View Full Version : Oxycodone False Negative Urine Test

Sep 2, 2009, 09:25 PM
I am having trouble with my pain management doctor stating that I am not properly using medicine which he has prescribed. He performed a urine test and it was negative in both the office and in the lab. I am certain that this is incorrect and cannot explain what is happening. Can you offer an explanation? Help!

Sep 2, 2009, 10:42 PM
Not sure I can, but oxycodone, oxymorphone, hydrocodone, hydromorphone are very similar in pronunciation.

Is it possible that the wrong test was ordered?

I'm kind of surprised that he wasn't testing for other painkillers, not the one you are on.

Can you offer what how much drug you took prior to the urine screen and how long before the urine screen was the test after dosing?

Reminder that oxycodone is Oxycontin. Was it the SR/ER version?

From the Prescribing info:

Oxycodone is extensively metabolized
and eliminated primarily in the urine as both conjugated and unconjugated metabolites. The apparent elimination half-life of oxycodone following the administration of OxyContin® was 4.5 hours compared to 3.2 hours for immediate-release oxycodone.

What that says is that it will be gone in 5x times 4.5 hrs or 3.2 hrs. This also depends on your metabolism.

please help me???
Mar 10, 2010, 03:03 PM
I was recently UA tested for Oxycodone. My test came back negative, the test papers said - U Oxycodone Lvl: Oxycodone detection limit 100ng/ml.
I am taking 10mg Oxycodone every 12 hours. The test was taken almost exactly 12 hours from my last dose. I cannot tell you what kind of trouble this has caused, that is until after seeing how many other people have had this problem. What level should someone taking my dose show on a test?? Please help!

Mar 21, 2010, 11:45 AM
Oxycodone (OXY) is a synthetic opiate marketed as Percodan, Percocet, Roxicodone, Oxycontin, etc. Although classified as an opiate, the chemical structure and metabolite of OXY requires a separate test with a substantially higher sensitivity detection level than that of the standard opiate drug test.

Federal requirements (SAMHSA) establish 2000 ng/ml sensitivity (cut off) level for the standard opiate test and at this threshold OXY would not be detected. OXY tests require a cut off 100 ng/ml.

Your doctor may not know this. Labs should but errors are too frequent. It sounds like this error may have occurred in your doctors office and was simply transported to the lab by submitting the wrong kit or requesting an opiate (as opposed to OXY test). This is not uncommon on the part of physicians. Review the paperwork.

Mar 21, 2010, 12:31 PM
I was recently UA tested for Oxycodone. My test came back negative, the test papers said - U Oxycodone Lvl: Oxycodone detection limit 100ng/ml.

The proper cut off (100 ng/ml) was used on your assay. However, OXY has a clearance time with a minimum of 1 hr to a maximum 1-2 days. That is an extreme variance in detection and clearly indicates that at 12 hrs it may have been eliminated. Also 10mg is at the lower end of dosage.

Jun 3, 2010, 03:37 PM
I had a negative test too an I know how bad it makes you feel I nearly had nervous breakdown when I was accused of selling my meds I am on oxycontin 40mgs and I take 12 of them a day and mine didn't show up I was shocked these doctors out here should do research before labeling someone a supplier to the street market I found this very rediculas and seek to fight this negative outcome if you are having the same problems do some research print it all out an take it to your doctors this honestly made me very upset good luck guys also there's certain circumstances to a negative you could have a very fast metabolism or an enzyme in your body producing a negative good luck guys

Jul 19, 2010, 03:29 PM
I just had a test that said I was not taking my meds percocet either! Now I am supposed to go to an addictionologist and prove I am not an addict?? Or they are taking me off my medications that I desperately need for my severe chronic pain. I am stunned

Aug 25, 2010, 12:41 AM
This same thing just happened to my mom... can't figure it out!

Sep 20, 2010, 06:07 PM
WOW! Add me to the list of negative testers. I'm being retested @ 2 week intervals till its stable. It really sucks to have to go to a pain management doc in the first place, anyone you mention it to labels you. Pharmacists label you too. The only thing I have found helpful was that if you are thin and drink Lots of water it can dilute. Since I am borderline diabetic, I drink about a gallon of water a day

Sep 20, 2010, 10:36 PM
False positive/negative drug tests. What you can do. US only

Congress passed the Clinical Laboratory Improvement Amendments (CLIA) in 1988 establishing quality standards for all laboratory testing to ensure the accuracy, reliability and timeliness of patient test results regardless of where the test was performed. Enforcement has been lax due in large part to a lack of awareness on the part of the public as to their rights in the testing process.

