Buprenorphine and Formoterol: 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
Formoterol
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.
Both buprenorphine (a pain and addiction medicine) and formoterol (an inhaler that opens your airways) can each affect your heart's electrical timing, something called the QT interval. When two medicines that do this are used together, they can add up and slightly raise the chance of an unusual or fast heartbeat.
I want to be honest with you: this concern is mostly theoretical, meaning we don't have strong proof it happens often with these two together. Still, it's worth respecting. Please don't stop either medicine on your own. Just talk with your pharmacist or doctor so they can look at your heart health and keep an eye on things.
Effect: Additive risk of QT-interval prolongation with concurrent buprenorphine and formoterol.
Mechanism: Both agents can prolong the QT interval; the interaction is pharmacodynamic (additive), not metabolic. Neither is a prodrug relevant here.
- Direction/magnitude: Combined effect may exceed either alone; actual magnitude unknown.
- Onset: Unspecified.
- Evidence: Theoretical.
- Management: Avoid concomitant use where feasible. Assess/correct risk factors (hypokalemia, hypomagnesemia, bradycardia, CHF, baseline or congenital QT prolongation, recent AF cardioversion, digitalis therapy). Consider ECG and electrolyte monitoring if co-prescribed.
What happens
An increased risk of QT interval prolongation
Interaction Deep Dive
Do not use buprenorphine together with medications that can lengthen the QT interval342. It remains unknown what risk arises from pairing buprenorphine with additional QT-prolonging agents. When prescribing buprenorphine to individuals who have risk factors, these considerations should inform clinical judgment. Such risk factors include hypokalemia, bradycardia, recent cardioversion from atrial fibrillation, congestive heart failure, treatment with digitalis, preexisting QT prolongation, subclinical long-QT syndrome, or severe hypomagnesemia 1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
The main strategy your care team may use is to avoid using these two together when a good alternative exists, since the combined effect on heart rhythm isn't fully quantified.
- Keep taking both exactly as prescribed unless your prescriber tells you otherwise.
- Your team may check your potassium and magnesium levels and possibly order an ECG, especially if you have heart disease, a slow heartbeat, or a known QT problem.
- Tell your pharmacist or doctor about any fainting, dizziness, or a fluttering/pounding heartbeat right away.
Share your full medication and health history so your team can tailor the safest plan for you.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Buprenorphine and Formoterol together?
Buprenorphine and formoterol can each affect your heart's rhythm (QT interval), so using them together may add up; the risk is theoretical, but let your pharmacist or doctor review it, especially if you have heart concerns. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Buprenorphine and Formoterol 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 Formoterol interaction managed?
The main strategy your care team may use is to avoid using these two together when a good alternative exists, since the combined effect on heart rhythm isn't fully quantified. Keep taking both exactly as prescribed unless your prescriber tells you otherwise. Your team may check your potassium and magnesium levels and possibly order an ECG, especially if you have heart disease, a slow heartbeat, or… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Buprenorphine or Formoterol 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: BUTRANS(R) transdermal system patch, buprenorphine transdermal system patch. Purdue Pharma L.P. (per FDA), Stamford, CT, 2016. DailyMed
- Product Information: BELBUCA(TM) buccal film, buprenorphine buccal film. Endo Pharmaceuticals Inc. (per FDA), Malvern, PA, 2016.
- Product Information: BUPRENEX(R) intravenous injection, intramuscular injection, buprenorphine HCl intravenous injection, intramuscular injection. Indivior Inc. (per DailyMed), Richmond, VA, 2016. DailyMed
Keep reading about Buprenorphine
Keep reading about Formoterol
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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