What is the equivalent dosage of 40mg oxycodone to Dilaudid (hydromorphone)?

Opioid Conversion: Oxycodone 40mg to Hydromorphone (Dilaudid)

Direct Answer

40mg of oral oxycodone converts to approximately 4mg of oral hydromorphone (Dilaudid), but you should start with 2-3mg oral hydromorphone (50-75% dose reduction) to account for incomplete cross-tolerance. 1

Conversion Calculation

Step 1: Convert to Morphine Milligram Equivalents (MME)

• Oxycodone has a conversion factor of 1.5 to morphine equivalents 1
• 40mg oxycodone × 1.5 = 60 MME per day 1, 2, 3

Step 2: Convert MME to Hydromorphone

• Hydromorphone has a conversion factor of 5.0 (meaning hydromorphone is 5 times more potent than morphine) 1
• 60 MME ÷ 5.0 = 12mg oral hydromorphone per day 1, 3
• However, if this is a single 40mg dose (not daily total), then: 40mg oxycodone = 60 MME ÷ 5.0 = 12mg hydromorphone total daily dose

For a Single Dose Equivalent

• If 40mg oxycodone is a single dose given 3 times daily (120mg total daily), the calculation differs
• For a direct single-dose conversion: 40mg oxycodone ÷ 10 = 4mg hydromorphone (using the approximate 10:1 oral oxycodone to oral hydromorphone ratio) 1

Critical Safety Reduction

You must reduce the calculated equianalgesic dose by 25-50% when switching opioids 1, 2, 3

Recommended Starting Doses:

• Conservative approach (50% reduction): Start with 2mg oral hydromorphone 1, 3
• Moderate approach (25-37.5% reduction): Start with 2.5-3mg oral hydromorphone 1, 2
• This reduction accounts for incomplete cross-tolerance between different opioids and individual pharmacokinetic variability 1

Route-Specific Considerations

If Converting to IV/Subcutaneous Hydromorphone:

• Oral hydromorphone is approximately 5 times less potent than IV hydromorphone 3, 4
• 4mg oral hydromorphone ≈ 0.8mg IV hydromorphone 3, 4
• With 50% safety reduction: start with 0.4mg IV hydromorphone 3, 4

Clinical Implementation Algorithm

For Controlled Pain on Current Regimen:

1. Calculate full equianalgesic dose (4mg oral hydromorphone for 40mg oxycodone) 1
2. Reduce by 50%: Start with 2mg oral hydromorphone 1, 3
3. Provide immediate-release hydromorphone 0.5-1mg every 4 hours PRN for breakthrough 2, 3
4. Reassess within 24-48 hours and titrate based on breakthrough medication use 2, 3

For Poorly Controlled Pain:

1. May start with 100% of equianalgesic dose or increase by 25% 1
2. Start with 4-5mg oral hydromorphone 1, 3
3. Monitor closely for respiratory depression 3

Important Caveats and Pitfalls

Variability in Conversion Ratios:

• The oxycodone to hydromorphone ratio ranges from approximately 8:1 to 10:1 in the literature 5, 6
• Significant variability exists between clinicians and conversion resources, with standard deviations often exceeding 50% of mean values 6
• These are estimates only and cannot account for individual genetics and pharmacokinetics 1

High-Dose Considerations:

• At higher opioid doses (≥30mg IV hydromorphone equivalent), lower conversion ratios may be needed 4
• The conversion ratio from IV hydromorphone to oral morphine equivalents decreases from 11.54 to 9.86 at doses ≥30mg/day 4

Monitoring Requirements:

• Close monitoring for respiratory depression and oversedation is essential after any opioid conversion 3
• Reassess pain control and adverse effects within 24-48 hours 2, 3
• Adjust dose based on breakthrough medication requirements 2, 3

Patient-Specific Factors to Consider:

• Age, renal/hepatic function, and prior opioid exposure affect dosing 3
• Previous opioid dose influences conversion ratios when switching 5
• Reasons for switching (inadequate analgesia vs. adverse effects) impact appropriate dosing 5