Expires: July 13, 2023
Paul Jannetto, Ph.D.
Associate Professor of Laboratory Medicine and Pathology
Director of Clinical and Forensic Toxicology, Clinical Mass Spectrometry Lab, and Metals Lab
Mayo Clinic, Rochester, Minnesota
Contact us: email@example.com.
Hi, I’m Dr. Matt Binnicker. Balancing the need for pain medication against the use of addictive and potentially deadly opioid pain relievers is something the medical community struggles with. In this month’s “Hot Topic,” Dr. Paul Jannetto discusses high-resolution targeted opioid screening tests from Mayo Clinic Laboratories, which offer sensitivity and specificity for use in the monitoring and management of patients who are prescribed opioid pain-reliving medication. I hope you enjoy this Hot Topic, and I want to personally thank you for allowing Mayo Clinic the opportunity to be a partner in your patient’s health care.
I have nothing to disclose.
The objectives of my talk are to:
The United States is currently experiencing an epidemic of prescription opioid misuse and overdose. Increased prescribing and sales of opioids—a quadrupling since 1999—helped create and fuel this epidemic. In fact, enough opioid pain relievers were prescribed to medicate every adult American around the clock, giving them 1 pill every 4 hours for a month. Yet despite the use of potent narcotics to manage pain, 40% of patients still report being inadequately treated for pain. Medical examiner reports also continue to show an increase in opioid-related fatalities. In the end, chronic pain is a major contributor to health care costs, which are estimated at over $635 billion dollars per year in medical treatment and lost productivity.
Why do physicians use UDT to monitor pain management patients? Currently, there are numerous clinical practice guidelines published that support the use of laboratory tests to monitor compliance in pain patients.
For example, the American Society of Interventional Pain Physicians have a guideline that states that UDT must be implemented from initiation along with subsequent adherence monitoring to decrease prescription drug abuse or illicit drug use when patients are in chronic pain management therapy. The purpose of UDT is to verify adherence to prescribed medications, identify undisclosed drugs, and discourage drug misuse, abuse, and diversion.
The actual use of UDT as part of adherence monitoring has been associated with a 49% reduction in opioid abuse according to a publication by Manchikanti.
In March 2016, the CDC also issued new recommendations for prescribing opioid medications for chronic pain as part of the urgent response to the epidemic of overdose deaths. The new guideline aims to improve the safety of prescribing and curtail the harms associated with opioids, including opioid use disorder and overdose.
In regards to UDT, the CDC specifically recommended that when prescribing opioids for chronic pain, clinicians should use UDT before starting opioid therapy and consider UDT at least annually to assess for prescribed medications, as well as other controlled prescription drugs and illicit drugs.
There are also financial reasons to use UDT to monitor pain management patients. For example, it has been shown that nonadherence to opioid therapy leads to increased health care utilization and cost. Furthermore, the early monitoring of opioid adherence using UDT may provide substantial cost savings associated with health care issues incurred in non-adherent chronic pain patients.
Finally, there is also the fear of regulatory scrutiny. There are both state and federal regulations that cause physicians to use UDT to monitor pain management patients. Currently, most states have specific regulations, guidelines, or policy statements for prescribing opioid analgesics for pain management. Some states actually discourage or prohibit physicians from prescribing opioids to patients whom they know or should know are using controlled substances for nontherapeutic purposes. On the other hand, the federal regulations do not prohibit the use of opioids to treat pain if a patient is abusing controlled substances.
So what types of urine opiate tests are being used by physicians to determine compliance to opioid pain management therapy? Routinely, physicians may use qualitative screening assays, or definitive assays. Screening assays typically identify the drug and/or drug metabolite with variable specificity and often only by drug class. These are commonly immunoassay-based, offer quick turnaround time on automated platforms, and have higher cutoffs. Alternatively, physicians may use definitive tests where they can identify and/or quantify an individual drug or drug metabolite with high specificity and better sensitivity. These tests are commonly performed using mass spectrometry-based methods.
However, physicians are primarily using screening assays with or without confirmatory assays to verify adherence in pain management patients. There are two types of screening assays. Traditional screening assays use antibodies directed against a drug or drug metabolite. These immunoassays may be in a point-of-care format so the test can be done right in the physician’s office or clinic, or they can be commercially based immunoassays run in CLIA-certified laboratories. Alternatively, new targeted laboratory-developed screening assays using mass spectrometry have also started to emerge as a screening tool, like the new opioid assay I am talking to you about today. Each of these types of assays has advantages and disadvantages.
Point-of-care tests have the advantage of having the fastest turnaround time, so the physicians can get an immediate result, which is good for patients who have a high risk for abuse or reside far from care. Laboratory-based immunoassays typically have a larger test menu and are more economical. However, all immunoassays suffer from higher cutoffs and limited sensitivity and specificity. On the other hand, targeted screens have better sensitivity and specificity, but aren’t widely available at all local laboratories.
Cross-reactivity with immunoassays is a big issue that needs to be considered when interpreting screening test results. For example, in the urine opiate immunoassay the antibody used in most manufacturer kits is directed against morphine. It has limited-to-no cross-reactivity with all of the other opioids used in pain management. As you can see, a standard urine opiate immunoassay has a pretty good cross-reactivity with codeine and the metabolite of heroin (6-acetyl morphine). However, a patient’s urine sample would need to have a much higher concentration (higher than the 300 ng/mL cutoff) of oxycodone and/or oxymorphone to get a “positive” result using this assay. In addition, you will notice that other opioids like methadone, tramadol, fentanyl, or tapentadol are absent from this list since they do not cross-react at all with this assay, and you will get a “negative” result even if these drugs are present in the patient’s urine.
