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Issues and Problems of Drug Testing

December 17, 2000
Related Topics: Substance Abuse, Featured Article
Drug abuse testing may seem fairly straightforward. And in the vast majorityof cases it is. But there are problems and controversies, which can complicatethe process and make it difficult to determine if a donor is abusing drugs.

Why opiates are different
For all the drugs in the DOT-5 panel, except opiates, the obligation ison the donor to prove his/her innocence. The donor must provide an explanationalong with supporting documentation as to why the drug or metabolite is presentin his/her urine. In a sense, the donor is presumed guilty unless he/she canprove otherwise.

With opiates, the situation is reversed. Unless the donor admits to use ofopiates, it’s the MRO’s obligation to prove the donor abuses the drug. Thisdifference exists because of poppy-seed ingestion and the complex nature of themetabolism of drug in this category.

There are three drugs in the opiate family that are tested for: codeine,morphine, and heroin. Codeine is broken down in the body into morphine; heroinis metabolized into morphine and 6-monoacetyl morphine. To confuse the situationfurther, poppy seeds are also metabolized into morphine.

A common misconception is that synthetic narcotics found in many pain pillswill cause a positive opiate test results. This is false. Many doctors aren’taware of this fact. A donor taking Percocet, Tylox, Viocden, etc. will not havea positive drug test for opiates.

When the D.O.T. first established the cut off levels for opiates, the levelwas low enough that a person who ate lots of poppy seeds could actually have apositive result. In order to lessen the likelihood of a falsely positive result,the regulations for verifying a positive opiate result are different from otherdrugs.

Urine cleansers
There are many products that claim to "clean" the urine of anydrug. In the past, many of these products worked. Currently most labs aretesting these substances, technically called "adulterants." It’s acat and mouse game - as the makers of the cleansers come out with new products,the labs add these substances to their list of adulterants to check the urinefor. The consensus is that most of these products don’t work any longer.

Dilute specimens
This is a hot topic in the drug abuse-testing world. Can a donor drink enoughfluid to dilute his/her urine to such a degree that an otherwise positive testbecomes a negative one? The answer seems to be no. The labs test not only theconcentration of the urine, but also for the presence of certain substanceswhich are always present in the urine no matter how dilute it is.

Witnessed collections
Some employers wonder about having every collection watched by the collectorto ensure the donor doesn’t try anything "funny." This is generallynot allowed. The DOT guidelines are very specific about this -- no observedcollections unless there’s a specific reason for it. Reasons would include arecent test that is dilute or when there is a suspected but not provedadulterant. Certain states and municipalities prohibit witnessed collections.It's best to steer clear of routinely witnessed drug tests.

The future
The latest development in drug abuse testing is POCT -- Point of CollectionTesting. With POCT, the screening test is done immediately after the urine iscollected. If the test is negative, then the process is over and the employerconsiders the results as final. On the other hand, if the test is positive, thenis packaged up following the same guidelines as for a regular drug test and sentoff for confirmation by the lab.

There's controversy over the use of POCTs. Although they seem to be accurate,the DOT hasn't yet accepted them for use in regulated testing. The DOT isevaluating POCT kits and probably will approve their use in the future.

The other area that's hot in drug abuse testing is the use of substancesother than urine. The biggest problem with urine testing is getting the urine.By using other specimens, such as hair, saliva, or nails, makes the collectionmuch easier. These tests have not been approved by the DOT for regulatedtesting.

Recent Articles by Richard Sagall, M.D.

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