Buprenorphine and Iloperidone: 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
Iloperidone
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 and iloperidone (Fanapt) can affect the timing of your heartbeat. Each one can slightly stretch out a part of the heart's electrical cycle called the QT interval. When you take them together, that effect can add up, which in rare cases could lead to an irregular heartbeat.
I want to be honest with you: this concern is mostly theoretical, meaning it is based on how the drugs work rather than lots of real-world reports. The good news is your care team can manage this easily by keeping an eye on things. Please don't stop either medicine on your own. Just talk with your doctor or pharmacist so they can decide what's best for you.
Effect: Additive risk of QT interval prolongation with concurrent buprenorphine and iloperidone. Neither is a prodrug relevant here; this is a pharmacodynamic (additive), not pharmacokinetic, interaction.
Direction/magnitude: Both agents independently prolong QTc; combined use compounds repolarization delay. Magnitude with the pair is not quantified.
Evidence: Theoretical. Onset: Unspecified.
Management:
- Manufacturer labeling advises avoiding concomitant QT-prolonging drugs with buprenorphine.
- If co-prescribed, obtain baseline and follow-up ECG and monitor QTc.
- Correct electrolytes (K+, Mg2+); heightened caution with bradycardia, CHF, digitalis, baseline or congenital long-QT.
What happens
An increased risk of QT interval prolongation
Interaction Deep Dive
The simultaneous administration of buprenorphine alongside agents capable of prolonging the QT interval should be avoided 342. It remains unknown what risk arises from pairing buprenorphine with additional QT prolongation agents. When prescribing buprenorphine to patients presenting with 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 observations warrant consideration in clinical decision-making 1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
Your care team can manage this safely. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise.
- Your doctor may check an ECG (heart tracing) before and during treatment to watch your QT interval.
- They may check and correct potassium and magnesium levels, since low levels raise the risk.
- Extra caution applies if you have a slow heart rate, heart failure, or a known long-QT condition.
- Tell your prescriber if you feel fainting, dizziness, or a fluttering or irregular heartbeat.
Bring this up with your pharmacist or doctor so they can decide the best approach for you, which may include monitoring or choosing an alternative.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Buprenorphine and Iloperidone together?
Combining buprenorphine and iloperidone can add up to prolong the QT interval, so your care team may monitor your heart rhythm and electrolytes or consider an alternative. Keep taking both as prescribed and report any fainting or irregular heartbeat. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Buprenorphine and Iloperidone 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 Iloperidone interaction managed?
Your care team can manage this safely. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise. Your doctor may check an ECG (heart tracing) before and during treatment to watch your QT interval. They may check and correct potassium and magnesium levels, since low levels raise the risk. Extra caution applies if you have a slow heart rate, heart failure, or a kno… 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 Iloperidone 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 Iloperidone
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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