Buprenorphine and Methadone: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Buprenorphine
Methadone
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
These two are both strong opioids, but they don't mix well. Buprenorphine only partly turns on the same receptors that methadone fully turns on. Because of this, buprenorphine can actually block some of methadone's effect, which may make your pain worse or even trigger withdrawal symptoms like sweating, nausea, chills, and body aches.
At the same time, taking both can add up in dangerous ways, causing heavy drowsiness, slowed breathing, and a heart rhythm change. There is also a risk of a reaction called serotonin syndrome. Please don't start, stop, or change either medicine on your own. Your care team can manage this safely, so keep them in the loop.
Direction: Buprenorphine (partial mu agonist/antagonist) can displace/antagonize full-agonist methadone, reducing analgesia and precipitating opioid withdrawal. Concurrently, both agents produce additive CNS/respiratory depression, additive QT prolongation, and additive serotonergic effects (serotonin syndrome risk). Neither is a prodrug requiring activation; this is pharmacodynamic, not a CYP issue.
- Severity: Major; evidence probable.
- Risks: Profound sedation, respiratory depression, QTc prolongation/torsades, serotonin syndrome.
- Management: Avoid combination where possible. If unavoidable, monitor sedation, respiratory status, ECG/QTc, and serotonin toxicity, especially at initiation and methadone dose changes. Consider taper of one agent to lowest effective dose; discontinue buprenorphine if serotonin syndrome suspected.
What happens
Reduced analgesic effect or precipitation of withdrawal symptoms, an increased risk of serotonin syndrome, an increased risk of respiratory and CNS depression and an increased risk of QT interval prolongation
Interaction Deep Dive
Do not use buprenorphine together with agents capable of prolonging the QT interval, such as methadone 2. When a mixed opioid agonist/antagonist or a partial agonist opioid analgesic is given alongside methadone, the analgesic action of methadone can be diminished and withdrawal symptoms may be triggered 4. Giving buprenorphine and methadone together can produce additive CNS depression along with a heightened likelihood of serotonin syndrome, respiratory depression, deep sedation, coma, and death. Discontinuing the other CNS depressant is favored rather than using both concurrently. Depending on the situation, it may be suitable to monitor the patient at a higher level of care or to pursue a taper. In other situations, it may be suitable to gradually withdraw the patient from a CNS depressant or to reduce it to the lowest effective dose. Should combined use be required, watch for sedation, respiratory depression, and any indications of serotonin syndrome. Observe the patient closely, especially when starting therapy and while methadone doses are being adjusted. If serotonin syndrome is suspected, stop buprenorphine and think about alternative approaches for managing anxiety or insomnia 1.
Why it happens (mechanism)
Opioid receptor antagonism; additive serotonergic effects; additive CNS depression; additive QT interval prolongation
How to manage this interaction
The safest approach is usually to avoid using these two together, but this is a decision your care team makes, not something to change on your own. Keep taking both exactly as prescribed until you speak with them.
- Your prescriber may adjust doses, taper one medicine to the lowest effective dose, or choose an alternative.
- They may monitor you more closely (including your heart rhythm) especially when starting or changing methadone.
- Watch for heavy drowsiness, slowed or shallow breathing, confusion, fast heartbeat, fever, agitation, or withdrawal symptoms.
Get urgent help for trouble breathing or extreme sleepiness, and tell your pharmacist or doctor about any new anxiety or sleep medicines.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) A Swedish epidemiological study reported that patients receiving buprenorphine-based medication-assisted treatment (MAT) together with benzodiazepines or other CNS depressants (for example, drugs used to treat insomnia) have an increased risk of death. From July 1, 2005 to December 31, 2012, investigators analyzed the risk of fatal overdose, non-overdose related mortality, and all-cause mortality by comparing periods when CNS depressants were prescribed to periods without CNS depressant therapy in MAT prescribed patients (aged 18 to 50). The findings showed a raised risk of all-cause mortality (adjusted hazard ratio (HR) 1.44; 95% CI, 0.93 to 2.23) and non-overdose related mortality (HR 1.74; 95% CI 1.00 to 3.01) with MAT and benzodiazepine treatment; however, these data were not deemed statistically significant. Although the results indicated an elevated risk of fatal overdose, non-overdose mortality, and all-cause mortality during periods of coadministration of MAT and non-benzodiazepines, only the data for fatal overdose and all-cause mortality reached statistical significance; HR 2.34 (95% CI, 1.37 to 3.99) and HR 1.33 (95% CI, 1.12 to 2.45), respectively. A comparison between the benzodiazepine cohort and the non-benzodiazepine cohort was not performed because the authors did not adjust for the indication of use for the drugs 3.
Common questions
Can I take Buprenorphine and Methadone together?
Combining buprenorphine and methadone can blunt methadone's pain relief or trigger withdrawal, while also raising the risk of dangerous sedation, slowed breathing, heart rhythm problems, and serotonin syndrome. This pairing is usually avoided, so talk with your care team before changing anything. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Buprenorphine and Methadone interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Buprenorphine and Methadone interaction managed?
The safest approach is usually to avoid using these two together, but this is a decision your care team makes, not something to change on your own. Keep taking both exactly as prescribed until you speak with them. Your prescriber may adjust doses, taper one medicine to the lowest effective dose, or choose an alternative. They may monitor you more closely (including your heart rhythm) especially wh… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Buprenorphine or Methadone need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (4)
- Product Information: BRIXADI(TM) subcutaneous extended-release injection, buprenorphine subcutaneous extended-release injection. Braeburn Inc (per FDA), Plymouth Meeting, PA, 2023. DailyMed
- Product Information: BELBUCA(TM) buccal film, buprenorphine buccal film. Endo Pharmaceuticals Inc. (per FDA), Malvern, PA, 2016.
- US Food and Drug Administration (FDA): Drug Safety Communications: FDA urges caution about withholding opioid addiction medications from patients taking benzodiazepines or CNS depressants: careful medication management can reduce risks. US Food and Drug Administration (FDA). Silver Spring, MD. 2017.
- Product Information: DOLOPHINE(R) oral tablets, methadone HCl oral tablets. West-Ward Pharmaceuticals Corp. (per FDA), Eatontown, NJ, 2016. DailyMed
Keep reading about Buprenorphine
Keep reading about Methadone
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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