Urine Drug Testing and Monitoring in Pain Management
In a previous Guest Editorial (Practical Pain Management, March, 2006), a laboratory perspective on “Clinical Drug Testing for Pain Medicine” was presented. This report will focus on guidelines regarding the utilization and rationale for urine drug testing and monitoring in the management and treatment of pain.
The integration of laboratory diagnostics into routine clinical practice is essential and can be procedurally challenging. Both newly developed, and what are considered routine diagnostic procedures, are continually being improved. It is critical that the laboratory industry continue to educate and distribute pertinent information to clinicians in an intelligent and expeditious manner. This will efficiently facilitate the incorporation of these procedures and minimize laboratory and interpretive errors.
The clinical practice of pain medicine is growing at a rapid pace. Lagging behind are both standards and procedures for objective diagnostics including biomarkers, molecular diagnostics, drug testing, or more accurately, clinical pharmacological monitoring. This is in part due to the slow pace of basic research and an incomplete understanding of the biochemistry, physiology, and genetics of pain. The use of pharmacological agents should be supported by scientifically sound, precise, accurate, and objective laboratory diagnostics.
Inherent in the evolution of clinical laboratory procedures is the need to standardize a diagnostic language and vocabulary as it pertains to pain medicine. Procedures need to be implemented to optimally share information among ancillary support systems, physicians, payers, governmental agencies, pharmacies, workers’ compensation bureaus, laboratory staff, and clinical support staff, and especially to the patients and their families.
The laboratory discipline of Clinical Pharmacology/Toxicology is complex and technically challenging. Pharmacotherapy is also complex, even when there is a thorough understanding of the disease and the prescribed medication(s). Drug therapy is, and will continue to be, difficult until we have a basic molecular understanding of endogenous pain mediating systems, and ultimately, new drug targets. This understanding will facilitate the discovery and development of new drugs and laboratory tests.
The pharmacological management of the pain patient is multidisciplinary and includes both clinical aspects of the pain itself and other possible issues including addiction, pseudoaddiction, tolerance, undertreatment of pain, drug diversion, misuse and abuse, and drug-drug interactions. These issues can range from clinical to forensic to legal. Laboratories are being tasked to develop and perform procedures that will satisfy all of these criteria. This is a new phenomenon for the clinical diagnostic laboratory, as historically these issues have been divided into forensic/workplace (non-clinical) testing and therapeutic (clinical) drug monitoring. The underlying science and performance of these two divergent tasks can be very different.
Drug testing is now becoming an accepted and important tool in the clinical world.1,2 Due to potential forensic/punitive issues involving schedule II medications, drug testing pain patients can create a level of discomfort for both physician and patient. This situation can be alleviated and/or eliminated by open dialogue and accurate documentation regarding why drug testing is an essential part of the treatment process.
It is also essential to protect both the pain practice and the laboratory by providing diagnostic and documentation procedures that support pharmacotherapeutic protocols and treatment plans. This documentation must be conveyed to the patient and should assist in objectifying aspects of drug treatment and enhance physician/patient trust.
The following are key clinical reasons for incorporating drug testing into routine pain practice.