Hey Doc, Glen`s drug test results are back. And they indicate the presence of opioid-consistent with ADHD medications.
Does that indicate that the patient is adhering to their prescriptions?
Well, not so fast.
For one, detecting ADHD medications in Glen`s urine does not eliminate the possibility that he (Glen) could have “pill shaved” to pass the test. All while diverting the presence of other medications or drugs.
By definition, pill shaving is the practice of crushing or scraping part of a pill and dissolving it in a urine sample.
It`s commonly done to:
- Test positive for a prescribed medication the patient has not taken. Mainly because they refuse to take it, are saving it for later, traded it for another drug, or diverted it for sale.
- Adulterate someone else`s urine to pass it for testing as their own. This is common when the patient or an individual`s urine would show the presence of non-prescribed or illicit drugs.
So what can you do to rule out pill shaving?
See, many patients may take their medications as prescribed. However, the open access to medications, such as opioids, cocaine, cannabinoids, phencyclidine, and amphetamines; presents a chance to trade or sell medications to individuals not permitted to receive them.
The said drug diversion is a key cause of misuse of prescription drugs. A misuse that poses a risk to patients who fail to take the medication and individuals receiving and taking the medication – without a physician`s authorization!
Given the risks, healthcare providers need to go above and beyond when drug testing. A simple screen or presumptive test is not enough to ensure that patients are taking their medications as prescribed.
Because a positive result for the prescribed medication does not necessarily indicate prescription adherence.
A presumptive test can only indicate whether the urine sample contains the afore-listed drug classes. It does not distinguish whether the patient ingested the drug, is using Quick Fix Plus 6.2 Synthetic Urine or “shaved” a part of the drug into their urine to fool the test.
The solution?
Definitive testing
Realizing that a patient who has traded or sold their prescription drugs can still retain some for “pill shaving” purposes, it`s vital to confirm the realized results using the definitive methodology.
More so, when you have patients who are chronic opioids, benzodiazepines, or stimulants… or who are on controlled substances.
A properly done urine drug screening involves two steps: i. the initial screening test and ii. A confirmation testing to rule out false positives and false negatives.
The initials test is often an immunoassay designed to test for the 5 major drug classes: cocaine, cannabinoids, opioids, phencyclidine, and amphetamines. These five classes are the most targeted by workplaces.
The tests that yield positive results in conjunction with those indicating unexpected negative results are then sent for confirmatory testing.
To avoid second orders, consider ordering the initial screening to automatically reflex to confirmation when there are cases of positives or false negatives.
Note, a typical screening can only detect morphine, codeine, and such other non-synthetic opioids.
A routine immunoassay detects the presence of illicit substances like cocaine or cannabis. However, they rarely recognize synthetic urine or semi-synthetic opioids like buprenorphine, oxycodone, oxymorphone, or fentanyl. It does not distinguish between opioids either.
Also, most benzodiazepine immunoassays can reliably detect oxazepam, temazepam, and nordiazepam. But cannot recognize lorazepam, clonazepam, or alprazolam. Hence the need for a confirmatory test as well as orders for specific modifications if need be. More so in case of positives or false negatives.
Confirmation testing often uses liquid or gas chromatography to separate substances, and mass spectrometry to detect and identify each of the separated substances. It is highly accurate and can recognize individual metabolites and drugs.
The downside, the confirmatory testing is too expensive to be ordered for every drug. Rather, providers should direct such tastings to specific medications that the patient should be taking. Or when there is a suspected use of non-prescribed substances.
Case history
Primary caregivers cannot solely rely on urine drug testing as a measure of a patient adherence to drug prescriptions. In any case, these tests cannot detect intermittent use of non-prescribed substances.
That calls for a historical examination of the patient`s drug use; using tools such as Pain Medication Questionnaire, Opioid Risk Tool, and Addiction Behaviour checklist. Prescription monitoring profiles and a full body examination can help too.
The health provider should note:
- The last time the individual took their prescribed medication to determine the likelihood of a positive test
- A list of additional prescriptions that the patient could be using taking to check the possibility of cross-reaction.
