What is the equivalent fentanyl patch dose to a Butrans (buprenorphine) 10 mcg patch?

Butrans 10 mcg/h Buprenorphine Patch Equivalence to Fentanyl

A Butrans (buprenorphine) 10 mcg/h patch is approximately equivalent to a fentanyl 12.5 mcg/h patch, though this dose is not commercially available, so the closest available option would be a fentanyl 25 mcg/h patch with appropriate dose reduction and close monitoring.

Conversion Calculation

The conversion between buprenorphine and fentanyl patches requires working through oral morphine equivalents as an intermediary:

Step 1: Convert Buprenorphine to Oral Morphine Equivalent

• Buprenorphine 10 mcg/h patch converts to approximately 7.5-13 mg oral morphine per day using the recommended conversion ratio of 75:1 to 110:1 1
• For cancer pain patients or those requiring more aggressive dosing, the 75:1 ratio is more appropriate, yielding approximately 13 mg oral morphine equivalent per day 1
• Using the more conservative 100:1 ratio yields approximately 10 mg oral morphine equivalent per day 1

Step 2: Convert Oral Morphine to Fentanyl Patch

• The National Comprehensive Cancer Network recommends a 100:1 conversion ratio between oral morphine and transdermal fentanyl 2
• Using 10-13 mg oral morphine equivalent: this translates to approximately 0.1-0.13 mcg/h fentanyl, which when multiplied by 100 equals 10-13 mcg/h fentanyl patch 3, 4

Practical Clinical Application

Available Dosing Options

• The lowest commercially available fentanyl patch is 25 mcg/h 3, 4
• Since the calculated equivalent (10-13 mcg/h) is not available, you must either:
  • Start with fentanyl 25 mcg/h and reduce by 25-50% of the calculated dose to account for incomplete cross-tolerance 3, 4
  • Consider that the patient may be under-dosed on buprenorphine 10 mcg/h if requiring conversion

Critical Safety Considerations

When converting from buprenorphine to fentanyl, you must account for buprenorphine's unique pharmacology:

• Buprenorphine has extremely high mu-receptor affinity and dissociates slowly, which can block other opioids from binding 5
• Allow adequate washout time (at least 24-48 hours) after removing the buprenorphine patch before applying fentanyl to avoid reduced fentanyl efficacy 6
• Residual buprenorphine in the skin continues absorption for hours after patch removal 6

Monitoring Protocol

• Provide short-acting opioid breakthrough medication for the first 8-24 hours until steady state is achieved 3, 4
• Reassess pain control after 2-3 days when fentanyl reaches steady state 3, 4
• Titrate based on average daily breakthrough medication requirements 4

Common Pitfalls to Avoid

• Never apply heat to patients on fentanyl patches (fever, heating pads, electric blankets) as this accelerates absorption and can cause fatal overdose 3, 7
• Do not use fentanyl patches for unstable pain requiring frequent dose changes 3, 4
• Only use fentanyl patches in opioid-tolerant patients - a patient on buprenorphine 10 mcg/h qualifies as opioid-tolerant 4
• The significant interpatient variability with buprenorphine conversions means clinical judgment and close monitoring are essential 1