What is the morphine (ME) equivalent for a fentanyl (Duragesic) patch and hydromorphone (Dilaudid)?

Morphine Equivalents for Fentanyl Patch and Hydromorphone

For fentanyl transdermal patches, use approximately 100:1 ratio (oral morphine mg/day : fentanyl mcg/hour), and for hydromorphone, use a 5:1 ratio (oral morphine : oral hydromorphone) or 3:1 ratio (oral morphine : parenteral hydromorphone). 1, 2

Fentanyl Transdermal Patch Conversion

Standard Conversion Ratios

• The FDA-approved conversion uses approximately 100:1 ratio where 60-134 mg/day oral morphine converts to 25 mcg/hour fentanyl patch 2
• For 135-224 mg/day oral morphine, use 50 mcg/hour fentanyl patch 2
• For 225-314 mg/day oral morphine, use 75 mcg/hour fentanyl patch 2
• For 315-404 mg/day oral morphine, use 100 mcg/hour fentanyl patch 2

Parenteral Fentanyl to Transdermal Conversion

• When converting from continuous IV fentanyl infusion to transdermal fentanyl, use a straight 1:1 ratio (mcg of parenteral fentanyl = mcg/hour of transdermal fentanyl) 1, 3
• Some patients may require patch replacement every 48 hours instead of the standard 72 hours 1

Important Caveats for Fentanyl Conversion

• The conversion ratio varies significantly with dose: at lower morphine doses, the ratio may be closer to 28:1 to 39:1, while at higher doses it approaches 47:1 4
• Research suggests that for low-dose conversions (morphine 16.6 mg/day), the ratio is approximately 28:1, not the commonly cited 50:1 or 100:1 4
• Always reduce the calculated equianalgesic dose by 25-50% when switching between opioids to account for incomplete cross-tolerance 1, 5
• Heat sources (heating pads, electric blankets) accelerate fentanyl absorption and are contraindicated 1

Hydromorphone Conversion

Oral Hydromorphone

• Oral morphine to oral hydromorphone ratio is approximately 5:1 2
• 8-17 mg/day oral hydromorphone = 25 mcg/hour fentanyl patch 2
• 17.1-28 mg/day oral hydromorphone = 50 mcg/hour fentanyl patch 2
• 28.1-39 mg/day oral hydromorphone = 75 mcg/hour fentanyl patch 2
• 39.1-51 mg/day oral hydromorphone = 100 mcg/hour fentanyl patch 2

Parenteral Hydromorphone

• Oral morphine to IV/IM hydromorphone ratio is approximately 3:1 (oral:parenteral) 2
• 1.5-3.4 mg/day IV hydromorphone = 25 mcg/hour fentanyl patch 2
• 3.5-5.6 mg/day IV hydromorphone = 50 mcg/hour fentanyl patch 2
• 5.7-7.9 mg/day IV hydromorphone = 75 mcg/hour fentanyl patch 2
• 8-10 mg/day IV hydromorphone = 100 mcg/hour fentanyl patch 2

Clinical Considerations for Hydromorphone

• Hydromorphone is preferred for patients with significant morphine adverse effects or severe renal dysfunction 6
• When converting to subcutaneous or IV morphine from oral, use a 3:1 ratio (oral:parenteral) 5

Critical Safety Principles

Dose Reduction for Cross-Tolerance

• Always reduce the calculated equianalgesic dose by 25-50% when rotating between different opioids 1, 5
• The CDC warns against using calculated morphine equivalent doses directly without this reduction 5

Conversion Table Limitations

• These conversion tables are unidirectional: they convert TO fentanyl patch but should NOT be used to convert FROM fentanyl patch to other opioids, as this will overestimate the new opioid dose and risk fatal overdose 2
• There is significant inter-patient variability in opioid potency—it is safer to underestimate requirements and provide rescue medication than to overestimate 2
• Significant variation exists among clinicians in performing these conversions, particularly for fentanyl and methadone 7

Breakthrough Pain Management

• Prescribe additional doses of approximately 10-20% of the 24-hour dose for breakthrough pain 5
• More frequent assessment and titration are needed for actively dying patients 5