What is the conversion rate from Butrans (buprenorphine) to fentanyl for a hospice patient?

Converting Butrans (Buprenorphine) to Fentanyl Patch in Hospice Patients

For hospice patients converting from Butrans (buprenorphine) to fentanyl patch, use a 1:80 conversion ratio (buprenorphine mcg/hr to fentanyl mcg/hr), which is more accurate than the traditional 1:100 ratio in elderly hospice populations. 1

Conversion Algorithm

Step 1: Calculate Current Buprenorphine Dose

• Identify the current Butrans patch strength in mcg/hr 1
• Note: Butrans patches come in 5,10,15, and 20 mcg/hr strengths

Step 2: Apply the 1:80 Conversion Ratio

• Divide the buprenorphine dose by 80 to determine the equivalent fentanyl patch dose 1
• Example: A patient on Butrans 20 mcg/hr would convert to fentanyl 25 mcg/hr (20 ÷ 80 = 0.25, rounded to nearest available patch strength)
• This 1:80 ratio is specifically validated in elderly hospice patients and appears more accurate than the traditional 1:100 ratio 1

Step 3: Reduce for Incomplete Cross-Tolerance

• Reduce the calculated fentanyl dose by 25-50% to account for incomplete cross-tolerance and patient variability 2
• This reduction is critical when converting between different opioids 2

Step 4: Patch Application Timing

• Apply the fentanyl patch and continue the Butrans patch for 12-24 hours, as fentanyl levels take 12-16 hours to reach therapeutic levels 3
• Remove the Butrans patch after 12-24 hours once fentanyl absorption is established 3

Critical Considerations for Hospice Patients

Cachectic Patients

• Anticipate the need for 25-50% higher fentanyl patch doses in cachectic hospice patients due to impaired absorption 4
• Monitor closely at 48-72 hours and consider more frequent patch changes (every 48 hours instead of 72 hours) if pain control wanes 4

Breakthrough Medication

• Prescribe immediate-release opioid breakthrough medication, particularly during the first 8-24 hours after fentanyl patch application 4
• Fentanyl levels continue rising during this initial period, requiring available rescue medication 4

Safety Precautions

• Fentanyl patches should only be used in opioid-tolerant patients (patients already on Butrans qualify) 4
• Heat application is absolutely contraindicated as it accelerates absorption and can cause fatal overdose 4

Monitoring and Titration

• Reassess pain control at 48-72 hours after conversion 4
• Use clinical judgment for dose titration, as patient variability requires individualized approaches 4
• No difference in survival has been demonstrated between transdermal fentanyl and buprenorphine in elderly hospice populations 1

Common Pitfall to Avoid

The most significant error is using the traditional 1:100 buprenorphine-to-fentanyl conversion ratio, which results in underdosing in elderly hospice patients. The 1:80 ratio provides more accurate equianalgesia in this specific population 1, though you must still reduce by 25-50% for cross-tolerance 2.