Buprenorphine and Pentamidine: 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
Pentamidine
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 pentamidine (used to treat or prevent certain serious infections) can affect the timing of your heartbeat. Doctors call this QT prolongation. When two medicines that do this are taken together, the effect can add up and, in rare cases, lead to a dangerous irregular heart rhythm.
The good news is this concern is based on how the drugs work, not on lots of real-world problems. Your care team can manage it. They may choose a different medicine, or watch your heart and blood minerals more closely. Please don't stop either medicine on your own. Just talk with your doctor or pharmacist about it.
Effect: Additive QT interval prolongation when buprenorphine is combined with pentamidine, a known QT-prolonging agent. Neither drug is a prodrug here; this is a pharmacodynamic (additive), not pharmacokinetic, interaction.
- Direction: Increased risk of QTc prolongation and torsades de pointes.
- Evidence: Theoretical; magnitude and onset unspecified.
- Severity: Major.
Management: Avoid concomitant use where possible. If co-administration is unavoidable, obtain baseline and follow-up ECG, and correct/monitor electrolytes. Heightened caution with hypokalemia, hypomagnesemia, bradycardia, CHF, recent AF conversion, digitalis therapy, baseline or congenital QT prolongation.
What happens
An increased risk of QT interval prolongation
Interaction Deep Dive
Buprenorphine should not be used together with medications capable of prolonging the QT interval 342. It remains unknown what risk arises from pairing buprenorphine with other agents that prolong the QT interval. When buprenorphine is prescribed 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 hypomagnesemia, these considerations should inform clinical decision making 1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
Both drugs can lengthen the QT interval, so care teams generally try to avoid using them together when a safer option exists.
- Keep taking both exactly as prescribed unless your prescriber tells you otherwise.
- Your team may choose an alternative medicine, or monitor you more closely with ECGs and blood tests for potassium and magnesium.
- Tell your doctor if you have heart rhythm problems, heart failure, or take digoxin, since these raise the risk.
- Seek urgent care for fainting, palpitations, or a racing/irregular heartbeat.
Ask your pharmacist or prescriber whether this combination is right for you.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Buprenorphine and Pentamidine together?
Buprenorphine and pentamidine can each prolong the QT interval, so combining them may raise the risk of a dangerous heart rhythm. Ask your care team whether they should be used together or if closer monitoring is needed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Buprenorphine and Pentamidine 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 Pentamidine interaction managed?
Both drugs can lengthen the QT interval, so care teams generally try to avoid using them together when a safer option exists. Keep taking both exactly as prescribed unless your prescriber tells you otherwise. Your team may choose an alternative medicine, or monitor you more closely with ECGs and blood tests for potassium and magnesium. Tell your doctor if you have heart rhythm problems, heart fail… 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 Pentamidine 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 Pentamidine
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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