Pain Management for Patients with Substance Use Disorder

Initial Assessment and Stabilization

The American College of Physicians recommends verifying the patient's current maintenance therapy dose with their prescribing provider or program before initiating any pain management plan, as patients on methadone or buprenorphine have developed significant opioid tolerance and cross-tolerance to other opioids 1
Undertreating pain can lead to decreased responsiveness to subsequent opioid analgesics, and the presence of addiction worsens pain perception through withdrawal syndromes, intoxication, sympathetic arousal, and affective changes 3
Reassuring patients explicitly that their addiction treatment will continue uninterrupted and that their pain will be aggressively treated decreases anxiety and improves cooperation with the treatment plan 1, 2

The National Comprehensive Cancer Network recommends starting with acetaminophen 650 mg every 4-6 hours (maximum 4-6 grams daily) and/or NSAIDs as the foundation of a multimodal analgesic strategy, and continuing these agents even after opioid initiation if they provide additional analgesia and are not contraindicated 4, 5, 6, 7
For patients on methadone, continuing the patient's usual daily methadone dose for maintenance of their opioid dependence, and adding short-acting opioids (morphine, hydromorphone, or oxycodone) for pain control, using scheduled dosing at fixed intervals and higher doses and more frequent intervals than for opioid-naïve patients due to cross-tolerance 1, 2, 3
For patients on buprenorphine, continuing buprenorphine maintenance therapy and adding short-acting full opioid agonists, and collaborating with palliative care, pain, and/or substance use disorder specialists to determine the optimal approach 3, 7

The American Society of Addiction Medicine recommends never using mixed agonist-antagonist opioids (pentazocine, nalbuphine, butorphanol) as they can precipitate acute withdrawal syndrome, and avoiding tramadol and codeine in this population due to limitations in dose titration and potential for neurotoxicity and significant drug interactions 1, 2, 7

The American Academy of Pain Medicine recommends monitoring frequently for level of consciousness and respiratory rate, signs of opioid toxicity or overdose, and having naloxone immediately available 2, 7
Establishing clear treatment agreements regarding number of pills dispensed, frequency of use, expected duration of treatment, and single provider/pharmacy when appropriate 1, 4, 5, 6

For patients with renal impairment, rotating to methadone (excreted fecally) if not contraindicated, carefully titrating fentanyl, oxycodone, or hydromorphone, and avoiding morphine, meperidine, codeine, and tramadol 7