What is the recommended treatment for acute pain?

Treatment of Acute Pain

For acute pain, first-line treatment should be acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs), with ibuprofen 400mg every 4-6 hours being the optimal initial choice for most patients. 1, 2

Algorithmic Approach to Acute Pain Management

Step 1: Initial Assessment and First-Line Medications

• For mild to moderate acute pain:
  • Start with ibuprofen 400mg every 4-6 hours as needed 3, 4
  • OR acetaminophen 1000mg every 6 hours (maximum 4g/day) 2, 5

Step 2: Medication Selection Based on Patient Factors

• Choose acetaminophen when patient has:

  • History of GI bleeding
  • Cardiovascular disease
  • Renal impairment
  • Use lower doses (≤3g/day) in patients with advanced hepatic disease or alcohol use disorder 5

• Choose NSAIDs (ibuprofen preferred) when:

  • Inflammatory component is present
  • Patient has no contraindications
  • Use the lowest effective dose for shortest duration 3

Step 3: For Inadequate Response to First-Line Agents

• Add skeletal muscle relaxants if:

  • Muscle spasm is present, particularly with back pain 1
  • Be aware of sedation as primary side effect 1

• For severe pain requiring IV management:

  • IV morphine: Start with 0.1 mg/kg IV, then 0.05 mg/kg at 30 minutes (maximum 10mg per dose) 1
  • IV hydromorphone: 1mg initially, then additional 1mg after 15 minutes if needed 1
  • IV fentanyl: 1 μg/kg initially, then approximately 30mcg every 5 minutes as needed 1

Special Considerations

For Acute Low Back Pain

• First-line: NSAIDs or acetaminophen 1
• Consider spinal manipulation by trained providers 1
• Avoid routine imaging unless red flags are present 1

For Patients on Opioid Agonist Therapy

• Continue usual maintenance dose of methadone or buprenorphine 1
• Verify dose with prescribing physician or clinic 1
• Use conventional analgesics including opioids at higher doses if needed due to cross-tolerance 1
• Avoid mixed agonist-antagonist opioids (pentazocine, nalbuphine, butorphanol) as they may precipitate withdrawal 1

Evidence Quality and Pitfalls

• The evidence strongly supports NSAIDs and acetaminophen as first-line agents for acute pain 2, 4, 6
• Higher doses of ibuprofen (>400mg) provide only modest additional analgesia with increased risk of adverse effects 4
• Common pitfalls include:
  • Undertreatment of pain, which may lead to decreased responsiveness to analgesics 1
  • Overreliance on opioids for mild to moderate pain 2, 6
  • Failure to use scheduled dosing rather than as-needed for predictable pain 1

Multimodal Approach for Refractory Pain

• For pain unresponsive to single agents, combine medications targeting different pain pathways:
  • Acetaminophen + NSAID combination
  • Consider short-term opioid use only for severe pain unresponsive to other measures 6, 7
  • Limit opioid prescriptions to shortest effective duration to prevent dependence 6

Remember that most acute pain is self-limited and improves with time regardless of treatment 1. The goal is to provide adequate analgesia while minimizing adverse effects during the recovery period.