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Avatar universal

False negative drug screen

I am taking a low dose of Percocet 5-325 3x's a day, for chronic back and neck pain from a MVA. The problem is that even though I take it the way I should, I have had 2 negative drug screens.  What can cause this. Please help.

114 Responses
82861 tn?1333453911
It all depends on how much money the employer (or whoever it is that is forcing you to take the test) wants to spend.  A very good friend of mine works for a drug testing company, and there are many different panels the clients (employers) can choose from.  Some only look for alchol or marijuana; others look for everything they can afford.  

Since your meds are legally prescribed, there shouldn't be a problem.  Usually when you go in for testing you are questioned about what prescription meds you take, so if you listed the percocet, it wouldn't count as an illicit chemical on your test.  Also, the percocet is short-acting, so the level in your urine may have been too low for detection at the time you took the test.
246182 tn?1201378773
Avatar universal
    I am a nurse so I do know why the Doctors are the way they.  The answer is no I had not taking one before the test. I never know when the tests are to be done.

Avatar universal
Percocet is a synthetic opioid. In order to have a positive U/A a lab test called a GC/MS or Gas Chromotography/mass spectrography has to be done and the time from the last dose needs to be considered.
228936 tn?1249094248
No it is a semi-synthetic opiate and always gave me a opiate postive. all the best
Avatar universal
I am on a pain management program. The doctor just started testing for the presence of the prescribed medications, to my astonishment the results came back negative. We then three days later did a serum level and the same results. I swear on all that is sacred to me I am taking my medications as prescribed, but now because of thses tests I have been "cut off" I am having horrible withdrawel. I am trying to set up a lie detector test in order to prove that I have not in any way diverted, misused, or any thing else other than take my medications. I am so upset and I just can't understand how they could be negative when I AM taking all the medications. I am at the point as to why try any more. I have RSD I don't know if anyone here has this but it is impossible to live with. What can I do? I can't fo back to this kind of pain. The medications were the only things that kept me functioning.

HELP someone Please?

Avatar universal
I just went to the Dr yesturday and the same thing happened to me.. I went last month for a drug test and when I went to the Drs. this month He flat out refused to give me my meds saying that my drug test came back negative for any of the meds that I was perscribed. I like you take my meds all the time Unless I know that I have to drive and I told him that. But he still didnt want to hear it. I also have RSD and been on these meds for 3 years I have NO IDEA why they are not in my system. Im gonna end up going threw horrible withdrawl soon and Im scared to death.  Im on Methadone and Vicodin and He just Cut me off after one test comming back Negitive and I dont understand how it could. He called me a lyer and told me to never come back to his office. But there is no other Pain clinic in the area. WHAT WOULD CAUSE THE RESULTS TO COME BACK NEGITIVE when I TAKE THE MEDS????
356518 tn?1322263642
With so many people having this problem I have been doing some research....

It seems that these test have cutoff levels as in some are very sensitive while others are not sensitive enough to detect the drugs.

Dear triciatx-ga;

Thank you for allowing me an opportunity to answer your interesting
question. I am not a medically trained physician but I am a law
enforcement laboratory technician who routinely handles evidence
including specimens for drug screens.

A drug screen is a complex thing and the higher tuned (more sensitive)
it is the more complex it becomes. You see, drug screens can be
adjusted to detect various trace amounts of many different types of
drugs. Some test react positively for the presence of drugs
(substances or derivatives) only if those traces appear in the test
medium in certain volumes. For example, a person on parole may be
given a test for marijuana (cannabis, hash, etc) that will respond
positive if the test medium contains traces above  a certain “cutoff
level” where the cutoff level is very low (10ng/ml possibly) . Whereas
a person applying for a job may be given a test for marijuana
(cannabis, hash, etc) that will respond positive only if the test
medium contains traces above a certain “cutoff level” where the cutoff
level is very high (50ng/ml possibly).

