Fluvoxamine 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
Fluvoxamine
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.
These two medicines can interact in two ways. Fluvoxamine slows down a liver enzyme (CYP3A4) that helps break down buprenorphine. When that enzyme is blocked, buprenorphine can build up in your body, which may cause more sedation, drowsiness, and in some cases slowed breathing.
On top of that, both medicines affect serotonin, a brain chemical. Using them together can raise the small chance of a condition called serotonin syndrome (things like agitation, shivering, sweating, fast heartbeat, or confusion). The good news is that your care team can manage this safely by adjusting your dose and watching you closely. Please don't stop either medicine on your own, just talk with your pharmacist or doctor.
Mechanism: Fluvoxamine is a CYP3A4 inhibitor and reduces buprenorphine metabolism, increasing buprenorphine plasma concentrations and prolonging opioid effects. Both agents are serotonergic, giving additive serotonin syndrome risk. (Buprenorphine is not a prodrug, so inhibition increases, not decreases, its effect.)
- Direction: increased buprenorphine exposure; additive serotonergic activity.
- Severity/evidence: major; probable.
- Monitor: sedation, respiratory depression, and serotonin syndrome (esp. at initiation/titration).
- Manage: consider reducing buprenorphine dose until stable; on inhibitor discontinuation, consider dose increase and watch for withdrawal. Use a formulation allowing precise titration if needed. Discontinue buprenorphine if serotonin syndrome is suspected.
What happens
An increased risk of serotonin syndrome, increased buprenorphine exposure and an increased risk of buprenorphine-related adverse events
Interaction Deep Dive
Taking buprenorphine together with CYP3A4 inhibitors can raise buprenorphine plasma levels and may result in extended opioid effects. When a patient on buprenorphine requires a CYP3A4 inhibitor, one option is to lower the buprenorphine dose until steady drug effects are reached, along with frequent monitoring for sedation and respiratory depression. Conversely, when stopping a CYP3A4 inhibitor in someone receiving buprenorphine, an increase in the buprenorphine dose may be warranted until stable effects are attained, with monitoring for signs of opioid withdrawal2. If it is not possible to adjust the dosage once the CYP3A4 inhibitor is absent, switch 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. For those already receiving subQ buprenorphine who then need a CYP3A4 inhibitor, watch for indications of over-medication. Should buprenorphine toxicity signs and symptoms appear while the co-administered drug cannot be reduced or stopped, decrease the buprenorphine dose. Furthermore, when buprenorphine must be used together with a serotonergic agent, watch the patient for signs and symptoms of serotonin syndrome, particularly at the start of therapy and when adjusting doses; if it is suspected, stop buprenorphine 1.
Why it happens (mechanism)
Additive serotonergic effects; 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 dose tailoring and closer monitoring.
- Your buprenorphine dose may need to be adjusted and individualized by your care team, and they may monitor you more closely for excess sedation or slowed breathing.
- If fluvoxamine is later stopped, your team may adjust buprenorphine again and watch for withdrawal symptoms.
- Tell your pharmacist or prescriber right away if you notice unusual drowsiness, slow or shallow breathing, or serotonin syndrome signs like agitation, shivering, sweating, fast heartbeat, or confusion.
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 levels in individuals receiving subQ buprenorphine has not been investigated; nevertheless, these interactions have been demonstrated in trials involving transmucosal buprenorphine. Buprenorphine's effects may vary according to the route of administration 1.
Common questions
Can I take Fluvoxamine and Buprenorphine together?
Fluvoxamine can raise buprenorphine levels (more sedation and breathing risk) and add to serotonin syndrome risk, so your care team may adjust your buprenorphine dose and monitor you more closely. Don't change either medicine on your own; report drowsiness, slowed breathing, or agitation/shivering promptly. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Fluvoxamine 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 Fluvoxamine and Buprenorphine interaction managed?
Keep taking both medicines as prescribed unless your care team tells you otherwise. This combination is manageable with dose tailoring and closer monitoring. Your buprenorphine dose may need to be adjusted and individualized by your care team, and they may monitor you more closely for excess sedation or slowed breathing. If fluvoxamine is later stopped, your team may adjust buprenorphine again and… 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 Fluvoxamine 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 Fluvoxamine
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