Cobicistat 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
Cobicistat
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.
Cobicistat can make buprenorphine build up in your body. Cobicistat is a strong "booster" drug that slows down a liver enzyme (called CYP3A4) that normally breaks down buprenorphine. When that enzyme is blocked, more buprenorphine stays in your system for longer.
That means the usual opioid effects can become stronger, like feeling very sleepy, dizzy, or in serious cases, slowed or shallow breathing. The good news is that your care team can manage this. Please don't stop or change either medicine on your own. Talk with your pharmacist or doctor so they can adjust your buprenorphine dose if needed and keep a closer eye on you.
Mechanism: Cobicistat is a potent CYP3A4 inhibitor; buprenorphine is a CYP3A4 substrate. Inhibition reduces buprenorphine metabolism, increasing plasma exposure (AUC/Cmax) and raising risk of dose-related opioid toxicity.
- Direction: Increased buprenorphine effect (sedation, respiratory depression).
- Severity/evidence: Major; probable.
- Management: If cobicistat is started, consider reducing buprenorphine dose until stable and monitor closely for sedation/respiratory depression. On cobicistat discontinuation, anticipate a dose increase and watch for withdrawal. For long-acting subQ depot formulations, monitor for over-medication; use formulations allowing precise titration if adjustment is needed.
What happens
Increased buprenorphine exposure and an increased risk of buprenorphine-related adverse events
Interaction Deep Dive
Because a CYP3A4 inhibitor raises plasma levels of buprenorphine, taking the two together can extend opioid effects such as respiratory depression. When a CYP3A4 inhibitor must be given to someone already on buprenorphine, it may be appropriate to lower the buprenorphine dose until drug effects stabilize, with frequent checks for sedation and respiratory depression. Conversely, when a CYP3A4 inhibitor is being stopped in a patient on buprenorphine, it may be appropriate to raise the buprenorphine dose until stable drug effects are reached, watching for indications of opioid withdrawal2. Should dose adjustment prove impossible 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 that the plasma buprenorphine level achieved by subQ buprenorphine is sufficient. For patients already receiving subQ buprenorphine who then need a CYP3A4 inhibitor, watch for indications of over-medication. If buprenorphine toxicity or overdose appears yet the co-administered drug can neither be lowered nor stopped, decrease the buprenorphine dose. When the available doses cannot deliver the intended dose, stop treatment and manage the patient with a buprenorphine formulation that permits more precise dose adjustments 1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of buprenorphine
How to manage this interaction
Keep taking both exactly as prescribed unless your care team tells you otherwise. This combination is usually manageable with the right adjustments.
- Your team may lower your buprenorphine dose while you are on cobicistat, and adjust it back up if cobicistat is stopped. Your dose may need to be individualized by your care team.
- They may monitor you more closely for sedation, slowed breathing, or (when cobicistat stops) signs of opioid withdrawal.
- If you are on a long-acting buprenorphine (like an injection or patch), your team may switch you to a form that allows more precise dosing.
Call your prescriber or pharmacist right away if you feel unusually drowsy, confused, or have trouble breathing.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) The impact of concurrently administered CYP3A4 inhibitors on buprenorphine exposure in patients receiving subQ buprenorphine has not been evaluated; nevertheless, interactions of this kind have been demonstrated in studies involving transmucosal buprenorphine. The effects of buprenorphine may vary according to the route of administration 1.
Common questions
Can I take Cobicistat and Buprenorphine together?
Cobicistat blocks the enzyme that clears buprenorphine, so buprenorphine levels rise and opioid side effects like sedation and slowed breathing become more likely. Your care team can manage this by adjusting your dose and monitoring you closely, so keep both medicines as prescribed and report any excessive drowsiness or breathing problems. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Cobicistat 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 Cobicistat and Buprenorphine interaction managed?
Keep taking both exactly as prescribed unless your care team tells you otherwise. This combination is usually manageable with the right adjustments. Your team may lower your buprenorphine dose while you are on cobicistat, and adjust it back up if cobicistat is stopped. Your dose may need to be individualized by your care team. They may monitor you more closely for sedation, slowed breathing, or (w… 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 Cobicistat 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 (2)
- 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
Keep reading about Buprenorphine
Keep reading about Cobicistat
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.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist