What are the indications and dosing guidelines for morphine (Morphine) vs Dilaudid (Hydromorphone) vs Tramadol vs Percocet (Oxycodone/Acetaminophen) vs OxyContin (Oxycodone) for pain management?

Opioid Selection for Pain Management: A Practical Guide

The optimal opioid choice depends on pain severity, with tramadol recommended for mild-moderate pain, morphine as first-line for moderate-severe pain, hydromorphone preferred in emergency settings, and oxycodone formulations for specific clinical scenarios. 1, 2

Pain Severity-Based Selection Algorithm

Mild to Moderate Pain (WHO Step I-II)

• First-line: Non-opioid analgesics (acetaminophen, NSAIDs)

  • Acetaminophen: 500-1000mg every 6 hours (max 4000mg/day)
  • Ibuprofen: 400-600mg every 6 hours (max 3200mg/day) 1

• Second-line: Weak opioids or low-dose strong opioids

  • Tramadol: 50-100mg every 4-6 hours (max 400mg/day)
    • Advantages: Lower risk of respiratory depression, less constipation than other opioids
    • Disadvantages: Serotonin syndrome risk with certain medications, seizure risk 1, 3

Moderate to Severe Pain (WHO Step III)

• First-line: Morphine

  • Oral: Starting dose 20-40mg/day in divided doses for opioid-naïve patients
  • IV/SC: Starting dose 5-10mg (one-third of oral dose) 1
  • Advantages: Gold standard, well-established efficacy, multiple formulations
  • Disadvantages: Active metabolites accumulate in renal impairment 1

• Alternative: Hydromorphone

  • 7.5 times more potent than oral morphine
  • Recommended in emergency settings (0.015 mg/kg IV) over morphine (0.1 mg/kg IV)
  • Advantages: Quicker onset of action, less histamine release, better for renal impairment 1, 2

• Alternative: Oxycodone

  • 1.5-2 times more potent than oral morphine
  • Available as immediate-release or controlled-release formulations
  • Often combined with acetaminophen (Percocet) for enhanced analgesia 1, 4

• Alternative: OxyContin (controlled-release oxycodone)

  • For continuous, around-the-clock pain management
  • Not for as-needed pain relief or immediate post-operative pain
  • Dosing typically every 12 hours 1

Clinical Scenario-Based Selection

Emergency Department Pain Management

• Hydromorphone (0.015 mg/kg IV) is recommended over morphine due to:
  • Quicker onset of action
  • Lower risk of dose stacking
  • Less risk of toxicity in renal failure
  • More potent at lower volume (1.5mg hydromorphone vs 10mg morphine) 1

Cancer Pain Management

• Morphine remains first-line for moderate to severe cancer pain
• Fentanyl (transdermal) for stable pain in patients unable to take oral medications
• Methadone as alternative but requires expertise due to complex pharmacokinetics 1, 2

Combination Products

• Percocet (oxycodone/acetaminophen) superior to codeine/acetaminophen combinations
  • Better pain relief
  • Lower incidence of side effects 1, 4
• Consider for moderate pain when single agents insufficient 4

Route of Administration Considerations

• Oral: Preferred when possible
• IV: For severe acute pain requiring rapid relief
• Transdermal: For stable chronic pain in patients unable to take oral medications
• Subcutaneous: When IV access unavailable (use 1/3 of oral dose) 1, 2

Special Populations

Renal Impairment

• Avoid/use with caution: Morphine, hydrocodone, oxymorphone, codeine
• Preferred options: Fentanyl, hydromorphone (with dose adjustment) 1, 2

Elderly

• Start at lower doses (25-50% of standard adult dose)
• Titrate more slowly
• Monitor more frequently for adverse effects 2

Adverse Effects Management

• Constipation: Implement prophylactic bowel regimens with stimulant laxatives
• Nausea/vomiting: Metoclopramide or antidopaminergic drugs
• Respiratory depression: Monitor closely, have naloxone available
• Sedation: Reduce dose; psychostimulants only after other methods fail 1, 2

Common Pitfalls to Avoid

1. Undertreatment of pain: Don't hesitate to use appropriate doses
2. Failure to prevent constipation: Always prescribe laxatives with opioids
3. Inappropriate conversion between opioids: Use established conversion tables
4. Overlooking renal function: Adjust doses or choose alternative opioids in renal impairment
5. Not accounting for previous opioid exposure: Opioid-tolerant patients need higher starting doses

Remember that regular reassessment of pain control and side effects is essential for optimal management of patients requiring opioid therapy.