- Whether illicit or non-prescribed drugs were taken.
Let`s take the case example of Glen.
Glen Wahliq, a 28-year-old Caucasian male, presented to your medical office 1.5 months ago as a new patient. He claimed to have severe (a 7 out of 10) back pain whose possible cause was a motorcycle accident when he was 20. He did not voice any other complaints.
Currently, he was not taking any medications for chronic pain as the prescription from his previous health provider had run out.
You did a physical exam, and it was unremarkable. Well, except for the mild limitation of the truncal rotation. The neurologic exam results were
okay.
A baseline drug test from an unobserved urine sample, done with a point-of-care test cup, indicated no sign of controlled or illicit substances.
So you went ahead and prescribed 40mg of oxycodone twice a day, and directed him to for a follow-up check-up and urine drug test in 1.5 months.
At the revisit, Glen reports that his pain had dropped from 7 to 2 out of 10.
His urine sample is again collected – unobserved.
You order an immunoassay screen for oxycodone and opiates, coupled with an automatic reflex for confirmatory testing.
Three days later, Glen results come back:
You order a presumptive screen for opiates and oxycodone, with an automatic reflex for definitive testing. Three days later, results come back:
- Immunoassay screen for oxycodone: positive
- Confirmatory test: negative for metabolites and positive for oxycodone.
Interpreting the Urine Drug Test
So, is Glen taking his prescribed medications?
Well, Glen is almost certainly not taking his prescribed medication.
The absence of oxycodone metabolites (such as noroxycodone and oxymorphone) shows that Glen had not taken the drug in the last 1-3 days. That is the detectable period.
On its end, the positive oxycodone results mean that the drug oxycodone was present in the collected urine sample. And the most likely cause would be a purposeful adulteration of the test sample through pill shaving.
Thus, use your objective judgment to have an honest conversation with Glen. Get to understand why he is not taking his medications.
Note, oxycodone – as used in the case study above – is not the only medication liable to diversion. Methamphetamine, benzodiazepines, other opioids, in line with other drugs with some street value, can be traded or sold.
Again, the urine drug test can be a lot difficult to interpret than described above. For starters, benzodiazepines and opioids contain multiple substances in which their metabolites overlap.
For instance, presence of morphine in the urine could mean that the patient had morphine, codeine, heroin, or a combination of these substances. Which makes it hard to narrow down.
Cross-reaction between commonly used medications can lead to false positives. While excessive dilution and cases of drugs that are easily broken down can lead to false negatives.
The definitive testing for both the prescribed medication and its metabolites is a sure way to detect whether or not your chronic patients are taking their prescribed drugs.
Where positive medication and metabolites mean the patient is diligently taking their medications. But a negative metabolite presence with a positive medication presence means the patient is not taking their drugs, but are too cunning to consider fooling the test.
The most common ways used to tamper samples (collected unobserved) include the addition of substances, the substitution of test samples, and dilution with water.
While many labs will check urine creatinine levels to detect any contamination and dilution, it is worth acknowledging instances where there are unintentional exposure or ingestion of substances that can lead too false results.
What Next after Finding Evidence Inconsistent with your Prescriptions?
It is hard for a health care provider to consider that their patients could be diverting their medications. Besides, no test results can identify a diversion – if present.
However, results from a drug screen –as discussed above – give you an objective conclusion you can use to begin a candid conversation with your patient – helping you understand their problems in a more in-depth manner.
For a successful conversation, it is best to present your evidence in a non-threatening manner – and explain the inferences you drew from it and why.
For such an environment eliminates judgment, accusations, suspicions, and personal bias.
Nonetheless, it is vital to consider that some patients might be honest, while others might lie their way out of it. Thus,
- If a patient still requires the drugs, conduct more frequent screening, and have them carry their pill bottle along; and account for the missing medications. Design the check-ups in a way that encourages compliance.
- Consider a dose reduction to match the actual medical requirements of the patient. And,
Discontinue the prescription if the patient does not need the medication.
