What is the recommended approach to transfer a patient from hydromorphone (opioid analgesic) 4 mg to oxycodone (opioid analgesic)?

Converting from Hydromorphone 4 mg to Oxycodone

When converting a patient from hydromorphone 4 mg to oxycodone, no washout period is required, but the dose should be reduced by 25-50% from the calculated equianalgesic dose to account for incomplete cross-tolerance. 1

Conversion Process

1. Calculate total daily hydromorphone dose:

   • Determine the 24-hour hydromorphone requirement (e.g., 4 mg) 1

2. Calculate equianalgesic oxycodone dose:

   • Using the conversion ratio of 1:5 (oral hydromorphone:oral oxycodone)
   • 4 mg oral hydromorphone = 20 mg oral oxycodone 1, 2

3. Adjust for incomplete cross-tolerance:

   • Reduce the calculated equianalgesic dose by 25-50% 1
   • 20 mg oxycodone reduced by 25-50% = 10-15 mg oxycodone daily 1

4. Determine dosing schedule:

   • Divide the total daily oxycodone dose by the number of doses per day 1
   • For immediate-release oxycodone: typically every 4-6 hours 3
   • For example: 10-15 mg daily ÷ 4 doses = 2.5-3.75 mg per dose 1

Important Clinical Considerations

• No washout period needed: Direct conversion is appropriate as both are pure opioid agonists 1

• Monitor closely: Especially during the first 24-72 hours after conversion for signs of under or overdosing 3

• Breakthrough pain management: Provide short-acting opioid rescue doses (typically 10-15% of total daily dose) during transition 1

• Individualized titration: After initial conversion, titrate dose based on pain control and side effects 3

• Efficacy equivalence: Studies show hydromorphone and oxycodone have comparable efficacy and safety profiles when dosed appropriately 4, 5

Potential Pitfalls and Cautions

• Avoid using fixed conversion ratios without clinical judgment: Patient variability means suggested doses are approximate 1

• Consider patient-specific factors:

  • Age, renal/hepatic function, and comorbidities may affect dosing 3
  • CYP2D6 metabolism status can impact oxycodone efficacy 6

• Avoid underdosing: If pain was poorly controlled on hydromorphone, consider using 100% of the equianalgesic dose or increase by 25% 1

• Avoid overdosing: If transitioning due to side effects, use the lower end of the dose reduction range (50%) 1

• Regular reassessment: Continually reevaluate pain control and adverse effects 3