Ribociclib and Buprenorphine: 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
Ribociclib
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.
Let's talk about taking buprenorphine (your pain or opioid-treatment medicine) together with ribociclib (Kisqali, a cancer medicine). Ribociclib slows down the liver enzyme that clears buprenorphine, so more buprenorphine can build up in your body. That can mean stronger opioid effects, like heavy sedation and slowed breathing.
On top of that, both drugs can affect the heart's rhythm (called the QT interval), and using them together can add to that risk. The good news is your care team can manage this. They may adjust your buprenorphine dose, watch you more closely, and check your heart rhythm. Please don't change anything on your own, but do talk with your pharmacist or doctor.
Effect: Ribociclib (moderate-to-strong CYP3A4 inhibitor) reduces buprenorphine metabolism, increasing buprenorphine exposure and risk of opioid adverse events (sedation, respiratory depression). Both agents also independently prolong the QT interval, giving additive cardiac risk.
Direction: Increased buprenorphine effect. Neither is a prodrug requiring activation here.
Evidence: Probable; severity major; onset unspecified.
Management:
- Monitor ECG/QTc, especially with electrolyte disturbances.
- Consider reducing buprenorphine dose until stable; monitor for sedation and respiratory depression.
- On stopping ribociclib, anticipate reduced buprenorphine levels and possible withdrawal; dose may need upward adjustment.
- Prefer formulations allowing precise titration when adjustment is needed.
What happens
An increased risk of QT interval prolongation, increased buprenorphine exposure and an increased risk of buprenorphine-related adverse events
Interaction Deep Dive
When buprenorphine is taken together with a CYP3A4 inhibitor, buprenorphine plasma concentrations rise, which can lead to extended opioid effects such as respiratory depression. The likelihood of QT prolongation also grows when medications that influence cardiac conduction are given together. Should these agents be used concurrently, watch the patient carefully for signs of a lengthened QT interval. Reducing the buprenorphine dose until stable drug effects are reached is worth considering, along with frequent monitoring for sedation and respiratory depression. If a CYP3A4 inhibitor is stopped in a patient on buprenorphine, consider raising the buprenorphine dose until stable drug effects are attained, while watching for indications of opioid withdrawal2. Where dosing cannot be modified once the CYP3A4 inhibitor is gone, move the patient back to a buprenorphine formulation that allows finer dose titration. For patients switched from transmucosal buprenorphine given alongside CYP3A4 inhibitors, confirm through monitoring that the buprenorphine plasma level achieved with subQ buprenorphine is sufficient. In patients already receiving subQ buprenorphine who need to start a CYP3A4 inhibitor, watch for indications of over-medication. Should symptoms of buprenorphine toxicity or overdose develop while the accompanying drug cannot be lowered or stopped, decrease the buprenorphine dose. When the available doses will not allow the intended dose to be reached, stop the therapy and manage the patient with a buprenorphine formulation that permits more precise dose adjustments1.
Why it happens (mechanism)
Additive QT interval prolongation; inhibition of CYP3A4-mediated metabolism of buprenorphine
How to manage this interaction
Keep taking both medicines as prescribed unless your care team tells you otherwise. This combination is manageable with the right monitoring.
Here is what your team typically does:
- Watch your heart rhythm (QT interval), sometimes with an ECG.
- Adjust your buprenorphine dose, individualized to you, until effects are stable.
- Monitor you more closely for heavy sedation and slowed or shallow breathing.
- Re-check the dose again if ribociclib is later stopped, since buprenorphine levels may drop.
Tell your pharmacist or doctor right away if you notice extreme drowsiness, confusion, slow breathing, fainting, or a racing or irregular heartbeat.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) In a trial involving healthy volunteers (N=12), giving oral buprenorphine together with voriconazole produced a significant rise in the mean buprenorphine AUC(0 to 18 hours) of 4.3-fold (from 0.43 to 2.1 nanograms (ng) x hr/mL), a 3.9-fold increase in Cmax (from 0.057 to 0.22 ng/mL), a longer half-life (from 9.1 to 14.5 hours), and greater urinary clearance (from 0.31 to 0.73 L/hr). Voriconazole likewise significantly raised exposure to the active metabolite norbuprenorphine, by nearly 4-fold for AUC(0 to 18 hours) and 3.3-fold for Cmax, while reducing its renal clearance (from 7.2 to 2.9 L/hr). Participants reported mild dizziness and nausea during both phases. Subjects were given either placebo or voriconazole 400 mg twice daily on day 1, then 200 mg twice daily on days 2 to 5, followed by a 4-week washout before switching to the alternate regimen. On the fifth day, every subject took a single oral buprenorphine dose of 0.2 mg, or 3.6 mg during the placebo phase 3.
b) The influence of concurrently administered CYP3A4 inhibitors on buprenorphine exposure in patients receiving subQ buprenorphine has not been investigated; nevertheless, such interactions have been demonstrated in trials employing transmucosal buprenorphine. Buprenorphine's effects may vary according to the route of administration 1.
Common questions
Can I take Ribociclib and Buprenorphine together?
Ribociclib can raise buprenorphine levels and add to QT (heart rhythm) risk, so watch for excess sedation, slowed breathing, and heartbeat changes. Your care team can manage this by adjusting the buprenorphine dose and monitoring you more closely, so don't change anything on your own. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ribociclib and Buprenorphine 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 Ribociclib and Buprenorphine interaction managed?
Keep taking both medicines as prescribed unless your care team tells you otherwise. This combination is manageable with the right monitoring. Here is what your team typically does: Watch your heart rhythm (QT interval), sometimes with an ECG. Adjust your buprenorphine dose, individualized to you, until effects are stable. Monitor you more closely for heavy sedation and slowed or shallow breathing.… 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.
Questions for your pharmacist
- Does my dose of Ribociclib or Buprenorphine 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 (3)
- Product Information: BRIXADI(TM) subcutaneous extended-release injection, buprenorphine subcutaneous extended-release injection. Braeburn Inc (per FDA), Plymouth Meeting, PA, 2023. DailyMed
- Product Information: ZUBSOLV(R) sublingual tablets, buprenorphine naloxone sublingual tablets. Orexo US Inc (per FDA), Morristown, NJ, 2023. DailyMed
- Fihlman M, Hemmila T, Hagelberg NM, et al: Voriconazole greatly increases the exposure to oral buprenorphine. Eur J Clin Pharmacol 2018; 74(12):1615-1622. PubMed
Keep reading about Buprenorphine
Keep reading about Ribociclib
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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