Morphine to Buprenorphine: how to convert safely
No single conversion factor exists
Buprenorphine is a partial agonist with very high receptor affinity; starting it in a patient on full agonists risks precipitated withdrawal, and the CDC 2022 guideline explicitly excludes it from MME arithmetic. There is no valid milligram conversion — the switch is a protocol, not a calculation.
How the switch is actually done
- Standard induction: allow moderate withdrawal (e.g. COWS ≥ 8–12) before the first dose, then titrate.
- Low-dose overlap ("microdosing"/Bernese): escalate tiny buprenorphine doses over ~a week while the full agonist continues, then stop the full agonist.
- Perioperative patients: current consensus favors continuing buprenorphine and layering multimodal + full-agonist analgesia, not stopping it.
- Follow your institutional protocol; involve addiction or pain medicine for induction decisions.
What this site's tools will and won't do
The opioid regimen builder totals MME for mixed regimens and flags buprenorphine lines as "specialist conversion required" rather than guessing. Use it for the rest of the regimen; use a human for this switch.
Frequently asked questions
- Why can't buprenorphine be converted with an MME factor?
- Buprenorphine is a partial mu-agonist with very high receptor affinity and a ceiling on respiratory depression. Its behavior in combination with full agonists — and the risk of precipitated withdrawal when starting it — depends on timing and the current opioid regimen, not on a milligram equivalence. The CDC's 2022 guideline explicitly excludes buprenorphine from MME math.
- How is buprenorphine actually started in a patient on full agonists?
- Either by allowing a period of withdrawal before standard induction, or by a low-dose ('microdosing'/Bernese) overlap protocol that titrates buprenorphine up over several days while the full agonist continues. Protocol choice depends on the setting and the patient — follow your institution's protocol or involve addiction/pain medicine.
- Does stopping buprenorphine before surgery make pain easier to manage?
- Current perioperative consensus has moved toward continuing buprenorphine and adding multimodal analgesia plus full agonists as needed, rather than stopping it — discontinuation risks destabilizing patients on it for opioid use disorder. Decisions should be individualized with the surgical and anesthesia teams.
Created and maintained by Yasmine Abbey, MD, MSc · Last reviewed:
Educational decision-support for clinicians. Not medical advice — verify all outputs against your clinical judgment, institutional protocols, and current guidelines.