What is the recommended pain management regimen for a post-operative patient, considering their risk of opioid addiction and history of substance abuse?

Postoperative Pain Management in Patients with Substance Abuse History

For post-operative patients with a history of substance abuse, implement aggressive multimodal non-opioid analgesia as the foundation—scheduled acetaminophen 1000 mg every 6-8 hours plus NSAIDs (if no contraindications), combined with regional anesthesia techniques when feasible—and reserve short-acting immediate-release opioids strictly for breakthrough pain unresponsive to non-opioid therapy, prescribing no more than 5-7 days supply with explicit time-limited instructions. 1, 2

Core Multimodal Non-Opioid Foundation

The cornerstone of pain management in former addicts must be aggressive multimodal non-opioid analgesia to minimize opioid exposure and relapse risk. 1

First-Line Scheduled Medications

• Acetaminophen 1000 mg orally every 6-8 hours should be the primary analgesic, as it is the safest non-opioid option with proven efficacy in reducing opioid consumption, shortening hospital length of stay, and improving postoperative outcomes. 2, 1

• Add NSAIDs or COX-2 inhibitors for synergistic pain relief if no contraindications exist (avoid in renal dysfunction, cardiovascular disease, or colorectal surgery with anastomoses due to increased dehiscence risk). 2, 1, 3

• The combination of acetaminophen and NSAIDs provides additive analgesic effects and significantly reduces opioid requirements. 2

Regional Anesthesia Techniques

• Utilize nerve blocks, interfascial plane blocks, or local anesthetic wound infiltration whenever anatomically appropriate, as these provide superior analgesia while completely avoiding systemic opioids. 1, 4

• Regional techniques should be prioritized in the surgical plan for high-risk addiction patients. 4

Adjunctive Medications for Enhanced Analgesia

• Consider gabapentinoids (gabapentin or pregabalin) as components of multimodal analgesia, as they decrease neurotransmitter release and provide nociceptive blocking activity that reduces opioid requirements. 2

• Intraoperative dexmedetomidine infusion (0.07 μg/kg/h) can reduce opioid requirements through sympatholytic effects and improve outcomes including reduced delirium. 2, 1

• Low-dose ketamine infusion intraoperatively (bolus <0.35 mg/kg, infusion 0.5-1 mg/kg/h) provides analgesia with minimal respiratory depression in severe pain scenarios. 2, 1

Opioid Use: When and How

Opioids should only be used when multimodal non-opioid therapy fails to control pain that interferes with function, and then only as short-acting full agonists in limited quantities. 1, 2

Prescribing Guidelines for Breakthrough Pain

• Prescribe immediate-release oxycodone 5 mg tablets (or liquid oral morphine 10 mg/5 mL) for breakthrough pain only, limiting the prescription to 15-20 tablets maximum (5-7 days supply, never more than 7 days). 2, 1

• Avoid modified-release opioid preparations (including transdermal patches) without specialist consultation, as they have been associated with harm and make dose titration difficult. 2

• Dose should be age-related rather than weight-based and must consider renal function, with alternative opioids preferred in elderly patients over 70 years or those with renal failure. 2

• Avoid initial continuous infusion or PCA in opioid-naïve patients; start with bolus dosing only if needed. 2

Monitoring Requirements

• Record sedation scores in addition to respiratory rate to detect patients at risk of opioid-induced ventilatory impairment. 2

• Monitor regularly for adverse events, particularly in the first 24-72 hours after initiating opioid therapy. 5

Discharge Planning and Safety Measures

Patient Education (Critical to Prevent Diversion)

• Provide explicit written and verbal instructions to take acetaminophen and NSAIDs on schedule, use opioids only for breakthrough pain, and understand the time-limited nature of opioid therapy. 1, 2

• Warn patients about dangers of driving or operating machinery while taking opioid medications and provide a patient information leaflet. 2

• Instruct patients to dispose of unused opioids by returning to pharmacy or flushing down toilet, as only 12% dispose appropriately, creating significant community diversion risk. 1

Prescription Documentation

• The hospital discharge letter must explicitly state the recommended opioid dose, amount supplied, and planned duration of use, with the opioid treatment plan agreed upon with the patient. 2

• Provide discharge letter in a timely way to all healthcare professionals including community pharmacists to prevent acute prescriptions inadvertently becoming repeat prescriptions. 2

Reverse Analgesic Ladder

• When analgesic requirements decrease, wean opioids first, then stop NSAIDs, and finally stop acetaminophen. 2

• Encourage patients to keep a record of analgesics taken, as research shows this results in better pain control. 2

Special Considerations for Patients on Medication-Assisted Treatment (MAT)

For Patients on Methadone or Buprenorphine

• Continue baseline methadone or buprenorphine unchanged perioperatively to prevent withdrawal and relapse in patients on medication-assisted treatment for opioid use disorder. 1, 6

• For patients on buprenorphine ≤12 mg sublingual daily, continue the dose unchanged perioperatively. 6

• Divide buprenorphine dosing to every 6-8 hours rather than once daily for better analgesic coverage in the postoperative period. 1, 6

• Implement aggressive multimodal analgesia as these patients may require higher doses of full mu-opioid agonists (expect 2-4 times typical requirements) for breakthrough pain due to competitive receptor blockade. 6

• Coordinate with the patient's buprenorphine provider for perioperative planning and postoperative follow-up. 6

Common Pitfalls and How to Avoid Them

• Do not prescribe combination products (oxycodone/acetaminophen) as they prevent independent dose adjustment; prescribe opioid and non-opioid analgesics separately. 2

• Do not forget to account for acetaminophen in combination products to avoid exceeding 4000 mg daily total dose and risk hepatotoxicity. 2

• Do not abruptly discontinue buprenorphine in patients with opioid use disorder, as this precipitates withdrawal and increases relapse risk. 6

• Do not use NSAIDs in colorectal surgery with anastomoses due to proven increased risk of anastomotic leak and wound healing inhibition. 2, 3

• Do not delay adequate pain control based on addiction history alone—untreated severe pain increases stress response and worsens outcomes. 2