What is the appropriate dose of fentanyl (transdermal fentanyl) patch when transitioning a patient from a Butrans (buprenorphine) patch 7.5 mcg/hour to a fentanyl patch?

Transitioning from Butrans (Buprenorphine) 7.5 mcg/hour to Fentanyl Patch

A fentanyl 12.5 mcg/hour patch is the appropriate transitional dose when converting from a Butrans 7.5 mcg/hour patch, and you should remove the Butrans patch and apply the fentanyl patch simultaneously without a waiting period. 1

Conversion Calculation and Rationale

The conversion ratio from buprenorphine to fentanyl is approximately 1:1.25-1.7, meaning a buprenorphine 7.5 mcg/hour patch equates to roughly 10-13 mcg/hour of fentanyl. 1 Since the closest commercially available fentanyl patch strength is 12.5 mcg/hour, this is the appropriate starting dose for your patient. 1

Important Note on Dosing

• The 12.5 mcg/hour fentanyl patch represents a conservative conversion that accounts for incomplete cross-tolerance between different opioids 1
• This patient on buprenorphine 7.5 mcg/hour qualifies as opioid-tolerant, which is a requirement for fentanyl patch use 2, 1

Transition Protocol

Step 1: Simultaneous Switch

• Remove the Butrans patch and apply the fentanyl 12.5 mcg/hour patch at the same time 1
• No waiting period is required between removing buprenorphine and starting fentanyl 1

Step 2: Breakthrough Medication Coverage

• Prescribe short-acting opioid breakthrough medication for the first 8-24 hours until fentanyl reaches steady state 2, 3, 1
• This is critical because fentanyl levels continue rising during the first 24 hours after patch application 3

Step 3: Monitoring Timeline

• Reassess pain control after 2-3 days when fentanyl reaches steady state 1, 4
• Do not increase the fentanyl dose for at least 3 days after initial application 4
• The fentanyl patch duration is typically 72 hours, though some patients require 48-hour replacement 2, 1

Step 4: Dose Titration

• After 2-3 days, adjust the dose based on average daily breakthrough medication requirements 1
• Subsequent dose adjustments should occur no more frequently than every 6 days 4

Critical Safety Considerations for Hospice Patients

Absolute Contraindications

• Never apply heat to the fentanyl patch site (no heating pads, electric blankets, heat lamps, or fever management with external heat) as this accelerates absorption and can cause fatal overdose 2, 3, 1

Special Considerations for Cachectic Patients

• If your hospice patient is cachectic, anticipate the need for 25-50% higher patch doses due to impaired absorption 3
• Consider more frequent patch changes (every 48 hours) if pain control wanes 3

Common Pitfalls to Avoid

• Do not use conversion tables designed for other opioids to calculate buprenorphine-to-fentanyl conversions, as buprenorphine has unique pharmacology 1
• Do not wait for buprenorphine to "wash out" before starting fentanyl—this will cause unnecessary pain in a hospice patient 1
• Do not use the FDA conversion tables (which start at 25 mcg/hour fentanyl for 60-134 mg/day oral morphine) as these are designed for full agonist opioids, not buprenorphine 4