Jun 13, 2009
With all the posts inquiring about false negative urine test I wanted to put this in my journal for reference.
When this issue comes up I always have to research the information so it is easier to just add it here in my journal. It is unacceptable that this is happening to anyone who religiously takes their pain medications. When they are tested and then fired because their test are negative for the medications they are prescibed it is unfair. there are too many variables to fire a patient on one negative test and the mistakes that can occur are too many to name. We need to have a contract with our docs just as they have with us only we need one assuring us they will not abandon us over one false negative result.
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’
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.
There are thirteen drugs known to cause false negatives in these test. I have posted them before and will find them and re post them. I am aware that a lot of people are having this problem and as you say it could be the labs but there's no way to know for sure. I would ask for a blood serum test.