The role of the laboratory in pain management combines aspects of clinical and workplace toxicology (detection of drugs in urine) and therapeutic drug monitoring (measuring drug concentrations in atypical patients, explaining unusual results, and so forth). Recommendations contained in guidelines from the American Pain Society, the American Academy of Pain Medicine, and the American Society of Interventional Pain Physicians include the use of urine drug testing to monitor patients to both confirm compliance and detect the use of illicit or unprescribed drugs (1)(2). The laboratory scientist can play a key role in the development and choice of drug panels. Considerations include the medication taken (opioids/opiates), potentially abused unprescribed medications (methadone, oxycodone, fentanyl, benzodiazepines, barbiturates), illicit drugs (amphetamines, cannabinoids, cocaine, phencyclidine), masking agents, available methodologies (immunoassay screening, chromatographic confirmation), and technical considerations (analytical sensitivity and specificity, interferences, cutoff concentrations). To address these issues, laboratories may offer several different panels for pain-management drugs.
Interpretation of drug-testing results is another key role of the laboratory scientist in pain management. Interpretation often requires knowledge of drug metabolism, as illustrated in the case presented by Reisfield et al., in which they demonstrated the apparent metabolic conversion of morphine to hydromorphone, a minor metabolite. An example of the type of critical analytical thinking that the laboratory scientist can contribute to pain management in this case is the elimination of 2 potential alternative sources of hydromorphone: contamination of the ingested morphine and generation during the extraction/detection processes. Knowledge of pharmacokinetics, pharmacodynamics, pharmacogenetics, and the analytical parameters of laboratory-testing methods are all important tools that are used when interpreting results.
Author Contributions: All authors confirmed they have contributed to the intellectual content of this paper and have met the following 3 requirements: (a) significant contributions to the conception and design, acquisition of data, or analysis and interpretation of data; (b) drafting or revising the article for intellectual content; and (c) final approval of the published article.
Authors’ Disclosures of Potential Conflicts of Interest: Upon manuscript submission, all authors completed the Disclosures of Potential Conflict of Interest form. Potential conflicts of interest:
Employment or Leadership: None declared.
Consultant or Advisory Role: None declared.
Stock Ownership: None declared.
Honoraria: None declared.
Research Funding: None declared.
Expert Testimony: L.A. Broussard, Southern Nuclear, Birmingham, AL.
Role of Sponsor: The funding organizations played no role in the design of study, choice of enrolled patients, review and interpretation of data, or preparation or approval of manuscript.
- © 2009 The American Association for Clinical Chemistry