The drug test you are given is no better than the test used (and they vary widely in accuracy) and/or the qualifications of the laboratory and technicians performing the tests (even more varied than the tests).

If you feel that a drug test was inaccurate you can take the following action:

First, in writing, protest the inaccuracy of the test to every person and agency or organization involved in the testing process. Do not go into great detail. A statement that “the test was inaccurate and damaging” is sufficient. In that correspondence request the complete identification of the particular test used, a. brand name and b. CLIA and/or FDA certification number for the test, and request the c. laboratory certification number for each agency or organization involved in the testing process and d. the chain of custody form (COC). [Each person that handled your sample had to sign this] The COC is a very important document. If it is not maintained the test is without value. If it was handled by unqualified individuals you can determine that.

If you already know the name of the testing agencies (ex. Physician, laboratory, etc) you can check their certification by going to:

LABORATORY LOOKUP (http://www.cms.gov/CLIA/20_CLIA_Laboratory_Demographic_Information.asp#Top OfPage)
You can lookup any laboratory by a. name or b. Ten digit ID number or by c. region at this website.

Once you identify the laboratory(ies) involved you should send a copy of your complaint to the CLIA Regional Office for your region. You can get that address here:
CLIA REGIONAL OFFICE LOCATOR (http://www.cms.gov/CLIA/downloads/CLIA.RO.pdf)

A copy of your complaint should be sent to your state agency responsible for laboratory regulation. The responsible agency for your state can be found at:
STATE REGULATORY AGENCIES (http://www.cms.gov/CLIA/downloads/CLIA.SA.pdf)

Certain tests do not have to be certified by CLIA but still must have an FDA waiver. These are mostly the tests sold for home/personal use. Usually available by mail or OTC. You have the right to know the brand name and identification of any test that was performed on you. You can then check the test against the Federal Drug Administration list to see if it is exempted, and for what uses, at
TESTS WAIVED BY FDA (http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfClia/testswaived.cfm)
Note: Drug tests are exempted for specific reasons. It is not a blanket exemption. Most of the waivers are issued for home use only. Some companies may order home drug tests and use them for in-house employee drug testing, for instance. That is not allowed. So look up the test and also read the FDA waiver restrictions.

File your complaint with other accrediting agencies. CLIA sometimes delegates accreditation to one of 6 other approved organizations (ex. College of American Pathologists). So the lab may be certified by one of these other agencies, in which case a complaint would also be filed with that organization. Those 6 agencies are listed here:
OTHER ACCREDITING AGENCIES (http://www.cms.gov/CLIA/downloads/AO.List.pdf)

Even if it is certfied by another approved regulatory body, send an information copy to the CLIA Regional Office and the other agencies listed above.

You can check on any past legal actions taken against a certified laboratory at
LABORATORY REGISTRY (http://www.cms.gov/CLIA/18_Laboratory_Registry.asp#TopOfPage)

Dec 30, 2010, 01:13 PM
I had the same problem and my Dr. did some digging of his own along with the Pharmacist and they found out because these medications are opiads not opiods that you have to have a 10 panel drug screen instead of the standard drug test or the 5 panel test due to the half life of the opiads. I hope this helps those of you that were in the same situation that I was in.