There is some recent history with false results as is evidenced by
studies conducted by the Veteran’s Administration (VA). For example,
the VAGLAHS Outpatient Pain Program (OPMP) utilizes a standard Drug of
Abuse (DOA) immunoassay and Biorad High Performance Liquid
Chromatography (HPLC) Remedi-HS. These tests are used to monitor for
medication compliance. In 2004  as many as 44 % of patients tested
were found negative for opiates despite patient prescribed opioid
medication. The VA concluded that the DOA test was not sensitive
enough (in other words the cutoff was too high to detect the presence
of opioids commensurate with what the VA considered minimum
.‘Result of Urine Toxicology in VA Patients Treated In a Pain Clinic’

356518 tn?1322263642
I think my above post is saying that the test these Dr's are using are not the best for our situation. In order to test positive for our meds we have to have the required amount in our system that the test requires in order to test positive. If one test requires only trace amounts then surly there will be no problem, if one test requires that a high level be detected then we will have to have that level in order to test positive. Now to me this is outrageous that the Dr who orders these test can order the test that requires higher levels of the drug to be present in order to be positive, therefore some will and have failed these test. There is a member here that is a lab tech and can answer far more questions about this I will see if we can get him to reply.
Avatar universal
Hi all
I just posted this a while ago before I saw this one. I thought I would add it to the comments of this post as well.

I've been on pain meds for over 3 years. I take about 250 mg of OXY a day. I recently moved so I'm looking for a new Dr. I found one and took his initial drug test. The results so he claims are NOT what they should be. He accused me of diverting some of my pain meds. Even though I tested positive he said that the results showed that the levels of drugs did not coincide with what I am prescribed/ taking. Is this possible? Do they have the ability to detect the actual amounts consumed in urine? Aren't their a lot of variables involved that can influence this? For Ex. When I know I have to drive to the Dr.'s I do NOT take my meds that day until after I get home. Could this be why my levels were down? I always take my meds EXACTLY as prescribed, and believe me I need them. I would NEVER give them or sell them to someone else. Please help?
Avatar universal
I also would NEVER sell or not take my pills. The only time that I dont take my meds is like you when I know I have to drive. I have RSD and 4 hurnated disks in my back and a few deteriorating tisks.(how ever you spell it). And Like you Im in too much pain to not take my meds. But my (OLD) PM dr said that I dont take them and he stopped seeing me cause my drug test(urine) came up Negative. Im so upset about all of this. I havent been on my Methadone since weds. now. cause he wouldnt give it to me. And now he will not even see me anymore. My PCP did give me the vicodin that I was also taking but he said that he isent allowed to write the Methadone or he said that he would. I have been going threw withdrawls and I feel like ****. So I ended up calling the PM dr today just to explain my side alittle better,(seeing I was so upset when I went to him on thursday) and there was no dr in the office today. I also think that the antibiotics that I am put on every other month to every month for a kidney infection had to have something to do with the test results. I was told that Methadone can cause these infections SO there for I must be taking them, but the PM dr seems to think that Im not taking them. My PCP dr knows that I am taking them he believes me. I have never NOT taken my pills except for as like you Driving. I CANT drive on them they made me loopy... The meds that my PCP but me on to stop some of the withdrawl symptoms is working some what, The pain that I am in is HORRIBLE. I really need my meds back. I wish that drs didnt assume things and give ppl like me and you the benafit out the dought. Im not stupid I dont want to goto jail why would I hurt myself?
Again atleast your test showed something. Mine for some strange reason showed NOTHING. Did your dr still give you your meds? Or did he cut you off cold turkey like mine did to me? Mine wont even see me nomore. And there isent one around my area except for him.. I cant drive to the other one cause it is to far away from me. Where do you live?? Im in NY state, 80 miles from ny city. well I wish you luck with your dr, I know that its hard and stressful cause im kinda going threw the same thing as you.. Hang in there. Im trying and slowly slipping.
Wish there was something I could do. But Im also in need of HELP.....
Someone PLEASE help.......
501792 tn?1261111106
Hi Wonder and Babydm29,

        Wonder,  I hope you saw the reply I left you on your thread. I'm really sorry this happened to you both. If I could do something to help you both I would.
I know were all afraid that something could happen to our pain relief and am sorry both of you have to find out what it's like.
I'm not sure Wonder what your DR said this would mean for your pain treatment.  The meds did come up so maybe there is a chance however small that your DR will retest your level and give you another chance.

I truely feel for what your going through babydm with withdrawls. You must be in alot of pain. Is there any way someone could give you a ride to the one a little further away until your able to get your pain stabalized?
Or maybe once you have gone through the withdrawls your DR that gave you the percocets could help you with something else other than methadone until your able to find another pain DR.
They are helping with the withdrawls maybe they would go a step further for you.

