Do Urine Drug Tests Reveal Substance Misuse Among Patients Prescribed Opioids for Chronic Pain?

BACKGROUND: Urine drug testing (UDT) is a recommended risk mitigation strategy for patients prescribed opioids for chronic pain, but evidence that UDT supports identification of substance misuse is limited. OBJECTIVE: Identify the prevalence of UDT results that may identify substance misuse, including diversion, among patients prescribed opioids for chronic pain. DESIGN: Retrospective cohort study. SUBJECTS: Patients (n=638) receiving opioids for chronic pain who had one or more UDTs, examining up to eight substances per sample, during a one 1-year period. MAIN MEASURES: Experts adjudicated the clinical concern that UDT results suggest substance misuse or diversion as not concerning, uncertain, or concerning. KEY RESULTS: Of 638 patients, 48% were female and 49% were over age 55 years. Patients had a median of three UDTs during the intervention year. We identified 37% of patients (235/638) with ≥1 concerning UDT and a further 35% (222/638) having ≥1 uncertain UDT. We found concerning UDTs due to non-detection of a prescribed substance in 24% (156/638) of patients and detection of a non-prescribed substance in 23% (147/638). Compared to patients over 65 years, those aged 18-34 years were more likely to have concerning UDT results with an adjusted odds ratio (AOR) of 4.8 (95% confidence interval [CI] 1.9-12.5). Patients with mental health diagnoses (AOR 1.6 [95% CI 1.1-2.3]) and substance use diagnoses (AOR 2.3 [95% CI 1.5-3.7]) were more likely to have a concerning UDT result. CONCLUSIONS: Expert adjudication of UDT results identified clinical concern for substance misuse in 37% of patients receiving opioids for chronic pain. Further research is needed to determine if UDTs impact clinical practice or patient-related outcomes.

Intake assessment of problematic use of medications in a chronic noncancer pain clinic.

BACKGROUND: The present article outlines the process of instituting an assessment of risk of problematic use of medications with new patients in an ambulatory chronic noncancer pain (CNCP) clinic. It is hoped that the authors' experience through this iterative process will fill the gap in the literature by setting an example of an application of the 'universal precautions' approach to chronic pain management. OBJECTIVES: To assess the feasibility and utility of the addition of a new risk assessment process and to provide a snapshot of the risk of problematic use of medications in new patients presenting to a tertiary ambulatory clinic treating CNCP. METHODS: Charts for the first three months following the institution of an intake assessment for risk of problematic medication use were reviewed. Health care providers at the Wasser Pain Management Centre (Toronto, Ontario) were interviewed to discuss the preliminary findings and provide feedback about barriers to completing the intake assessments, as well as to identify the items that were clinically relevant and useful to their practice. RESULTS: Data were analyzed and examined for completeness. While some measures were considered to be particularly helpful, other items were regarded as repetitive, problematic or time consuming. Feedback was then incorporated into revisions of the risk assessment tool. DISCUSSION: Overall, it is feasible and useful to assess risk for problematic use of medications in new patients presenting to CNCP clinics. CONCLUSION: To facilitate the practice of assessment, the risk assessment tool at intake must be concise, clinically relevant and feasible given practitioner time constraints.

Experience of methadone therapy in 100 consecutive chronic pain patients in a multidisciplinary pain center.

OBJECTIVE: The objective of the study was to describe the experience of methadone use in 100 consecutive chronic pain patients managed in a single multidisciplinary center. DESIGN: A chart review of chronic pain patients on methadone therapy initiated at the Wasser Pain Management Center from January 2001 to June 2004. SETTING, PATIENTS, AND INTERVENTION: Outpatients receiving methadone for chronic pain management in a tertiary multidisciplinary pain center. OUTCOME MEASURE: Effects on pain relief and function, conversion ratio from other opioids, side effects, and disposition were reviewed. RESULTS: Charts of 100 methadone patients (age 45 +/- 11 years old; M/F: 3/7; duration of pain 129 +/- 110 months) managed by five physicians and one nurse were reviewed. The main reason for the initiation of methadone therapy was opioid rotation (72%). The average oral morphine equivalent dose was 77 mg/day before methadone therapy, and the methadone dose after initial stabilization was 42 mg with no consistent conversion ratio observed. The mean duration of methadone therapy was 11 months. Most of the patients (91%) were taking concomitant adjuvant analgesics or psychotropic agents, mostly antidepressants and anticonvulsants. The average Numeric Verbal Rating Score before and after methadone treatment was 7.2 +/- 1.7 and 5.2 +/- 2.5 (P < 0.0001). Thirty-five patients discontinued their methadone treatment mainly because of side effects, ineffectiveness, or both. CONCLUSION: From our experience, methadone is an effective alternative to conventional opioids for chronic pain management when used by experienced clinicians in a setting that allows for close monitoring and careful dose initiation and adjustment.