Crucial Confirmations: The Importance of Lab Testing in Drugs of Abuse Screening

Crucial Confirmations: The Importance of Lab Testing in Drugs of Abuse Screening


While instant urine tests for drugs of abuse have improved tremendously over the years, the simple fact that it is still just a method of screening tells us that there are some limitations in the amount of information that they provide. Here we will discuss some of the obvious (and less obvious) reasons why laboratory confirmations should be considered a crucial part of your testing program.

First and foremost, it is part of the manufacturers’ instructions for use; usually worded to the effect of “This assay provides only a preliminary analytical test result. A more specific alternate methodology must be used in order to obtain a confirmed analytical result. Gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) are the preferred confirmatory methods”. If I provided no additional reasons beyond this, that it is listed as a “must” in the instructions is a pretty compelling argument.

Let’s discuss some of the reasons that test manufacturers (and the FDA, whose guidance compels these instructions) find this so important…

Firstly, it is no secret that drugs screens – whether an instant device, or a “desktop analyzer” type device – are not 100% accurate. While most panels on our instant tests are greater than 99% accurate, it is this remaining 1% that needs to be accounted for. A good example of this is known cross-reacting substances; using the Fentanyl panel as our example, we know that the medication Buspirone (Buspar) can cause a false positive on the Fentanyl panel. The only way to be sure that the positive result is due solely to the Buspirone would be to have the specimen confirmed via laboratory. There are no cross-reactions on a laboratory confirmation.

Another reason lab confirmations are crucial is the fact that most of the panels on an instant test react with many substances within that drug class. An example I like to use for this instance would be the Benzodiazepine (BZO) panel. Let’s say you have an individual who is prescribed Alprazolam (Xanax), but maybe you have suspicions of other Benzos being used. You would expect to see a positive BZO due to the Xanax, but only a lab confirmation could determine if the positive was from the prescribed BZO, or a different BZO that may have been taken illicitly.

Levels in urine tests don’t provide much (if any) useful information, with one exception: checking for THC level over time. Of course, all instant screens are qualitative (positive or negative) and cannot provide a quantitative result (level). In this instance, with the lab confirmation providing the quantitative result, you are able to check for THC level over time to monitor continued abstinence.

Lastly, I’m sure you have encountered outright denial of use, at least on a couple of occasions; something to the effect of “that can’t be right”, or “your tests are broken”, where they are hoping by some miracle the lab result will confirm their story. Of course, some will admit use after the results of the instant test, reducing the importance of confirming. The other side of the coin here is someone admitting use where nothing shows on the instant. In these instances, the lab will confirm at a lower cut-off level, and will typically show that the concentration of substance was just not high enough to react on the instant.

In summary, while the use of instant tests is a hugely beneficial tool, it can’t always tell the whole story. They do reduce the lost time and cost of having to send every specimen out, but do not completely preclude the need for laboratory testing.

Benzodiazepine: Important Information About the Often-Abused Depressant

Naloxone: Understanding Its Role In Overdose Intervention

Naloxone: Understanding Its Role In Overdose Intervention


Naloxone, probably most-commonly referred to by the popular brand name NARCAN®, is a medication used to reverse the effects of opioids. It is most often administered to someone experiencing overdose, or other severe side-effects of opioid use, such as respiratory depression.


Although we hear a lot on the news these days about naloxone, it is certainly not new. It was patented in 1961 and approved for opioid use disorder in 1971. Of course, as the Fentanyl epidemic causes huge increases in opioid overdoses, naloxone has become a more-commonly discussed and reported-on medication.


In the simplest terms, opioids work by interacting with the opioid receptors in the human body and brain; they essentially attach to these receptors, and most opioids are considered agonists of these receptors. Conversely, naloxone is an opioid receptor antagonist, basically blocking the opioids from interacting with these receptors. Taking it a step further, naloxone is a competitive antagonist in that in addition to blocking the opioid receptors, it will take over the binding sites from the opioids that are already bound there. Of course, this is an oversimplification of the process, but it gives you an idea of the basic premise of naloxone’s functionality.


While there is some early indication that naloxone may also reverse a clonidine overdose, it is still being investigated. This is counter-intuitive, as clonidine is not an opioid, but we’ll know more as the research is developed. If this turns out to not be the case, then it would solidify the fact that naloxone can only reverse opioid overdoses. This is important to note as we see so many non-opioid adulterants and impurities in the illicit opioid supply; Xylazine is an excellent example of this. Since some 30% of Fentanyl overdoses are found to also include Xylazine, it is important to note that the NARCAN alone might not be enough to bring someone around if they are overdosing. Also, naloxone will last 30-90 minutes, while some opioids last longer; this means it is possible for the individual to experience additional overdose symptoms after the naloxone has worn off. So, while it is important to keep naloxone readily available, especially if you have an opioid user in your life, it should not be considered a 100% replacement for immediate medical attention.


Naloxone can be administered via injection; either IM (intramuscular), subcutaneous (below the skin), or IV (intravenous), but the more popular format currently is intranasal – basically as simple to use as regular nasal spray.


Most states allow pharmacists to offer Naloxone over the counter, some states require a physician’s prescription: unfortunately, there is no Federal Standing Order on naloxone, so it is left up to states how they want to address availability. And excellent resource of information regarding each state’s rules and availability can be found via this link:

Xylazine: An Emerging Threat and What You Need to Know

Fine Print to Clarity: Critical Information You Need to Know from Product Inserts