What is the equivalent oral hydromorphone (Dilaudid) dose for a patient receiving 90 mg of intravenous (IV) morphine (Morphine sulfate)?

Converting IV Morphine to Oral Hydromorphone

The equivalent oral hydromorphone dose for a patient receiving 90 mg of IV morphine is approximately 30 mg of oral hydromorphone. This conversion requires multiple steps and understanding of opioid equivalency principles.

Conversion Process

1. Step 1: Convert IV morphine to oral morphine

   • According to NCCN guidelines, IV morphine is approximately 3 times more potent than oral morphine 1
   • 90 mg IV morphine × 3 = 270 mg oral morphine equivalent

2. Step 2: Convert oral morphine to oral hydromorphone

   • The conversion ratio from oral morphine to oral hydromorphone is approximately 5:1 to 7:1
   • Using the more recent evidence from 2, which found that IV hydromorphone to oral morphine equivalent daily dose (MEDD) has a ratio of approximately 11.5:1
   • When we account for IV hydromorphone being 2.5 times more potent than oral hydromorphone 2, we can calculate:
     • IV hydromorphone to oral hydromorphone ratio = 2.5:1
     • IV hydromorphone to oral morphine ratio = 11.5:1
     • Therefore, oral hydromorphone to oral morphine ratio = 11.5 ÷ 2.5 = 4.6:1 (approximately 5:1)
   • 270 mg oral morphine ÷ 5 = 54 mg oral hydromorphone

3. Step 3: Adjust for cross-tolerance

   • When converting between different opioids, a dose reduction of 25-50% is recommended due to incomplete cross-tolerance 1
   • 54 mg × (1 - 0.25 to 0.5) = 27-40.5 mg oral hydromorphone
   • A conservative starting dose would be approximately 30 mg oral hydromorphone

Important Clinical Considerations

• Individualize based on patient factors:

  • Elderly patients or those with renal/hepatic impairment may require further dose reduction (25-50% lower) 1
  • Higher previous opioid doses may require different conversion ratios - patients on higher doses (≥30 mg/day of IV hydromorphone) may require lower conversion ratios 2

• Monitoring is essential:

  • Monitor vital signs, pain scores, and sedation levels closely after conversion
  • Respiratory rate should remain ≥8/min 1
  • Be prepared to adjust dosing based on clinical response

• Common pitfalls to avoid:

  • Using fixed conversion ratios without considering patient factors can lead to under or overdosing 1
  • Failing to account for incomplete cross-tolerance between different opioids
  • Not implementing prophylactic measures for constipation, which is almost always required with opioid therapy 1

• Dosing schedule:

  • The total daily dose should be divided into appropriate intervals based on the formulation used
  • Immediate-release: typically every 4-6 hours
  • Extended-release: typically every 12-24 hours depending on the product

This conversion represents a starting point for dosing, with close monitoring and dose adjustments based on the patient's clinical response being essential for optimal pain management and safety.