Clinical Tips for Ordering Toxicology Screening: Q&A with Alex Stalcup, MD

CATR: You’re talking about people who have been on the same dose and it is not working for them anymore?

Dr. Stalcup: Yes. As tolerance develops to drugs, efficacy diminishes. Simple substitution/taper detox procedures may be effective in early efforts at detox, but if during the detox symptom scores remain high, kindling will result, with serious symptoms when abstinent, with shorter time to relapse. Tolerance reflects chronic up-regulation of the excitatory glutamate pathway. You can take away the benzodiazepine, but the glutamate pathway is still very active, and the patients are distressed, on edge, and irritable. The easy way to detect unrecognized tolerance is to say, “don’t use today. Let’s get your pulse and blood pressure tomorrow.” Uncovering occult or unrecognized tolerance can be a huge breakthrough, and it should be. One of our basic interventions, whether it is with teens or adults, is called the “experiment,” in which we ask them to see if they can not use for a specified interval, usually four weeks. Sometimes we’ll go further than that, especially with someone who we believe is really stuck on minimizing or denying their use. Empirically, we’ve found that we can uncover most cases of illicit or occult use with six tests in 90 days. The inability to not use when trying not to use is a defining characterize of addiction.

CATR: Once you’ve received your patient’s consent, how do you actually order the testing?

Dr. Stalcup: Most hospital and private laboratories offer drug testing services. The most common tests are urine drug screens, and laboratories will provide tests that determine whether the sample is valid; urine specific gravity, urine creatinine levels, and “integrity checks” are provided with the lab results. A urine creatinine less than 20 mg/dL suggests a deliberate attempt to deceive the test, and that itself becomes an important clinical issue.

CATR: Getting into some specifics, what tests should we order?

Dr. Stalcup: On the first visit, we order whatever basic blood work that might be indicated, but in addition, get a urine drug screen. The standard urine screen will reliably test for amphetamines, opiates, phencyclidine, cocaine, and marijuana. Laboratories offer a “comprehensive” drug screen which includes benzodiazepines, barbiturates, sedative-hypnotic sleep medication. Alcohol is the most commonly abused drug, but it is hard to test for because usually it is detected in urine and is cleared in 12 hours or so. Because of this, it’s important to ask for two important new tests for alcohol metabolites, ethyl glucuronide (EtG) and ethyl sulfate (EtS) with which many doctors are unfamiliar. Although most ingested alcohol is metabolized completely, a tiny amount of alcohol is subject to glucuronidation or sulfation, yielding EtS/EtG; a big advantage of this test is that these metabolites stay in the urine for about 80 hours after last use. EtS/EtG will give you a very, very accurate way of determining when the patient last used. It is a huge advance and we want psychiatrists to use it more often.

CATR: Is urine tox screen the most commonly used?

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Dr. Stalcup: It is, by far. However, we now have an increasing number of really good saliva tests, which can be done in the office. You can find out about amphetamines, cocaine, marijuana, opiates, and PCP. While you can’t directly test for alcohol in the saliva, you can get a saliva EtS and EtG and administer it in the office setting. Serial testing is essential to monitor if a patient agrees to attempt abstinence, since many patients are embarrassed or frightened to disclose that they couldn’t be abstinent when they were trying to be.

CATR: What do you do with patients who flunk the test?

Dr. Stalcup: The next step if someone is testing positive is to evaluate the four basic causes of craving—being around the substance, withdrawing from it, a mental health issue, and stress. If you think about it, those four causes of craving automatically lead to a treatment plan. So, for example, if someone has chronic withdrawal from clonazepam, they’re tachycardic (pulse greater than 90/min), their diastolic blood pressure is elevated (a diastolic pressure greater than 90mm/Hg), they have symptoms of anxiety, insomnia, agitation, and irritability. The “90 pulse, 90 mmHg diastolic” rule indicates a need for substitution therapy in which long-acting sedative hypnotic drugs like chlordiazepoxide (Librium) or phenobarbital are provided with meticulous attention to symptom control to avoid inducing kindling. Subsequently, tapering is conducted in such a way as to avoid a recurrence of symptoms, a “symptom-guided” taper.

CATR: What if the patient claims a false positive? Does that come up a lot?

Dr. Stalcup: Psychiatrists need to know that false positives are very, very rare. If you get a positive test the likelihood is extremely high they are using something. Also keep in mind you need to check for validity: urine specific gravity, urine creatinine, and pH. I had a 19-year-old who came in who tested negative. But there was no creatinine in the specimen and the specific gravity was that of water, so the sample he provided was essentially water. It turned out that he was using a Whizzinator.

CATR: What’s a Whizzinator?

Dr. Stalcup: A Whizzinator is a false rubber penis with a reservoir that you can fill with a liquid, and you look like you’re urinating from your penis. I was collecting supervised urine the other day and the patient’s penis fell in the toilet, which I can tell you is an upsetting way to end the day! Typically word gets out about Whizzinators and we’ll see three or four of them in a month. You can buy them online and they can be delivered overnight, but they fall off with regularity.

We recommend making a urine drug screen a matter of general policy as part of your intake work. Tell your patients that part of good medical psychiatric practice is knowing what’s in someone’s system.
~ Alex Stalcup, MD

CATR: There are various urine “cleansers” that people can ingest.

Dr. Stalcup: Yes, but most of those don’t work. A lab urine test can actually check for most adulterants. The ones that do work are usually diuretics, such as Lasix (furosemide). You can use a diuretic to fool a urine test, but if you look at the validity test, that person’s urine is abnormally dilute.

CATR: So it’s getting harder and harder for people to fool a test.

Dr. Stalcup: By far. We have patients who are trying to fool us, but we can do simultaneous saliva along with urine collections if there is suspicion of deception; that is usually the last time they try to mess with the test. Individuals who attempt to deceive a test represent some of the most severely affected addicted patients, and testing has indicated a need for formal addiction treatment.

CATR: Any new topics in tox screens we should know about?

Dr. Stalcup: The EtS/EtG is the biggest. The requirement that people look at validity tests is paramount and I think the emphasis on testing requires that the person ordering the test look at the validity test. They are not hard to understand. They will tell you “abnormal” right on the testing sheet.

CATR: Thank you, Dr. Stalcup. 

Clinical Tips for Ordering Toxicology Screening: Q&A with Alex Stalcup, MD

This article originally appeared in:

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This article was published in print April/May 2015 in 3:3.


APA Reference
Psychiatry Report, T. (2017). Clinical Tips for Ordering Toxicology Screening: Q&A with Alex Stalcup, MD. Psych Central. Retrieved on June 27, 2019, from


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Last updated: 22 Mar 2017
Last reviewed: By John M. Grohol, Psy.D. on 22 Mar 2017
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