Abstract
BACKGROUND: Managing acute pain in patients with opioid use disorder (OUD) on medication (methadone, buprenorphine, or naltrexone) can be complicated by patients' higher baseline pain sensitivity and need for higher opioid doses to achieve pain relief. This review aims to evaluate the benefits and harms of acute pain management strategies for patients taking OUD medications and whether strategies vary by OUD medication type or cause of acute pain. METHODS: We systematically searched multiple bibliographic sources until April 2020. One reviewer used prespecified criteria to assess articles for inclusion, extract data, rate study quality, and grade our confidence in the body of evidence, all with second reviewer checking. RESULTS: We identified 12 observational studies-3 with control groups and 9 without. Two of the studies with control groups suggest that continuing buprenorphine and methadone in OUD patients after surgery may reduce the need for additional opioids and that ineffective pain management in patients taking methadone can result in disengagement in care. A third controlled study found that patients taking OUD medications may need higher doses of additional opioids for pain control, but provided insufficient detail to apply results to clinic practice. The only case study examining naltrexone reported that postoperative pain was managed using tramadol. We have low confidence in these findings as no studies directly addressed our question by comparing pain management strategies and few provided adequate descriptions of the dosage, timing, or rationale for clinical decisions. DISCUSSION: We lack rigorous evidence on acute pain management in patients taking medication for OUD; however, evidence supports the practice of continuing methadone or buprenorphine for most patients during acute pain episodes. Well-described, prospective studies of adjuvant pain management strategies when OUD medications are continued would add to the existing literature base. Studies on nonopioid treatments are also needed for patients taking naltrexone. PROTOCOL REGISTRATION: PROSPERO; CRD42019132924.