IV Hydromorphone to Oral Oxycodone Conversion
Oral oxycodone dosing can be calculated from an equianalgesic chart using the relationship of parenteral hydromorphone 1.5 mg = 10 mg parenteral morphine, and oral oxycodone 20 mg = 10 mg parenteral morphine. [1] When switching to a new opioid, the calculated equianalgesic oral oxycodone dose should be reduced due to incomplete cross-tolerance. [1], [2]
Equianalgesic Conversion Ratio (Normal Hepatic and Renal Function)
- Equianalgesic oral oxycodone (mg/24 h) = total IV hydromorphone (mg/24 h) × 13.3. [1]
- Derivation from chart values: 1.5 mg parenteral hydromorphone ≙ 20 mg oral oxycodone. [1]
Cross-Tolerance Dose Reduction When Switching
- Initial oral oxycodone dose should be 50% to 67% of the equianalgesic calculated dose for incomplete cross-tolerance. [2]
- A reduction range of 30% to 50% is also recommended when converting to a different opioid due to incomplete cross-tolerance. [1]
Practical Adult Opioid-Tolerant Conversion Algorithm
- Step 1: Calculate total IV hydromorphone delivered over 24 hours (mg/24 h) including basal infusion and IV boluses. [1]
- Step 2: Convert to equianalgesic oral oxycodone (mg/24 h) using × 13.3. [1]
- Step 3: Apply reduction for incomplete cross-tolerance using × 0.50 to 0.67. [1], [2]
Conversion Expressed as Per-1 mg IV Hydromorphone (24 h Total)
- Equianalgesic oral oxycodone: 13.3 mg PO oxycodone per 1 mg IV hydromorphone (over 24 h). [1]
- Initial oral oxycodone after reduction: 6.7 mg to 9.0 mg PO oxycodone per 1 mg IV hydromorphone (over 24 h). [1], [2]
Initiation and Titration Expectations
- Oral oxycodone dosing should be titrated to individual response after conversion. [1]
- Rescue (short-acting) opioid dosing is typically required during the early conversion period because analgesia response may lag behind scheduled dose changes. [2]
Common Pitfalls to Avoid
- Using equianalgesic doses without a cross-tolerance reduction increases risk of opioid adverse effects during opioid rotation. [1], [2]
- Failing to account for the total 24-hour IV opioid exposure (basal infusion plus demand/bolus doses) results in under- or overestimation of the conversion target. [1]
Targeting Safe Dose Frequency
- Oral oxycodone dosing is commonly scheduled in divided doses rather than a single daily dose when converting from IV opioid regimens. [1]
- Dose selection should align with the intended oxycodone formulation and the 24-hour conversion target. [1]