What is the morphine equivalent for Dilaudid (hydromorphone)?

Morphine Equivalent for Dilaudid (Hydromorphone)

Hydromorphone has a conversion factor of 4, meaning 1 mg of hydromorphone equals 4 mg of morphine in morphine milligram equivalents (MME). 1

Standard Conversion Factors

The CDC Guideline for Prescribing Opioids establishes the following conversion ratios for hydromorphone to morphine equivalents: 1

• Oral hydromorphone: 1 mg = 4 mg oral morphine (conversion factor of 4)
• Parenteral (IV/SC) hydromorphone: The ratio is approximately 5:1 to 8.5:1 depending on the route

Route-Specific Conversions

Oral to Oral Conversion

• 1 mg oral hydromorphone = 4 mg oral morphine 1, 2
• Example: 8 mg oral hydromorphone daily = 32 mg oral morphine daily 1

Parenteral Conversions

• IV/SC hydromorphone to IV/SC morphine: Approximately 1:5 to 1:8.5 ratio 3, 4
• Research evidence suggests hydromorphone is 8.5 times more potent than morphine when given intravenously 3
• 10 mg IV morphine ≈ 1.2-2 mg IV hydromorphone 2, 3

Oral to Parenteral Hydromorphone

• Oral to IV/SC hydromorphone: Approximately 5:1 ratio 2
• 5 mg oral hydromorphone ≈ 1 mg IV/SC hydromorphone 2

Clinical Application Algorithm

When converting between morphine and hydromorphone: 2, 5

1. Calculate total daily dose of current opioid (including scheduled and breakthrough doses)
2. Apply conversion factor: Multiply hydromorphone dose by 4 to get MME
3. Reduce by 25-50% when switching between opioids to account for incomplete cross-tolerance 2, 5
4. Monitor closely within 24 hours for pain control and adverse effects 5

Critical Safety Considerations

These conversion factors are for calculating MME for comparison purposes only—when actually switching patients between opioids, reduce the calculated equianalgesic dose by 25-50% to prevent overdose. 1, 2

Important Caveats:

• Conversion ratios are estimates and cannot account for individual genetic and pharmacokinetic variability 1
• Hydromorphone may cause less pruritus than morphine but has similar other side effects 3, 4
• Both morphine and hydromorphone should be used cautiously in renal impairment due to accumulation of active metabolites 1, 2
• Higher doses of hydromorphone (≥30 mg/day IV) may require lower conversion ratios 6

Practical Dosing Examples

Example 1: Oral Conversion

• Patient on 2 mg oral hydromorphone every 4 hours (12 mg/day total)
• MME calculation: 12 mg × 4 = 48 MME/day 1, 2

Example 2: IV to Oral Conversion

• Patient on 1.5 mg IV hydromorphone
• Converts to approximately 60 mg oral morphine equivalent (1:40 ratio for this dose range) 5
• When switching, start with 25-50% reduction: 30-45 mg oral morphine 5

Example 3: Emergency Department Dosing

• Standard ED dose: 0.015 mg/kg IV hydromorphone is equivalent to 0.1 mg/kg IV morphine 4
• For a 70 kg patient: 1 mg IV hydromorphone ≈ 7 mg IV morphine 4