Drug Testing FAQ

Updated 7/10/12.

Some clarifications to clean up the incorrect information circulating around in the wake of A.J. Allmendinger’s failed drugs test.  More questions – send them to admin(at)buildingspeed(dot)org and I’ll add them.

What Drugs are Prohibited?

NASCAR has a non-exhaustive list that includes:

  • Seven different amphetamines, including methamphetamine and PMA, a synthetic psychostimulant and hallucinogen.
  • Three drugs classified under ephedrine.
  • 13 different narcotics, including codeine and morphine.
  • Ten different benzodiazepines and barbituates.
  • Marijuana, cocaine, zolpidem, nitrites, chromates and drugs that can increase the specific gravity of urine.

Amphetamines are ‘uppers’, which decrease fatigue by increasing levels of the stress hormones norepinephrine (attention and responding/fight-or-flight reactions), and the neurotransmitters serotonin (modulates anger, aggression, mood, metabolism, etc.), and dopamine (increases heart rate and blood pressure).

Ephedrines are stimulants, appetite suppressants, decongestants. The molecule Ephedrine looks very similar to amphetamine. Psuedoephedrine is like the left-handed version of ephedrine and that’s what’s in over-the-counter decongestants like Sudafed.

Narcotics is an imprecise term that usually refers to anything that deadens the senses. Codeine, morphine, heroin, etc. fall in this category.

Benzodiazepines and barbituates are downers, which do the opposite of amphetamines and decrease the action of the central nervous system.

Zolpidem is a sleep aid found in drugs like Ambien).  Nitrites and chromates can be used to adulterate a urine sample and these substances have been used in the past to to try to cover drug use.   For example, the soccer player Hope Solo recently tested positive for a diuretic.  Diuretics would have not impact on performance; however , they can mask the use of other drugs and are therefore not allowed.  In her case, she took a pre-menstrual medication and was unaware that it included a diuretic.  She was let off with a warning.

“Drugs that can increase specific gravity of urine” is an interesting phrase. One routine check for adulterated samples is measuring the pH, temperature and specific gravity (the density of the sample relative to water) of the urine sample.  If the values are outside of the expected range, the sample is considered suspect.  This part of the rule isn’t about illegal substances, it’s about things that could hide the use of illegal substances. For example, if you drink large quantities of water (1-2 liters), most of it comes out in the urine and that dilutes anything else in there.

In typical NASCAR style, the list is non-exhaustive and those who are subject to testing are encouraged to check with NASCAR before they take anything.  reserves the right to test for anything they think could potentially impair a driver on the track.

Speed.com has a list from the 2010 rulebook.

What are ‘A’ and ‘B’ Samples?

Bob Pockrass has a very good summary of the process of collecting the urine sample, so I won’t repeat it here.   Splitting a sample into multiple parts is a standard testing protocol.  The sample is immediately split into an ‘A’ sample and the ‘B’ sample. The A sample is tested with a chemical test called an immunoassay. Immunoassay (IA) tests, as I’ll describe in a moment, are more general tests. The B sample is stored and there are specific protocols for how the sample must be stored. If the IA test shows one or more positives, then the A sample is tested using a more sophisticated test called Gas Chromatography-Mass Spectroscopy.

While companies guard against contamination zealously, there is always the possibility that someone grabs a pipette they think is new, but was already used for something else, or mislabels samples.  There are tons and tons of checks and balances in the testing system, but let’s say that this is the case.  That’s the reason for the ‘B’ sample.  The ‘B’ sample and the ‘A’ sample are identical:  the chances of someone making the same mistake twice are very small.  Allmendinger is allowed to have a representative present during the testing of the ‘B’ sample so that he has assurances that the procedure follows the standard protocols.  A trained toxicologist who is hired by the person being tested will be extremely picky and on the lookout for anything that might produce a false negative.

The GC-MS test is repeated on the B sample.  Often, only the test for the substance that was found is done because time is of the essence.  If the B sample tests negative, then the results from the ‘A’ test are voided and the driver is OK to proceed.   If the B sample tests positive, the driver has no recourse – he is out until he completes a substance abuse program NASCAR has designed for him.

How do the Tests Work?

Immunoassays work sort of like a jigsaw puzzle. There are antibodies (detectors) and antigens (targets). The two types of molecules bind to each other.

The molecule in the upper left of the picture above is our detector molecule. The circle represents something that can be detected – a fluorescent molecule, a magnetic bead or something similar. The molecules on the right-hand side are the molecules in the sample to be analyzed. Our detector molecule has a binding site – the fork pointing to the right, and that binding site will allow it to only link to specific shapes of molecules. (In reality, the binding is chemical, not by shapes, but I find the analogy to shapes easier to understand.) Our detector will only bind to triangle shapes, but there’s a problem here in that there are blue triangles and green triangles. Immunoassays are very sensitive – they’re good at detecting things, but they are not always as specific as we might like. The green triangles might represent a banned drug, while the blue ones are harmless – but both bind to our detector molecule.