The following slide demonstrates how a patient may test “negative” on a urine immunoassay, which has a higher cutoff and varying degrees of cross-reactivity to all opioids compared to a liquid chromatography-tandem mass spectrometry-based method (LC-MS/MS). In this study, Mikel and colleagues took the urine of pain management patients and tested it both using an immunoassay and an LC-MS/MS assay. The urine opiate immunoassay had a cutoff of 300 ng/mL, while the LC-MS/MS assay had a cutoff or detection limit of 50 ng/mL.
If you look at the hydromorphone results, you can see that approximately 69% of patients who were prescribed and taking hydromorphone tested “positive” or had detectable concentrations on the LC-MS/MS method, but tested “negative” on the immunoassay due to the higher cutoff and poor cross-reactivity of the immunoassay antibody with hydromorphone.
The features and benefits of the new high-resolution targeted opioid screen include:
Here is the complete list of the 33 opioids and metabolites along with the cutoffs or concentration required to give a positive or “present” result. This one test will allow clinicians to not have to remember which opioid does or does not cross-react with the urine opiate immunoassay, or have to order multiple different immunoassays and/or confirmatory tests to look for all of the different opioids like buprenorphine, fentanyl, methadone, tramadol, and tapentadol.
The high-resolution targeted opioid screen also will improve test utilization without compromising turnaround times. It will reduce the need for confirmatory testing that is required with traditional immunoassays since they don’t specifically identify which opioid is present. Because it detects both parent and metabolite of an opioid, we can identify spiked samples where patients crush up pills and then add them into the urine instead of ingesting them. Lastly, this new test comes with an enhanced PDF report that has interpretative comments to aid the clinician with the interpretation of the test results.
Here is an example of an enhanced report. If the client has entered the prescribed opioids when ordering the test, the medications will be displayed at the top. The next section is the interpretation section where a comment is given providing guidance regarding the test results. All positive results are pulled into the top section of the report so the clinician can immediately see what was present or detected. It also provides some additional information regarding brand names or if something is a metabolite or possibly impurity of another drug. The last section shows all the analytes tested for that were negative or not detected.
Now let’s look at one clinical case study comparing a traditional approach using immunoassay screens with reflex to confirmatory testing compared to the new high-resolution targeted opioid screen.
In this case, we have a 38-year-old male with chronic back pain who is taking hydrocodone (10 mg twice a day) along with a rescue pain medication (tramadol), which is taken as needed for breakthrough pain. The ordering physician sees the patient is improving based on the visual analog scale (originally 6/10, and now 3/10), but orders a UDT (pain management panel) that uses a variety of immunoassays to screen for drugs of abuse and opiates and reflexes to confirmatory testing if positive.
The purpose of the urine drug test is to check for adherence to the prescribed medications (hydrocodone and tramadol). The screening results come back “presumptive positive” for opiates, but we don’t know which opiate may or may not be present. As a result, the opiate confirmation test is automatically performed and shows both hydrocodone (2,153 ng/mL) and hydromorphone (1,780 ng/mL).
As a result, how should the physician interpret these results? The patient is prescribed hydrocodone and tramadol and admits taking both of these medications daily (the last dose in the morning prior to collection of the urine sample). However, the test only shows hydrocodone and hydromorphone.
As a result, the physician wants to know where the hydromorphone came from since it can be a separate prescribable drug (brand name = Dilaudid).
As you can see from this simplified figure showing the endogenous metabolism of some opioids, hydrocodone is metabolized to hydromorphone by the cytochrome P450 system (specifically CYP2D6).
Based on the concentrations and the metabolic ratio of hydrocodone to hydromorphone, these results are most likely consistent with hydromorphone being a metabolite of hydrocodone.
As a result, the patient has taken the hydrocodone at least in the past three days.
However, the physician still wants to know where is the tramadol? In this case, the physician has to order an additional confirmatory test for tramadol and its metabolite, which ordered does come back positive or detectable. Unfortunately, this resulted in additional testing, expense, and a delay in the final results.
Now let's look at this same case study, but use the new high-resolution targeted opioid screening test. Alternatively, this new test will also be incorporated into a new controlled substance monitoring panel if a physician wants to look for other drugs of abuse or medications.
In this case, the physician just ordered the targeted opioid screen on the urine sample and got the following results back:
Based on the pattern of analytes, the interpretation stated that the test detected the presence of hydrocodone and several of its metabolites (hydromorphone, dihydrocodeine, and norhydrocodone). Suspect use of hydrocodone within the past three days.
Also, the test detected the presence of tramadol and its metabolite (o-desmethyltramadol). Suspect use of tramadol within the past three days.
These results are consistent with the patient’s prescribed medications and no additional tests need to be ordered.
In summary, objective measures like laboratory tests are needed to identify and evaluate adherence or misuse or abuse of controlled substances.
The new high-resolution targeted opioid assay:
In the end, all UDT results must be interpreted in the context of the test, drugs prescribed, specimen type, time since last dose and sample collection, specimen validity test results, and the patient. Unexpected or unexplained results should be discussed with the patient and laboratory, and additional testing performed if needed.
Thank you for your attention. I hope you found this presentation useful. If you have any questions, please contact Mayo Clinic Laboratories.