Aug 11, 2011, 11:27 AM
I am a pain mgt. patient and have been for 3 months short of 5 years. I have been tested (blood and urine) for confirmation of my medications the entire time, I have never tested without my medications. Up until the switch from the OC formula of Oxycontin to the OP formula. The switch occurred approximately 6-7 months ago, 4 or 5 months ago is when the doctor began the testing. (And PS I am a person who agrees that the two are not as effective as claimed. Which hurts the quality of my life dramatically. This is a totally travesty for us in pain.) Each test I took gave false negatives!! This was horrible with the doctor. Who then asked me if I had started selling my medications!! Since this time he has gone back and forth between cutting me off my meds or leaving them the same and trusting me. As of now he has settled on reducing me and (from what I can tell) completely taking me off my pain meds. Including my methadone that did show up in these tests regularly. I have been with this same doctor for 4 years and he still questioned my proper use of my meds. I have tested positive twice during this time, once was when I was able to have my 40's filled as OC's the other was when I was given instant release Oxycodone 30's. I have explained all this to the Dr. but this has not affected his decision. He tells me that it is not possible to get a false negative if I am taking my meds but I AM! Please anyone else with this same problem please speak up and lets figure out what's happening, why its happening, what can be done about it & lets do it fast. People are hurting and this makes EVERYTHING worse! Cencen I feel your pain (or at least I can relate). I am not sure this is an answer but it will hopefully let you know your not alone with this problem. I wish the best to everybody and pray that resolution can come swiftly to this issue. I pray for proof to be provided by a reliable source that we are not liars, cheats and or addicts we are just people who are suffering due to a pharmaceutical screw up!! If you find proof please post it!

Aug 11, 2011, 02:21 PM
Your problem with the effectiveness of Oxycodone OC v OP is well documented and should be reported to the FDA.

FDA's MedWatch Program at 1-800-332-1088.

The OP version was inadequately studied, under unrealistic protocols* and has been causing problems for both doctors, who were advised only by the manufacturer, and of course the patients are bearing the brunt of the switch. Here is a website, with many links to concerned agencies, that also has user reports:

MD Junction (http://www.mdjunction.com/forums/fibro-challenges-discussions/medicine-treatments/1943996-old-oxyoc-vsnew-oxyopyour-opinions-please)

*See Pharmacy Advice (http://www.getpharmacyadvice.com/oxycontin-op-vs-oc/) for a thorough description of the tests performed or you may access the pre-market tests directly at:

Clinical trials 1 (http://clinicaltrials.gov/ct2/show/NCT01101308?term=reformulated+oxycontin&rank=8) an FDA site, or

Clinical trials 2 (http://clinicaltrials.gov/ct2/show/NCT01101321?term=reformulated+oxycontin&rank=7) also FDA

This doesn't answer your question about testing. I am looking into that. The release mechanism and peak effectiveness are slightly different but I can't say with certainty that those factors will influence the test. Other than that, there has always been a problem with detecting Oxy and Hydrocodone (semi-synthetics) due to test methodology and/or variable metabolism.

Jan 20, 2012, 01:32 PM
Hi I've recently took a urine test and a blood test. Both of which have come up negative. I can take 2 5mg oxycodone which amounts equal taking 8 pills a day (80mg). My doctor sent a certified letter sent stating that I had 30 days to get a new doctor, and he wouldn't be filling my medications any more. After the taunting research and going back in several times, I talked him into another urine test. I took two of my oxycodone in front of him and made sure that I was given the same urine test. I waited about 25 minutes before I took the test to make sure my drugs were in my system. Guess what that second test came up negative as well. So as soon as I went back to see him for my results, he gave me refills on my oxycodone. See here's the thing I knew I wasn't selling my pain medication in any shape or form. But with research I got answers, which should have came from my doctor. Urine test for oxcodone will show up negative every time with the regular test they do. You must make sure they test your pee with a GC Mass Spec. It is a very expensive piece of equipment. Also with the regular pee test they take in hospitals and most medical offices they look for opioid levels from 120mg-300mg. That right there is an over dose. Check this article out and it explains it all, better yet print it out and go to your doctor and make them read it. Www.healthboards.com/boards/pain management/311582-false-negative-urine-test.html I hope that helps someone out, though I am baffled about my blood test being negative ,and lab it was sent to suposely used the GC Mass Spec. test. If anyone could help me with reasons it came back negative that would be great, oh and also my Doctor sent another blood sample and sent to lab for same testing.

Oct 27, 2012, 11:57 AM
I am taking Exalgo ER 16 Mg I take two every day. When I was given a drug test and it came back negative and I know this is not correct. The doctors office is saying I selling this drug. I can do that I need this medication for pain. I am very upset about this. The way they test is with a swab. Please help.

Oct 27, 2012, 11:58 AM
I take Exalgo Er 16 mg but it will not show up in my drug test, please help. Something is wrong.