Hydrocodone to Oxycodone Conversion
For a patient taking hydrocodone 30 mg daily, the equivalent oxycodone dose is approximately 20 mg daily, which should then be reduced by 25-50% to account for incomplete cross-tolerance, resulting in a starting dose of 10-15 mg oxycodone daily. 1
Conversion Methodology
The conversion process requires first calculating morphine milligram equivalents (MME) as an intermediate step, since direct hydrocodone-to-oxycodone conversion tables are not provided in standard guidelines 2:
Step 1: Calculate MME from Hydrocodone
- Hydrocodone 30 mg daily converts to morphine using a 1:1 ratio (hydrocodone is approximately equianalgesic to morphine orally) 2
- This yields 30 MME/day
Step 2: Convert MME to Oxycodone
- Using the CDC conversion factor of 1.5 for oxycodone to morphine 2, 3
- 30 MME ÷ 1.5 = 20 mg oxycodone daily
- This can be verified using NCCN conversion tables showing 60 mg oral morphine = 30 mg oral oxycodone 1
Step 3: Apply Safety Reduction
The calculated equianalgesic dose must be reduced by 25-50% when rotating between opioids 1, 2, 3:
- Conservative approach (50% reduction): Start with 10 mg oxycodone daily if pain was well-controlled on hydrocodone 3
- Moderate approach (25% reduction): Start with 15 mg oxycodone daily if pain control was suboptimal 3
Answering Your Specific Question
You asked about equivalence to three different oxycodone doses:
Oxycodone 10 mg daily: This represents a 50% dose reduction from the calculated equivalent and is the most appropriate starting dose for safe opioid rotation when pain was adequately controlled 1, 3
Oxycodone 20 mg daily: This is the calculated equianalgesic dose without safety reduction and should not be used as a starting dose due to risk of overdose from incomplete cross-tolerance 1, 2
Oxycodone 40 mg daily: This represents a dose escalation and is inappropriate for initial conversion—it would only be considered after titration if pain control remains inadequate 4
Critical Safety Considerations
Always reduce the calculated equianalgesic dose by 25-50% when rotating between opioids to account for 1, 2, 3:
- Incomplete cross-tolerance between different opioid molecules
- Individual pharmacokinetic variability
- Patient-specific factors (age, renal/hepatic function, prior opioid exposure)
Common pitfall to avoid: The significant variability in published equianalgesic conversion ratios means these calculations are estimates only 5, 6, 7. Research demonstrates that clinicians using different conversion resources can arrive at vastly different doses for the same patient 5.
Monitoring and Titration Protocol
After initiating oxycodone 10-15 mg daily 3, 4:
- Monitor closely for respiratory depression and oversedation in the first 24-72 hours 4
- Reassess pain control and side effects within 24-48 hours 3
- Provide breakthrough medication (typically 10-20% of total daily dose every 4-6 hours as needed) 1, 4
- Titrate upward based on breakthrough medication requirements if pain control is inadequate 3, 4
The oxycodone should be dosed every 4-6 hours for immediate-release formulations 4, which would be approximately 1.5-2.5 mg per dose if using the conservative 10 mg daily total.