Buprenorphine and Mizolastine: 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
Mizolastine
No brand names on record
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 of these medicines can affect your heart's rhythm. Buprenorphine (a pain or addiction medicine) and mizolastine (an antihistamine for allergies) can each slightly stretch out a part of your heartbeat called the QT interval. When you take them together, that effect can add up, which in rare cases can lead to an irregular heartbeat.
This concern is based on how the drugs work rather than lots of real-world reports, so try not to worry. The risk is higher if you have a heart condition, low potassium or magnesium, or a slow heart rate. Please talk with your pharmacist or doctor about the best plan for you. Your care team can manage this safely.
Interaction: Additive QT interval prolongation with concurrent buprenorphine and mizolastine.
- Mechanism: Pharmacodynamic additive effect on cardiac repolarization; both agents independently prolong the QT interval. Neither is a prodrug, so effect is direct.
- Direction: Increased combined QT-prolonging effect and torsades de pointes risk.
- Evidence: Theoretical; magnitude and onset not established.
- Management: Avoid concomitant use where feasible. If combined, correct electrolytes (K+, Mg2+), review other QT-prolonging agents, and consider ECG monitoring. Exercise heightened caution in bradycardia, CHF, digitalis therapy, baseline QT prolongation, or congenital long-QT syndrome.
What happens
An increased risk of QT interval prolongation
Interaction Deep Dive
Do not use buprenorphine together with medications that have the potential to prolong the QT interval342. What happens when buprenorphine is paired with other agents that prolong QT prolongation remains unknown. Take these points into account when making clinical decisions about prescribing buprenorphine to patients who have risk factors, including hypokalemia, bradycardia, recent conversion from atrial fibrillation, congestive heart failure, digitalis therapy, baseline QT prolongation, subclinical long-QT syndrome, or severe hypomagnesemia1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
What your care team may do:
- Prefer avoiding this combination when a safer alternative exists.
- Check and correct potassium and magnesium levels if needed.
- Watch more closely (including possible ECG checks) if you have heart risk factors, a slow heart rate, heart failure, or a known QT problem.
What you should do: Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise. Tell your pharmacist or doctor about all your medicines, and report symptoms like fainting, palpitations, or dizziness right away so your team can tailor and monitor your treatment.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Buprenorphine and Mizolastine together?
Buprenorphine and mizolastine can each prolong the QT interval, and together that risk may add up, so your care team may avoid the combination or monitor you closely, especially if you have heart risk factors. Never stop or change either medicine on your own; talk with your pharmacist or doctor first. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Buprenorphine and Mizolastine 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 Mizolastine interaction managed?
What your care team may do: Prefer avoiding this combination when a safer alternative exists. Check and correct potassium and magnesium levels if needed. Watch more closely (including possible ECG checks) if you have heart risk factors, a slow heart rate, heart failure, or a known QT problem. What you should do: Keep taking both medicines exactly as prescribed unless your prescriber tells you othe… 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 Mizolastine 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 Mizolastine
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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