What alternative medication can be used if oral hydromorphone (Dilaudid) is not sufficient to control pain?

Management of Inadequate Pain Control with Oral Hydromorphone

When oral hydromorphone (Dilaudid) fails to control pain adequately, switch to an alternative strong opioid—specifically morphine, oxycodone, or methadone (if experienced prescriber)—or change the route of administration to parenteral hydromorphone or transdermal fentanyl for stable pain. 1

Primary Strategy: Opioid Rotation

The most effective approach is opioid rotation (switching to a different opioid), which improves pain control and/or reduces side effects in patients who fail to achieve adequate analgesia with oral hydromorphone. 1, 2

First-Line Alternative Opioids

• Morphine (oral): The gold standard strong opioid and most widely recommended first-line alternative 1

  • Available in both immediate-release and modified-release formulations 1
  • Oral morphine is approximately 7.5 times less potent than oral hydromorphone 1
  • Starting dose without pretreatment: 20-40 mg oral morphine 1

• Oxycodone (oral): Equally effective alternative to morphine 1, 2

  • Available in immediate-release and modified-release formulations 1
  • Better systemic bioavailability (60-90%) than morphine 1
  • Oral oxycodone is approximately 1.5-2 times more potent than oral morphine 1
  • Equianalgesic dose is between half and two-thirds that of oral morphine 1

Conversion Calculation Method

Follow this three-step process when rotating from oral hydromorphone to another opioid: 1, 2

1. Calculate total 24-hour hydromorphone dose currently being taken 1

2. Convert to equianalgesic dose of new opioid using conversion ratios:

   • Oral hydromorphone to oral morphine: multiply by 7.5 1
   • Oral hydromorphone to oral oxycodone: multiply by approximately 5 1

3. Reduce the calculated dose by 25-50% to account for incomplete cross-tolerance between opioids 1, 2

   • Use 50% reduction if pain was well-controlled but side effects were intolerable 2
   • Use 25% reduction if pain control was inadequate 1, 2
   • If pain was poorly controlled, may start with 100% of equianalgesic dose or increase by 25% 1

Critical Caveat on Conversion Ratios

Conversion ratios are approximate guides only—individual patient response varies considerably, requiring careful clinical monitoring and dose adjustment after switching. 1, 3, 2 The relative effectiveness varies substantially in published literature and among individual patients, so switching should be done cautiously with dose reduction of the newly prescribed opioid 1

Alternative Strategy: Route Change

Parenteral Hydromorphone

If the issue is inadequate oral absorption or first-pass metabolism rather than the drug itself, convert to IV or subcutaneous hydromorphone. 1

• Conversion ratio: Oral to parenteral hydromorphone is approximately 5:1 3
• Parenteral hydromorphone allows smaller volume administration, which may be beneficial 3
• IV/subcutaneous route bypasses first-pass metabolism 1

Transdermal Fentanyl

For patients with stable opioid requirements who cannot tolerate oral medications, transdermal fentanyl is an effective alternative. 1

• Best reserved for stable pain (not fluctuating requirements) 1
• Particularly useful for patients unable to swallow, poor morphine tolerance, or poor compliance 1
• Onset of analgesic effect: 8-16 hours; steady state achieved at 72 hours 1
• Conversion from oral hydromorphone: Use established conversion tables 1
  • Example: 7.5 mg/day oral hydromorphone ≈ 25 mcg/h transdermal fentanyl 1
• Critical pitfall: Breakthrough medication must be prescribed during first 24 hours and continued until patch stabilizes 1

Advanced Alternative: Methadone

Methadone is an effective alternative but should ONLY be initiated by physicians with specific experience and expertise in its use. 1, 2

• Marked interindividual differences in plasma half-life (17 to >100 hours) and duration of action make dosing complex 1
• Conversion ratios vary widely (4:1,8:1, or 12:1 depending on baseline opioid dose) 1, 2
• Drug accumulates on chronic dosing—should not be dosed more frequently than every 8 hours 1
• Difficult to accurately determine equianalgesic dose when switching, particularly in opioid-tolerant patients 1

Expected Outcomes and Monitoring

Up to 40% of patients with cancer pain require opioid rotation during their treatment course. 1, 2 All available evidence (though largely observational) concludes that opioid switching is a useful clinical maneuver for improving pain control and/or reducing opioid-related side effects 4

Post-Conversion Monitoring

• Monitor closely for both efficacy and adverse effects after any opioid conversion 3, 2
• Titrate liberally and rapidly to analgesic effect during the first 24 hours 1
• Provide immediate-release opioid for breakthrough pain during titration 1

When Opioid Rotation Fails

Only 1-2% of cancer pain patients require spinal (epidural or intrathecal) analgesia. 1, 2 This should be reserved for patients refractory to all conventional strategies and/or with dose-limiting analgesic-related side effects 1, 2

Common Pitfalls to Avoid

• Never assume equianalgesic ratios are precise—they are approximations requiring clinical judgment 1, 3, 2
• Always reduce the calculated dose when switching opioids to account for incomplete cross-tolerance 1, 3, 2
• Do not use transdermal fentanyl for unstable or rapidly escalating pain—it lacks flexibility for dose titration 1
• Avoid methadone unless you have specific expertise—its complex pharmacokinetics create significant risk 1, 2
• Do not forget breakthrough medication when initiating transdermal fentanyl 1