What is the recommended algorithm for pain management?

Pain Management Algorithm

The recommended pain management algorithm follows a stepwise approach based on pain intensity, with acetaminophen and NSAIDs as first-line treatments for mild to moderate pain, and opioids reserved for severe pain or when first-line treatments fail. 1

Step 1: Assessment and Classification

• Assess pain using a standardized scale (0-10 numeric rating scale):
  • Mild pain (1-3)
  • Moderate pain (4-7)
  • Severe pain (8-10)
• Determine pain type:
  • Nociceptive (somatic or visceral)
  • Neuropathic
  • Mixed
• Identify if pain is related to oncologic emergency (requires immediate intervention)
• Determine if patient is opioid-naïve or opioid-tolerant

Step 2: Initial Treatment Based on Pain Intensity

For Mild Pain (1-3/10):

• First-line: Non-opioid analgesics
  • Acetaminophen (up to 4000 mg/day)
  • NSAIDs (e.g., ibuprofen 400-600 mg every 6 hours)
  • Topical NSAIDs for localized musculoskeletal pain 2
• Cautions:
  • Limit acetaminophen in hepatic disease
  • Avoid NSAIDs in GI bleeding risk, cardiovascular disease, renal disease

For Moderate Pain (4-7/10):

• First-line: Optimize non-opioid analgesics
  • Maximum doses of acetaminophen and/or NSAIDs
  • Consider fixed-dose combination of acetaminophen/NSAID 3
• Second-line: Add weak opioid or low-dose strong opioid
  • Tramadol 50-100 mg every 4-6 hours (max 400 mg/day) 1
  • Low-dose oxycodone (5-15 mg every 4-6 hours) 4

For Severe Pain (8-10/10):

• First-line: Strong opioids with around-the-clock dosing
  • Morphine, oxycodone, or hydromorphone
  • Start with short-acting formulations for rapid titration
  • Include breakthrough pain medication (typically 10-15% of 24-hour dose) 1
• Always combine with:
  • Non-opioid analgesics (unless contraindicated)
  • Bowel regimen to prevent constipation
  • Antiemetics as needed

Step 3: Specific Approach for Neuropathic Pain

• First-line options: 1, 5
  • Gabapentin (start 100-300 mg at bedtime, target 900-3600 mg/day)
  • Pregabalin (start 75 mg twice daily, target 300-600 mg/day)
  • Duloxetine (start 30 mg daily, target 60-120 mg daily)
  • Secondary amine TCAs (nortriptyline, desipramine 10-25 mg at bedtime, target 50-150 mg)
• Second-line options:
  • Combination therapy with first-line agents
  • Topical lidocaine 5% for localized peripheral neuropathic pain
• Third-line options:
  • Tramadol or other opioids if refractory to above treatments

Step 4: Reassessment and Adjustment

• Reassess pain control and side effects frequently
• If substantial pain relief (pain ≤3/10) with tolerable side effects:
  • Continue current treatment
• If partial pain relief (pain remains ≥4/10):
  • Increase dose to maximum tolerated within recommended range
  • Add another agent with different mechanism of action
• If inadequate pain relief (<30% reduction):
  • Switch to alternative agent in same or different class

Step 5: Refractory Pain Management

• Consider referral to pain specialist or multidisciplinary pain center
• Consider advanced interventional techniques
• For cancer pain, consider:
  • Radiation therapy for bone metastases
  • Nerve blocks
  • Intrathecal therapy

Non-Pharmacological Approaches

• Evidence-based options to incorporate at any step: 1, 5
  • Cognitive behavioral therapy (strong evidence)
  • Physical and occupational therapy
  • TENS (transcutaneous electrical nerve stimulation)
  • Yoga for musculoskeletal pain
  • Hypnosis (particularly for neuropathic pain)

Important Considerations

• Set realistic expectations: aim for 30-50% pain reduction and improved function
• For chronic pain, use scheduled dosing rather than as-needed
• Monitor for adverse effects and adjust therapy accordingly
• For opioids, use lowest effective dose for shortest duration
• Screen for risk factors for opioid misuse before prescribing

This algorithm provides a structured approach to pain management that prioritizes non-opioid options first, with escalation to opioids only when necessary and with appropriate monitoring and precautions.