I wish I had one of those magic wands that speeds up time until you both find another DR(if you need one Wonder)

Please keep letting us know how your doing. We'll be thinking of you.


Avatar universal
I don't live that far from my old Dr. and he still prescribes my Meds. THANK GOD. It's just a hassle to drive a hour for a prescription let alone the pain of sitting that long in a car without my meds. I was attempting to find a new Dr. Closer to home and he is the one who gave me the [email protected]#T. I was warned by my other Dr. that I might run into this because of the High dose I take. I think that the new [email protected]#H#@E Dr. just did not want to take me as a patient so he lied and used it as an excuse to turn me away. But I want to be sure so that another Dr. can't say the same thing. If anyone knows about these LEVEL tests please let me know. From what I've read so far I don't think that they even exist.


I hope that you can find some help. My Regular PM Dr. told me that I could always go to the emergency room for help if I really needed it. Just a thought.
Good Luck Hope that you feel better.

Avatar universal
i have no one that would give me a ride. Im suffering and my exPM wont even return my phone calls. The secretary there told me that he most likely wont return my calls either, cause he told me NEVER to come back to him. I have to goto my PCP on Monday. Im really hoping that there is something that he can do. I hate the ER here they are a bunch of ***** too. Well most of them are. When I mention the fact the I have RSD alot of them look at me like I have 10 heads and say ummm whats that??? Im loosing my mind. the withdrawls that Im having are bad. But like I just wrote to you my
pcp did give me something to help with the withdrawls it helps with
part of it, but not the really bad pain that im in. The pain that im
in now is 10 times worse then when I first started taking all of the
meds. Now out of no where I have a sever burning pain in my left
sholder on top of the RSD pain in my right leg and the back pain from
the degeneritive disk disorder and the hurneated disks in my back.
(sry my spelling really stinks). I have other withdrawl symptoms but
they arent that bad with the meds that my PCP gave to me. They are
still there but nothing like they were before he gave me those meds.
I called my PM dr today and the secretary took a message and said
that she is going to have him call me back, but I really dont think
that he is going to seeing he told me he never wanted to see me
again I really dont see how my PM dr can do this to me. I dont know
if anyone else in this group is from Ny state in the sullivan county
area that uses him as there dr, but if there is it would be really
nice to talk to you about this and see if he has done anything like
this to any of you. If by chance there is anyone in this group from
my area.. I really think that the meds that I was on when he took the drug test messed it up, but when I told my PM dr what meds I was taking besides what he gave to me he never wrote them down, or said anything about it .
Having RSD and all is bad enough. without having to add this into the
fight. I dont think that the drs realize the PAIN that we are all in
is real and will NEVER go away. I would never NOT take my meds I need
them to cope with everyday life. The only time I dont take them is
like I have said before I have to drive. And thats not much. mainly
only to see him or my PCP. Then I go right to the pharmacy and
stright home to take my meds and try to relax. I know that there is
alot of ppl out there that get them and give them away or sell them,
but im not one of those ppl. I really need them. I know in one of the
other chat places that I go into called MEDHELP. there are alot of
ppl talking about how ppl like us get F***ed over on our meds cause
of PPL out there selling them. that really never needed them to begin
with. RSD is REAL and so is all the PAIN that goes with it. I have
had it now for 5 years and these have been the worse 5 years of my
life. And now getting worse. Now with the withdrawls, having this
horrible burning pain(sort of feels like the rsd pain) in my sholder
and traveling into my back. I dont know what to do. I am gonna get
off of here for right now and try to relax. Im getting upset and im
starting to cry.
Hope that something can be done. Im going INSAIN..
Your friend
Avatar universal
I have been taking percocets for 7 years due to chronic pain.... i take up to 8 per day. I was just tested 3xs and they all came back negative.  Now I'm cut off by my doctor.. I don't know what to do
501792 tn?1261111106
Hi Help808

   I can only imagine how your feeling being cut off from your pain control, and I'm so sorry you are having to go through this.
  Were you taking them every day without missing any days in between?
If your UA is completely clean then you may want to think about seeing your PCP to start looking into reasons why this could be happening and looking for a new DR to help control your pain,
Were you seeing a Pain management DR?
I know there have been others here who have gone through this also and I'm sure they will be able to offer you some other ideas as to what you can do right now.
This seems to be something that is happening alot more than should be.

