs and every month they were perfectly fine….It showed I was taking my medicines as prescribed and no other drugs, especially illegal drugs. Wouldn’t it be more logical to have my urine retested at that same lab in my doctors office (because my insurance pays for it there) or at least contact the lab and ask them what the results mean since my doctor was confused about the report, instead of making me pay $700 for another urine test? Does this sound unusual to anyone else? Having your patient take a $700 drug screening test when my doctor doesn’t even understand the results on the lab report himself?

It clearly states on the lab report that the above medications were in the patients system: opiates. Then below that, it listed approximately 12 other things. Some of them had two astricks (sp?) like this ** next to them and a few others didn’t. Cocaine was one of the few with the two ** next to it. Below the 12 listed medications and cocaine metabolites, the report stated: **the following drugs have been reported.

The part that confused my doctor was the drugs with the ** next to them weren’t listed above under: The following drugs were found in the patients system. Anyhow, I am also wondering if I can sue the lab for creating an unclear report or for saying I take cocaine (because they put two astricks (sp?) next to cocaine metabolites).

I’ve never sued anyone before, but I am having to now pay $700 for someone else’s mistake. Also, I’m getting ready to go through a divorce and I do not need that on my record. My mother-in-law went to the same doctors office for along time because she has Fibromyalgia and last year she tested positive for methamphedimines twice in a row and they refused to prescribe her medications afterwards. I know the doctors there don’t like prescribing pain meds and get a lot of heat when they do prescribe them or so my doctor has said in the past. So a part of me thinks maybe they are setting their patients that have to take pain medications up for failure. Has anyone heard of this before?


Subj: How can I clear my name?
Date: 5/6/2011
I recently tested positive for cannabioid and the level was 97. I don’t smoke marijuana or hang around people who do. I do drink a tea called Melisa. Would you have any idea why the result came back positive for cannabinoid or what it can be from so I can clear my name. Also how high is a level of 97? I believe is it measured in ng/ml. Thanks.


AskDocWeb: The cutoff level on the standard urine test for marijuana metabolites is 50 ng/ml so 97 is nearly twice the amount needed to test positive. The “ng/ml” stands for nanograms per milliliter, which is a measure of concentration. The possible causes of false positives that we know about are listed here. As for clearing your name, in most cases that requires a GC-MS confirmation test. The cutoff level for the GC-MS test is generally 15 ng/ml so if that test doesn’t show any marijuana metabolite then the urine test will be considered a false positive.

Subj: Liver and kidney disease
Date: 5/9/2011
how does liver and kidney disease cause a false postive in a drug test?


AskDocWeb: The pharmacokinetics of this are not yet understood, just that it does occur on urine drug tests.

Subj: Positive EtG result
Date: 5/10/2011
I have been told that i had a positive etg result after abstaining for near 3 months. I am a gastric bypass patient and am trying to figure out how I am going to fight this! I have found where certain foods can trigger a false pos (ie wine/balsamic vinegar). Any help would be much appreciated!


AskDocWeb: For those unfamiliar with EtG testing, it is a test for the presence of alcohol. Please note that balsamic vinegar has an alcohol content that ranges from 3% to 6% so if that was the cause, the test result was not a false positive. Ethylglucuronide (ETG) is a metabolite of alcohol that is produced by the liver for 3 to 5 days following ingestion of alcohol. Here is a list of items people have said that they consumed prior to receiving a positive ETG test result.

Sterling Reference Laboratories states that the EtG (Ethylglucuronide) is a sensitive biomarker of ethyl alcohol exposure and that a low-level positive EtG could result from sources other than beverage alcohol. A low level test result may be termed an innocent positive if it is believed to be caused by other sources.

Subj: Cephalexin?
Date: 5/11/2011
Will Cephalexin cause a positive result for Cocaine?


AskDocWeb: If you have diabetes, you may get a false positive result for sugar in your urine but Cephalexin has not shown up on urine tests for drugs of abuse.

Subj: DMAA based product?
Date: 5/11/2011
Subject: DMAA in thermogenic product, causing positive urine test for Amphetamines???…Help.. I’ve been subject to weekly and random, urine Emit tests for the past year. (Yes, misdemeanor probation) Zero, substance abuse and zero positive test results.. Until last week. I tested positive for Amphetamines. It’s emotionally draining as I know, that I have NEVER even come close to taking anything like that, especially in the past year!

I did start taking a Thermogenic product that was DMAA based approximately three weeks ago, which included a week of light usage before taking the recommended dose.. The urine sample is now back at the lab, undergoing GS/MC testing for confirmation of whatever the chemical is that created the false positive. In the interim, I feel helpless as I can’t identify the source of the positive test result. My dietary intake is largely fish and clean carbs. That and I’m probably somewhat dehydrated as well, day to day.. That’s it! Nothing else! I believe the culprit is the DMAA based product, but I still don’t know what else could account for it??


AskDocWeb: According to an article published by the U.S. National Library of Medicine DMAA (dimethylamylamine) may indeed cause a false positive for amphetamines. Here is the quote from the Journal of Analytical Toxicology, April 2011:

“Recently, the DoD laboratories have observed a significant decrease in the confirmation rates for amphetamines because of specimens screening positive by two separate immunoassays and confirming negative by gas chromatography-mass spectrometry (GC-MS).” … “Additional information obtained from an immunoassay vendor suggested the anorectic compound dimethylamylamine (DMAA) may be the cause of the false-positive screens. An additional 134 false-positive samples were received and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS-MS) for DMAA. LC-MS-MS analysis revealed the presence of DMAA in 92.3% of the false-positive samples at a concentration of approximately 6.0 mg/L DMAA, causing a positive screen on both immunoassay kits.”

Source: Division of Forensic Toxicology, Armed Forces Medical Examiner System, Armed Forces Institute of Pathology, 1413 Research Boulevard, Building 102, Rockville, Maryland 20850, USA

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