Perspectives on Clinical UDT
In pain care settings, patients are typically expected both to test positive for prescribed medications that otherwise might be considered substances of abuse, such as opioids or benzodiazepines, and to test negative for non-prescribed controlled medications and illicit drugs. Medication monitoring and drug detection in pain treatment patients often begins with in-office urine screens to provide general information on the drugs or drug classes that are present.
Point-of-care (POC) screening devices contain panels for a limited number of drugs or drug classes. Thus, a given device may not be designed to detect some of the most commonly prescribed medications, including synthetic (eg, fentanyl) and some semisynthetic (eg, oxycodone) opioids, some benzodiazepines (eg, clonazepam), muscle relaxants (eg, carisoprodol), and other pain-care-relevant and illicit drugs [SAMHSA 2012].
Furthermore, preliminary POC screening test cutoff concentrations may not be low enough in some instances to detect therapeutic doses of medications or small amounts of illicit substances (eg, cannabinoids, methamphetamine) [SAMHSA 2012]. The cutoff is an administratively determined concentration of a drug or metabolite, at or above which the result is reported as positive (drug present), and below which the result is reported as negative (drug absent) [Leavitt 2005].
So, basic in-office screening tests can, within minutes, provide a preliminary indication of whether or not a patient is likely to be taking the drug or class of drug of interest [Peppin et al. 2012]. However, this alone is often insufficient to address the questions that must be asked and answered in patients being treated for pain [SAMHSA 2012; Webster and Dove 2007].
Therefore, a portion of the patient’s urine specimen is sent to a laboratory for highly accurate quantitation and identification of specific drugs and/or their metabolites, using lower cutoff levels and an extended test menu. If a broad enough approach is used, it will inform the clinician of a wide variety of pharmacologic substances in the patient’s urine — whether prescribed, nonprescribed, or illicit — within a turnaround of a few days or less (depending on laboratory capabilities), allowing for timely patient care decisions [Peppin et al. 2012].
It is important to emphasize that, while there has been a great deal of concern about opioid analgesic prescribing, these are not the only medications used in pain management and worthy of monitoring. It can be of vital importance to know, as part of the treatment plan and for safety reasons, whether or not patients are taking their antidepressants, anticonvulsants, anxiolytics, muscle relaxants, or other agents as prescribed. UDT, using advanced laboratory-based assays, can help to provide the answers.