What is the Morphine Equivalent Daily Dose (MEDD) for an adult patient with severe chronic pain or cancer on 1200mcg of fentanyl (equivalent to 100mcg of morphine per 1mcg of fentanyl) over 24 hours?

Morphine Equivalent Daily Dose for Fentanyl 1200 mcg/24h

Fentanyl 1200 mcg/24 hours (50 mcg/hour transdermal patch) converts to approximately 120 mg oral morphine equivalent daily dose (MEDD). 1

Conversion Methodology

Direct FDA-Approved Conversion

• The FDA drug label for transdermal fentanyl provides explicit conversion tables showing that fentanyl 50 mcg/hour (1200 mcg/24h) corresponds to 135-224 mg/day of oral morphine, with the recommended starting dose being conservative at the lower end of this range. 1
• Using the FDA's Table E, 1200 mcg/24h fentanyl (50 mcg/hour patch) equates to approximately 135-224 mg oral morphine per day. 1

Step-by-Step Calculation

• Step 1: Identify the fentanyl dose: 1200 mcg/24 hours = 50 mcg/hour transdermal delivery rate. 1
• Step 2: Apply FDA conversion table: 50 mcg/hour fentanyl patch = 135-224 mg oral morphine daily (conservative estimate ~120-135 mg for initial conversion). 1
• Step 3: The midpoint of this range is approximately 180 mg oral morphine daily, though the FDA recommends starting at the lower end (120-135 mg) to minimize overdose risk. 1

Critical Conversion Principles

Conservative Dosing Approach

• The FDA explicitly warns that Table C and Table E should NOT be used to convert FROM fentanyl transdermal system TO other therapies, as this conversion to fentanyl is intentionally conservative and using it in reverse can overestimate the dose of the new agent, leading to possible overdosage. 1
• When converting from fentanyl to another opioid, reduce the calculated equianalgesic dose by 25-50% to account for incomplete cross-tolerance. 2, 3

Pharmacokinetic Considerations

• Transdermal fentanyl creates a dermal depot that results in serum concentrations peaking 12-24 hours after initial application and maintaining relatively constant levels for 72 hours. 1, 4
• After patch removal, serum fentanyl half-life is prolonged (16-21 hours) due to continued absorption from the intradermal depot. 5, 4
• When discontinuing fentanyl patches, the new opioid should be initiated 12-18 hours after patch removal to account for this depot effect. 1

Practical Clinical Application

For Conversion to Oral Morphine

• Starting dose: 120-135 mg oral morphine daily (divided into 6 doses of 20-22.5 mg every 4 hours for immediate-release, or 60-67.5 mg every 12 hours for sustained-release). 1
• Provide immediate-release morphine 10-20% of total daily dose (12-27 mg) every 1-2 hours as needed for breakthrough pain. 2
• Reassess within 24 hours and titrate upward by 25-50% if pain control is inadequate. 2

Common Pitfall to Avoid

• Do not use the FDA conversion tables in reverse direction—they are designed for converting TO fentanyl, not FROM fentanyl, and will overestimate the required dose of the new opioid. 1
• The 50% of patients who required dose increases when converting TO fentanyl suggests the conversion is conservative; therefore, when converting FROM fentanyl, expect to need the higher end of the calculated range. 1

Alternative Opioid Conversions

• To IV morphine: 1200 mcg/24h fentanyl ≈ 40-45 mg IV morphine daily (using 3:1 oral to IV ratio), reduced by 25-50% for cross-tolerance = 20-34 mg IV morphine daily. 2, 1
• To hydromorphone: First convert to morphine equivalent (120-135 mg oral morphine), then divide by 7.5 = 16-18 mg oral hydromorphone daily. 6, 7