Gas chromatography is a more sensitive test used to separate molecules by weight. The sample is run through a column so that all the molecules with the same weight as the target substance are collected. We demonstrate chromatography to kids in elementary school.  The analogy we use is to make two rows of kids the same length. Two kids are chosen to be ’sample molecules’. The first kids is allowed to just walk down the row. The second kid must shake hands with everyone in the row as he walks. We start both kids at the same time and, not surprisingly, the student who has to shake hands takes a lot longer to travel the same lengths as the student who doesn’t. In GC-MS, sorting is done by weight, so all the molecules with the same weight as the suspicious molecule are separated.

The molecules are then heated. All molecules break into fragments in rather predictable manner when heated, so the mass spectrometer detects fragments and you can infer what the molecule was before it was broken up, and how much of it there was.

Why not use GC-MS immediately?  It is more expensive and slower.

What are they Actually Detecting?

When drugs enter the body, they are metabolized.  Metabolized means that the drugs are chemically changed – broken down into other molecules or added to in order to form other molecules.  The rates and types of metabolize depend sensitively on the type of drug.  Amphetamine passes through the body into the renal system (the urine) mostly unadulterated by the body; however, other drugs are transformed by the body and what you test for are the products of metabolizing the drug. Some drug tests are therefore very indirect.

Could this be a False Positive?

A false positive is when your measurement indicates that the molecule you’re testing for is there, but either a) it isn’t, b) you’re detecting a molecule that looks like the molecule you’re testing for, but isn’t; or c) the molecule is there, but was not produced by anything on the list.  A lot of substances can cause false positives. For example, buproprion (an anti-depressant) can cause a false positive for amphetamine. So can an awful lot of other things.

However, the drug company asks drivers to provide lists of medication and the driver is given a chance to explain how the drug that was found might have gotten there through legal means.

Couldn’t A.J. Ask for a More Sensitive Test?

When we talk sensitivity, we’re talking about how much of a chemical can be detected.  You can’t detect a single molecule.  Different types of drugs (and their metabolites) can be tested for at different levels.

Blood tests are more sensitive for some drugs than others.  Hair tests have the ability to give you a longer term picture:  Drugs go out through the body in urine, but some are are embedded in the hair and remain there for a long time.

There’s two problems with asking for a more sensitive test.  First, they didn’t collect blood at the time of the urine test, which a week plus ago.  A test of current blood is an entirely new test and might not detect something that was there a week ago.  Hair doesn’t retain all substances, so depending on what drug they are concerned with, hair might not be an option.

Finally, some of these tests are much more sensitive, so if the drug was there in a less sensitive test, it’s definitely going to show up in the more sensitive test.

What is the Likelihood that the Lab Made a Mistake?

Regrettably, slim to none.  There are many checks and balances in the process – testing companies know that people’s livelihoods are on the line.  Given the high profile of this case, I suspect they ran multiple test to make sure.  If the B sample comes back negative, the testing company is going to have a major problem.  They must have had a very high degree of confidence in their results to release them and have NASCAR publicly take action.

Why Doesn’t NASCAR Identify the Drug that was Found?

Jenna Fryer makes some compelling arguments as to why NASCAR should identify the drug  publicly, but I’m a little more leary about crossing the line.  I believe it would be irresponsible for any details to be disclosed until the B sample is tested on the off-chance that the lab made a mistake.  The ‘A’ sample says “we have a reasonable enough suspicion to act”.  It’s like the proof you need to arrest someone.  For me, the ‘B’ sample is “proven guilty’.  Releasing any information until the ‘B’ sample is confirmed is wrong in my opinion.

Then there’s a privacy issue.  What if the drugs are legitimately prescribed and a doctor can make a convincing argument that a combination of drugs produced the positive test?  If a driver has mental health or impotence issues, should those become public because the treatment he is using caused a positive drugs test?

I suspect we will learn what the test results showed from Allmendinger’s camp because I can’t see how he restores his public image without being entirely transparent.  Compare the cases of Randy LaJoie and Jeremey Mayfield.  Randy ‘fessed up and said “I screwed up”, did what NASCAR asked and he’s back in their good graces.  Mayfield denied the allegations and tied up the matter in lawsuits.  He is in the midst of financial and legal troubles. Allmendinger can’t return to a racing career in any series without specifying exactly what happened, taking responsibility for it and completing the mandated rehab.  But I don’t think it is NASCAR’s place to release the information.

NASCAR has a very fair policy in terms of remediation and reinstatement.  The only time they shut the door completely is if you have multiple violations. If this was an innocent mistake (akin to the Hope Solo issue mentioned above), then it’s a simple matter of admitting you did something inadvertently and going through a bunch of counseling.  If someone has a substance abuse problem, the most important thing is helping them recover their health and their life.

NOTE:  Some of the information in this post was originally published by me on 5/15/09 on stockcarscience.com

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