Avatar universal
I really think it has something to do with being on the meds so long cause I was on the Methadone for 3 years and I took 2 pills 3 times a day for 3 years and my test came up clean also. I really believe that our bodies must be so used to the medication that we are just getting rid of it way to quickly. Is that possable?? I really feel for you Help808. I too lost my dr and cant get my meds. Thank god with the Help of everyone here I am making it threw this. I have been dealing with this for over a month I even went as far as to writing my PM dr a LONG heart felt letter. Well I really dont know if he even read it cause I still havent heard anything BUT Im not letting it get to me. Im trying to keep my head up and think posative. I have to for myself and my children. Its a long hard battle that I have been going threw and I am really just taking it day by day and with the help of my friends on this computer Here in this group and in others that I goto. I did find a new dr Due to being in this group My PCP didnt even know the dr exsisted But I told him about him and that I found him threw my wonderful friends here in this group.. I believe that I told you all thank you for that. OH and I dont have to wait until October anymore to be seen. He pushed my appointment up and I have to go this thursday. Im just really worried that Im going to be pushed away, like the other dr did to me.. I know that I have to look on the brite side of things and think positive. Im trying. The ONLY bad part about pushing the appointment up to this thursday is that it isent in his office close to home but it is in his office that is alittle over an hours drive away.. But Im going to tough it out and drive there. I will let all of you know what happens.. Im going to see if he will do a blood test to check my drug test. And if the Meth is still there im going to send that in to my old PM dr.
Again Thank you all so much for being here when I needed you most. Im not saying that I dont need you all anymore. Trust me I DO.. You all supported me so much THANK YOU SOOOOO MUCH....
Avatar universal
Thank you guys!!! My Dr. told me he was going to send me to a pain clinic andso far nothing.   He won't even return my phone calls.  It feels almost hopeless but I'm glad to see that I am not alone
356518 tn?1322263642
I am going to start you a new post so you too can get the support and help that babydm29 did. She found a PM  to treat her and got the PM' referral from here at Med help! So hang in there and use her as an example that working on the problem and getting support does get results and we will help all we can. Please add some info to the new post so we can help:)
Avatar universal
I googled this topic and can't believe all the same stories I am reading here. I have been going to a pain mgmt specialist, though I use that term loosely and with sarcasm, for 5 years. For 5 years, I have been on 4 Vicodin-ES per day, for trigeminal neuralgia.  I moved here with this diagnosis established, having already tried and failed on many meds, and Vicodin-ES being the only thing that worked. I, too, have to take it every single day or I die from withdrawal symptoms. Having been on it so long, I have withdrawal symptoms anyway every single day after about 2 hours of taking a pill.  So, its been agony. Yet I never dare ask for any more or anything else. That's against the rules, if you know what I mean. Well, I, too, got a random urine drug screen, which I knew was coming for a long time, but I had not 1 ounce of fear or worry, as I always take my meds and never ever street drugs or anything. I don't drink or smoke. Totally boring life!  Well, my UA came back 100% negative for Vicodin as well and the you-know-what hit the fan.  I was stunned. They told me I must be stashing my supply and/or selling it. I was beyond stunned, to the point of tears. I stood my ground, denied it, and demanded to be treated for getting off these meds.  What do they do? I make an appointment to see the PM for Suboxone, having no idea or clue what it was. The guy gives me a dose that per my pharmacist would have KILLED me, most likely, and my insurance company agreed. Now I go back tomorrow to PM to return the Suboxone scrip unfilled, and request a slow wean off Vicodin.  This is NONSENSE. Why are we all testing NEGATIVE?  I've done a lot of research on Pain Management web sites for doctors, and they discuss that NEVER should patients, especially pain patients, be FIRED for 1 negative drug screen, that there are way too many false negatives. But I, like you all, want to know WHY we are testing false negative? I believe in the theory that we've been on these meds so long. That seems to be a common thread here.  I know I feel withdrawal symptoms starting about an hour or 2 after I take a pill. That's all the relief I get from withdrawal, so is it not possible that our bodies are metabolizing this stuff way faster than the average bear?? I am just like you all - I would die before I would not take my meds. I get SO SICK. Its preposterous to think otherwise.  Does anyone have any more statistics of this occurring?  Gosh, I really am sorry so many of us are having this happen. Its disgusting. I sit in the waiting room each month, and the skanks actually openly deal and exchange and sell their prescriptions, right in the office, and the receptionist could hear  - if she wanted to.  Also they get right down the hallway and start calling folks on their cell phones, saying they got their meds and will be right over.  Or they sell it in the parking lot. And I am the one who gets kicked out??? No way. By the way, I have also reported to the Nurse Practitioners that this is going on, and wonder if that's not why I'm the one getting the boot.  Stranger things have happened.  Sorry to carry on, but I am so amazed to find hopefully some friends here, who understand the horror and panic of this emotionally, let alone the physical agony.  
