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

Ordering Toxicology Screening Clinical Tips Drug TestingCATR: Dr. Stalcup, there’s plenty of variability in how psychiatrists order tox screens. How useful are tox screens, and when should we order them?

Dr. Stalcup: The tox screen is underused in psychiatric practice. A urine tox screen should be a standard part of all initial evaluations, because we know that drug use is a major confounding variable in psychiatric treatment. When you look at people who aren’t doing well, you often see two kinds of problems, both of which can be diagnosed with a tox screen. The first problem is that often drug and alcohol use is interfering with good outcomes in psychiatric treatment, and the other problem is unrecognized tolerance.

CATR: So how do we use drug testing for diagnosing hidden substance abuse problems?

Dr. Stalcup: I think of a tox screen as a diagnostic test. The defining characteristic of addiction is continuing to use substances in an out-of-control way in the face of adverse consequences. The question being asked by the testing is, in the face of adverse consequences, can this person not use? And if someone under scrutiny is unable to not use, then we feel that person should be evaluated for treatment of addiction.

CATR: Guide us through your process for approaching patients about drug screens. It can be an uncomfortable topic to broach.

Dr. Stalcup: There are very non-intrusive ways for us to get at drug and alcohol use without driving the patient out the door. If I’ve been seeing a patient for a month and I felt there was no progress, I might say: “How often in a month do you get a buzz?” Not how often they “drink,” because we are more interested in whether they’ll disclose intoxication. I’ll explain to them that research shows that drug or alcohol use might be interfering with what they’re trying to achieve in terms of symptom management. Testing is presented as value-neutral and a simple diagnostic screen. Despite this non-judgmental approach, some patients will be anxious and embarrassed, and if so I reassure them that no punishment will result from a positive test. When recommending the test you can say something like, “It’s part of our practice to get urine drug screens. We need to know what’s in someone’s system. If there’s nothing there, that’s good, and if there is, then we will talk about it.”

CATR: What do you do if there’s pushback from the patient?

This article originally appeared in The Carlat Addiction Treatment Report -- current coverage of topics in addiction medicine.
Want more, plus easy CME credit?
Subscribe today!

Dr. Stalcup: You may well get pushback and you say this is just a diagnostic test. We are trying to see what’s in your system so we can better design a treatment plan for you. I will share with them that sometimes it is hard to disclose what is in your system and that they are not aware that something they might be taking is interfering with their antidepressants and medicines. So while this can be a source of conflict, I’m surprised at how rarely it actually occurs. Sometimes patients are actually relieved they don’t have to tell us what they’ve been using. I try to roll with their resistance as best I can.

CATR: What about the specific case of an unwilling teenager being brought in by a parent for testing?

Dr. Stalcup: As with adults, we try to uncover the source of resistance. We ask, can you not use? Because if you cannot, it is very likely that your treatment is not going to go well. Patients, particularly adolescents, don’t like being controlled and the reality of drugs is that once you’re addicted, they control you. So we challenge them: if you can stop using, you’re in charge. If you intend to not use and are using, the drug is in control. Teens don’t like being told what to do and get furious and often fail the experiment. And then it opens the door to what they can do to evaluate and assess their use.

CATR: You also mentioned that a big reason for ordering tox screens is to check for unrecognized tolerance. What do you mean by that?

Dr. Stalcup: A common presentation in addiction and in psychiatry practice is a distressed patient, not benefiting from medication management; often they disclose a long history of sedative-hypnotic use (benzodiazepines, muscle “relaxants,” sleep aids, and alcohol). However, many patients are unaware of any problem stemming from their sedative-hypnotic use, and either don’t disclose their use or are reluctant to disclose the information for fear that the drug will be discontinued (which for many is a truly frightening process). In this context, a urine drug screen is a valuable diagnostic tool, and opens the door to more therapeutic options. It turns out drug withdrawal is highly kindled. Every time someone goes through withdrawal and it isn’t properly managed, the nervous system is sensitized (“kindled”) so that withdrawal gets worse over time. Once taken off of the sedative-hypnotic drug, these patients are often left with a high withdrawal symptom burden, and become refractory to medication management. We now know this is because of withdrawal management in which symptoms remain high during the detox and don’t remit after substitution medications are discontinued. I’m really troubled by quick and dirty detox. The drug is not the enemy so much as the withdrawal is the enemy, and we aim to mitigate that. A drug screen revealing benzodiazepine or sedative-hypnotic use can both help understand why the course of treatment is not going well, but also uncover a source of physiological and psychological distress to the patient. We feel strongly that psychiatrists need to look at unrecognized tolerance because it runs loose through so many psychiatric practices and is not that hard to diagnose. We strongly encourage people to rethink the issue of whether benzos might be contributing to treatment failure.

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?

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:

The Carlat Addiction Treatment Report
Click on the image to learn more or subscribe today!

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 July 21, 2019, from


Scientifically Reviewed
Last updated: 22 Mar 2017
Last reviewed: By John M. Grohol, Psy.D. on 22 Mar 2017
Published on All rights reserved.