Fentanyl transdermal patch conversion
Starting patch strength from the 24-hour oral morphine equivalent, per the FDA label table.
Inputs
0 of 1Use the MME calculator first if needed.
mg/day
When to use
- Converting an opioid-tolerant patient (at least 60 mg oral morphine per day for a week or longer) to a patch.
Pearls and pitfalls
- Never use in opioid-naive patients.
- The label table is deliberately conservative; provide short-acting breakthrough medication.
- Full effect takes 12 to 24 hours; do not titrate before 3 days.
- Fever and external heat increase absorption.
Why use
Uses the label's own table rather than a ratio, which avoids overdose.
Patch strength from the label's conversion table (24-h oral morphine → mcg/h)