What are the recommended pain medications for acute pain management?

Recommended Pain Medications for Acute Pain Management

For acute pain management, non-opioid therapies including NSAIDs and acetaminophen should be used first-line, with opioids reserved for severe pain when benefits outweigh risks. 1

Pain Medication Selection Algorithm

For Mild to Moderate Acute Pain:

• First-line options:

  • Non-COX specific NSAIDs (e.g., ibuprofen 400-600 mg orally every 4-6 hours) are recommended over codeine-acetaminophen combinations 1
  • NSAIDs have better numbers needed to treat (2.7 for naproxen/ibuprofen vs 4.4 for codeine-acetaminophen) 1
  • NSAIDs provide longer time to re-medication with safer side effect profiles 1, 2
  • Acetaminophen 1000 mg (oral or IV) is an effective alternative, especially when NSAIDs are contraindicated 3, 2

• Second-line options:

  • COX-2 specific NSAIDs (e.g., celecoxib) are recommended over codeine-acetaminophen combinations 1
  • Oxycodone-acetaminophen is marginally superior to codeine-acetaminophen if opioid therapy is needed 1

For Moderate to Severe Acute Pain:

• First-line IV options:

  • Hydromorphone (0.015 mg/kg IV) is recommended over morphine for severe pain 1

    • Quicker onset of action compared to morphine 1
    • Lower risk of toxicity in renal failure 1
    • More potent at smaller doses (1.5 mg hydromorphone vs 10 mg morphine) 1

  • Fentanyl (1 mcg/kg initially, then ~30 mcg every 5 minutes) is recommended over morphine 1

    • Shorter onset of action and 100 times more potent than morphine 1
    • Higher bioavailability due to lipid solubility 1
    • Can be used in patients with morphine allergies 1

• Patient-controlled dosing:

  • Hydromorphone 1 mg + 1 mg patient-driven protocol is recommended over physician-driven protocols 1
    • Especially helpful for patients unable to clearly communicate pain levels 1

Special Considerations

For Patients with Renal Impairment:

• Use all opioids with caution at reduced doses and frequency 1
• Fentanyl and buprenorphine (transdermal or IV) are the safest opioids for patients with chronic kidney disease stages 4 or 5 1

For Patients on Maintenance Opioid Therapy:

• Continue maintenance methadone therapy and add short-acting opioid analgesics when needed 1
• For patients on buprenorphine maintenance:
  • Continue buprenorphine and titrate short-acting opioid analgesics to effect, OR
  • Divide the daily buprenorphine dose and administer every 6-8 hours to utilize its analgesic properties 1

For Neuropathic Pain:

• First-line options include:
  • Secondary-amine tricyclic antidepressants (nortriptyline, desipramine)
  • Selective serotonin norepinephrine reuptake inhibitors (duloxetine, venlafaxine)
  • Calcium channel α-2-δ ligands (gabapentin, pregabalin)
  • Topical lidocaine for localized peripheral neuropathic pain 1

Common Pitfalls and Caveats

• Acetaminophen ceiling effect: Acetaminophen reaches an analgesic ceiling effect at 1000 mg; increasing to 2000 mg provides minimal additional benefit 4
• IV vs. oral administration: IV acetaminophen does not reduce morphine requirements compared to placebo in ED patients 5
• Codeine metabolism variations: Certain genotypes may not metabolize or may hyper-metabolize codeine due to CYP2D6 polymorphism, affecting efficacy and safety 1
• Combination products: Fixed-dose combinations of opioids with acetaminophen should be limited to avoid acetaminophen-induced hepatic toxicity in patients requiring large doses 1
• Opioid use: When opioids are necessary for severe pain, they should be prescribed at the lowest effective dose and for no longer than the expected duration of severe pain 1
• Oral loading strategy: Oral oxycodone solution (0.125 mg/kg) can provide similar pain relief to IV morphine (0.1 mg/kg) after 30 minutes, with shorter administration time but delayed onset 6