Feedback on False Positives from Drug Testing, page 126

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: Adderal
Date: 3/21/2011
My son is taking aderal can it show a positive for methanphemine?? Please let me know Than you


AskDocWeb: Adderal is an amphetamine and may show positive for meth (Source: Physician’s Desk Reference, References 18, and 19).

Subj: Clean urine?
Date: 3/22/2011
I recently had a drug screen at work. I had stored some of my clean urine in my bag just in case I used and they gave us a random drug screen. The urine was in my bag for 2 weeks and came back positive for cocaine. They proceeded to send it to the lab. Can my old urine cause a false positive? I’m still awaiting results from the lab.


AskDocWeb: Sorry Nick, this forum is for those who do NOT abuse drugs.

Subj: Tested positive for Methamphetamines
Date: 3/22/2011
I am a parolee and did 5yrs….just got out. im part of a program called HOPE and have to call every single day to see if i test that same day. i went in friday after st patricks and tested positive for Methamphetamines? i dont know what happened but i havnt used for 5 years+…i tested negative just 2 days prior. on st paddys i ate corned beef & cabbage with red vinigar and had a red bull and some new gum called “5”….could any ingredient in these things could have caused this? i dont know but i had to do jail for 3 days and im curious for an explanation? Also the test was an instant one…they let it set for about 10 minutes. one more fact i took another one right after and it came out positive too! the only medication i take is Ranitidine for my stomach. if you can help it would be greatly appreciated. i dont want to go to jail again…

P. S. I dont know if you guys email us back or not….but i would like to inqire HOW ranitidine may come up as methamphetamines on a instant drug test from my parole???

AskDocWeb: The EMIT drug testing techniques provide high sensitivity but are limited when it comes to specificity. It appears that a metabolite of Ranitidine is cross-reactive because it is structurally similar to the metabolites of amphetamines/methamphetamines. Remember that urine tests are presumptive and according to most authoritative sources should be confirmed by gas chromatography/mass spectrometry (GC/MS). That should eliminate the Ranitidine as a false positive.

Subj: Diabetes or kidney problems
Date: 3/22/2011
Can diabetes or kidney problems cause a false positive for amphethamines, methanphetamines?


AskDocWeb: Diabetes has been involved in false positives for Amphetamines, Cocaine, THC, Ecstasy, Meth and Opiates (Sources: 3, 15, 16, 20, and 21). Kidney disease has shown up as a false positive for cocaine according to sources 3, 16, and 20. It is not clear if this is due to the condition or the medication used in the treatment of these conditions.

Subj: New hire drug screen for opiates
Date: 3/22/2011
I tested positive on a new hire drug screen for opiates yesterday and the only new medication I am taking is Celexa. I have never taken Celexa before and have always had negative drug screens. Everything else I take is the same-vitamin C-HRT-Glucosamin-Lysine-Vitamin D-Claritin and occasional Benadryl for allergies. How is this possible?


AskDocWeb: It is possible because the urine drug tests are known to have an error rate. That means a percentage of test results are not accurate. None of what you list is known to cause a false positive but that is not proof of anything. In order to find out if you have a false positive result you have to get a GC/MS confirmation test.

Subj: Rejected from job due to false positive
Date: 3/22/2011
Pristiq comes back as a false positive for PCP too. Any advice on who I would contact if I was rejected from a job due to a false positive?


AskDocWeb: A good start might be to inform the employer that the test is wrong and request a confirmation test be done to prove your innocence. Unfortunately many employers don’t or won’t do confirmation tests if a positive test shows up. Often this is because of the cost of the additional testing. You could suggest paying for this yourself by using a different testing service that meets with the approval of the employer. If the screening test is a false positive it will test negative on the confirmation test.

Another alternative may be to consult with an employment lawyer to get help protecting your rights.

Subj: How can I protect myself?
Date: 3/23/2011
I have been out sick for a week now. I attend a class that I get drug tested weekly for…and never have had anything EVER come up. But, I am afraid that with all the meds I have taken I am going to have a problem. My doc prescribed me azithromycin, valacyclovir, and fluticasone propionate nasal inhaler, and my albuterol inhaler yesterday. I was taking benedryl for my hives, robitussin, nyquil, actifed, and a throat spray with phenol, and a vicks nasal thing, the ones that burn your eyes when u sniff it in your nose, so, I go back to my class tomorrow…am I at risk for possibly coming up positive for anything. If so…what could come up?? And if it happens…how can I protect myself?? ANy help would be great!! Thanks in advance!


P.S. I have all the bottles and meds right in front of me to prove what I was on….does that help??

AskDocWeb: One way to protect yourself is to make and keep a copy of all prescriptions. If you are subject to drug testing and something shows up, you may be asked to provide proof of those prescriptions within 24 hours.

Another way to head off trouble before it starts is to keep a printed list of all the prescription medications that you are taking on your person at all times. If you are called in for a drug test, tell them that you are taking prescription drugs and present this list to the person who takes your sample.

Talk with your doctor about the possibility of your prescriptions showing up on a drug test. Just tell him or her that you are concerned about this and want to avoid any trouble. Knowing that you have done these things in advance may give you some piece of mind.

Subj: Gabapentin?
Date: 3/23/2011
I take gabapentin 300mg and got a dirty urine and came up as benzo is this possible?


AskDocWeb: Gabapentin has not been reported to show up on a urine drug test as a false positive. However, it is still possible because a certain percentage urine drug tests return false positive results. If you suspect the result is a false positive then find out for sure by getting a confirmation test. This is typically done with a gas chromatography/mass spectrometry (GC/MS) confirmation test.

Subj: Could any legal drugs cause a false positive?
Date: 3/23/2011
I was recently in the ER for stomach pain. I was given meds by IV and injections for nausea. Could any legal drugs that hospitals use cause a false positive for barbiturates?


AskDocWeb: Yes, there are more than a few legal drugs that show up on urine drug screens as false positives. You may want to check the list of what they gave you against this list.

Subj: Benzo acid?
Date: 3/23/2011
I was urine tested three times and found positive for cocaine but I don’t use it. The only medication I have been taking was excederin migraine pills. Could this because of the benzo acid in the inactive ingredients cause a positive?


AskDocWeb: No, benzo acid is not on the list of substances that might cause a false positive on urine drug tests.

Subj: Positive for MET500
Date: 3/23/2011
I resulted positive for MET500 im not sure if that is methamphetamine or methadone but i dont do any illegal drugs and never have the only thing i take is birth control could this have caused for this false positive?


AskDocWeb: The MET500 test is a test for methamphetamines that has a cut-off level of 500 ng/ml. None of the birth control pills currently on the market cause any problems with this test. Remember that urine test results are only preliminary and a confirmation test may be needed to eliminate false positives.

Subj: Urine test showed positive for marijuana
Date: 3/24/2011
i had a urine test done and it showed positive for marijuana, does ibuprofen, methadone or marinol have anything to do with it?


AskDocWeb: We found several sources that say both Ibuprofen and Marinol (Dronabinol) has shown up as false positives for Marijuana (THC) on urine drug tests (See: 1, 3, 16, 18, 29, and 48). However, these false positives were ruled out when a GC/MS confirmation test was performed.

Read more feedback about false positives:

Read Previous
This is page 126 – NextLast Page 300

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