Morphine Equivalent of 1 mg Buprenorphine Daily
1 mg of oral buprenorphine per day is equivalent to approximately 75 mg of oral morphine per day. 1
Conversion Factor
Oral buprenorphine has a relative effectiveness of 75 compared to oral morphine (where morphine = 1), meaning buprenorphine is 75 times more potent than oral morphine on a milligram-per-milligram basis. 1
To calculate the morphine equivalent: multiply the buprenorphine dose by 75. 1
- 1 mg buprenorphine × 75 = 75 mg morphine equivalent daily dose (MEDD)
Route-Specific Considerations
The conversion factor varies significantly by route of administration:
- Oral buprenorphine: 75× more potent than oral morphine 1
- Intravenous buprenorphine: 100× more potent than oral morphine 1
- Transdermal buprenorphine: Uses a factor of 4 (similar to fentanyl patches), but this is calculated differently based on mcg/hour rather than total daily mg 1
Critical Caveats
The CDC 2022 guidelines explicitly exclude buprenorphine products approved for pain from their standard morphine milligram equivalent (MME) conversion table because of buprenorphine's partial μ-receptor agonist activity and resultant ceiling effects compared with full μ-receptor agonists. 1
This partial agonist property means buprenorphine has a ceiling effect for respiratory depression, making it pharmacologically different from full opioid agonists like morphine. 1
Equianalgesic conversions are only estimates and cannot account for individual variability in genetics and pharmacokinetics. 1
When converting between opioids, the calculated MME dose should not be used directly to determine the new opioid dose; the new opioid should typically be dosed at a substantially lower dose (25-50% reduction) than the calculated MME to avoid overdose due to incomplete cross-tolerance. 1, 2
Clinical Context
The 1:75 conversion ratio is derived from European Society for Medical Oncology (ESMO) guidelines for cancer pain management, where this conversion has been validated in clinical practice. 1
Buprenorphine has specific advantages in patients with renal impairment where dose reduction is not necessary, as it is mainly metabolized hepatically to norbuprenorphine (a metabolite 40 times less potent than the parent compound). 1
The maximal daily dose for oral buprenorphine is 4 mg, which would equate to approximately 300 mg MEDD. 1