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Opiate Testing


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An opiate is a medicine that contains opium, a naturally occurring narcotic present in the poppy plant. Law enforcement officials use opiate testing to detect the presence of codeine or morphine. Codeine is a type of pain reliever while morphine is a substance that is injected as it is in a metabolic state.
How Opiate Testing Works

Tests that screen for opiates use antibodies that the immune system naturally produces to bind to drugs such as morphine. However, this is not a fool-proof method as the antibody can also bind to other drugs or food particles that have a similar chemical structure to morphine. Other drugs that have a similar chemical structure include hydromorphone, hydrocodone, codeine and oxycodone. Screening tests detect varying degrees of these narcotics. These other drugs are addictive narcotics. However, a positive result for opiate can be caused by these drugs or even by consuming poppy seeds.

Limits for Testing

The Substance Abuse and Mental Health Services Administration is an agency that coordinates testing regulations on a federal level for opiate testing. Previously, the cutoff limit was 300 ng/ml. However, probation officers and others had a hard time assessing whether the patient had been injected with heroin or had consumed something else with poppy seeds. In 1998, the agency investigated new limits and established a new limit of 2000 ng/ml. This limit was intended to eliminate false positive results that occurred from the congestion of poppy seeds. Additionally, a new component of the test was added, which shows whether a metabolite of heroin is present. In turn, this shows whether heroin was recently used. It shows whether the person used heroin within a few hours of the time of testing.

The agency studied scientific data from over 1.1 million urine tests and over 317,500 specimens that were accumulated over approximately a one-year period. According to this information, 87 percent of all positive opiate results were later verified as negative by the MRO due to the use of prescriptions, consumption of food items, a lack of clinical evidence of prior history of heroin or other reasons. As such, the agency determined that the limits should be increased.

The agency concluded that there were too many false positives at the lower limit due to ingesting prescription drugs or poppy seeds found in food sources. Additionally, it concluded that adding the new metabolic element to the test would more accurately determine that a positive result would more likely be associated with the use of heroin.

Testing Indiscrepancies

The testing method is not flawless. There have been a number of reported indiscrepancies. In one case, two residents were tested after visiting a doctor. The first test showed a positive result of 150 ng/ml, showing a fairly low level of morphine and possible other opiate alkaloids. The second sample also yielded a positive result with a level of 300 ng/ml. Neither resident had a history of opiate use. Additionally, neither person exhibited other signs of opiate use. Due to these factors, the program leaders consulted with a toxicologist who stated that test results that showed a urine level under 5000 ng/ml was usually treated as a false positive derived from a food source contamination, such as from cakes, cookies, cupcakes or bagels. It was eventually concluded that the residents had eaten muffins with poppy seeds while they were on their way to the doctor’s visit and that the test was indeed false positive.

In another case, an employer had an applicant drug tested for opiates. Laboratories are not usually required to disclose to patients that certain food products can yield a positive result. The applicant completed a medical history form in which she listed all medications recently consumed. However, she did not make mention of any poppy seed consumption. When the test came back positive, the applicant explained she had consumed poppy seed muffins a few days before the test. She was told that she would not be hired and that she could apply again after six months. The applicant later sued the lab for breach of duty of good faith and fair dealing, negligence, defamation and tortious interference with a prospective contract.



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While every effort has been made to ensure the accuracy of this publication, it is not intended to provide legal advice as individual situations will differ and should be discussed with an expert and/or lawyer. For specific technical or legal advice on the information provided and related topics, please contact the author.

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