356518 tn?1322263642
I agree this is happening entirely to often! I too have done extensive research and there are a staggering number of cases and that is very troubling. Many of the members here have said they will get independent test done from now on because of this problem. What are the common denominators here? I have tried to tie cases together with similarities and have found very few. I have wondered myself if this is a way to weed out the Pt's the Dr wants to no longer treat? Once you have been 'fired' you will have a great deal of trouble finding another Dr wiling to take a chance on you. There are several members here that has had this happen to them and it is awful! I believe we should have to sign contracts so should the Dr and they should have to abide by the rules just as we do. We have no recourse when this happens and the Dr's will not re-test believing the false negatives are bunk. I wish they would see that this is happening too often and do something about it. If we were to ask for independent test when tested if makes us look guilty right off the bat by putting the thought in the Dr's mind that we think there may be a problem so we must be doing something wrong. It is a lose lose situation and luck of the draw. What can we do to keep this from happening , I really do not have any answers other than talk to your Dr about the fact that false negatives are happening alot and your afraid of this happening to you and educating everyone about the problem. As I said though I am not sure this is such a wise idea either as it may put suspicion on you.We have to walk a very fine line and it is a shame that we do have to but it is a combination of things that cause us to have do so.
The ones who purposely receive the Dr's and sell their meds are a huge problem to us. I have seen this going on too and it makes me so angry, we have such a hard time because of these jerks and I know in Fl they can get 25years min for such and offense. I have told my Dr when I have seen this happening and I assume he did take care of it as he does not want these kind of people in his practice either. You say you wonder if telling the practitioner about this caused you to have these problems, well that could very well be the case. I talk about the ones who abuse Dr's all the time but there are those Dr's who will prescribe to anyone and know they sell or abuse their meds but they do not care because they too are in it for the money. This is despicable and when these Dr's get caught they get a rally of support because it looks like they were convicted for helping genuine pain Pt's and got caught for doing so. Have you seen the video in our health pages about pain management and the problems we face daily?  The DEA is doing what they can to stop the abusers and dealers but in the process they hinder us and our Dr's as well. I really hope you can get some help with this, can you go to your PCP and get another test done today to show it either is a mistake or you have a problem with the meds showing up in your system. There are at least thirteen drugs that will cause false negatives too, I will find and post the for you later I have a appointment this morning.
I wish you the best of luck and will try and find some stats.
535089 tn?1400673519
A while back I posted a topic on Morphine Vs Negative Drug screen. It has some very informative info and also explains why the tests can come out negative. Scroll down a few pages and you'll find it or PM Beargizmo, I sent it to him. Take care
Avatar universal
i have had this happen to me on many occasion. taken my medicine not two three hours before test tell the tech show the bottle and blam negative. job interviews, government test dr test always negative and i take percocets a day for chronic pain failed back syndrome, sciatica and periphial neuropathy. in my case i am really high metabolized and have even bought the test from the drug to experiment with. my conclusion if i can feel the medicine working ie little to no pain then it will show on my test if i dont feel it ( 3-4 hours after taken ) and have previously used the restroom its always negative. the drs and new laws governing these types of things have gotten ridiculous, the people who need help cant get it while the seekers and pushers get what they want. its a flawed system but we as a pain suffering just have to deal with it west we can, in my case i binge on tylenol and asprin  i nkow i shouldnt but hey my meds are accounted for and they can do what they do. good luck to all
Avatar universal
I have been taking Clonazepam for about 8 years now,my doctor did a drug screen and it said that I had NO benzodiazepines in my system? my dose is 0.5mg every morning and up to 3 per day. Now my doctor has dismissed me!! Can anyone please help me with understanding why the benzos might not show up?
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