Avacopan and Clindamycin: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 1, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Avacopan
Clindamycin
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.
Your two medicines can interact. Avacopan (Tavneos) slows down a liver enzyme called CYP3A4 that helps break down clindamycin. When that enzyme is slowed, clindamycin can build up in your body a bit more than usual. Higher levels can mean a greater chance of side effects, like stomach upset or diarrhea.
The good news is that this is very manageable. Your care team can keep a closer eye on how you feel and adjust your clindamycin dose if needed. Please keep taking both medicines as prescribed, and let your pharmacist or doctor know if you notice new or worsening side effects.
Mechanism: Avacopan is a moderate CYP3A4 inhibitor. Clindamycin is partially metabolized by CYP3A4 (and CYP3A5), so co-administration may reduce its clearance and increase exposure (AUC/Cmax).
Direction: Increased clindamycin exposure, raising risk of dose-related adverse effects (GI toxicity, including antibiotic-associated diarrhea/C. difficile risk).
- Evidence: Probable; magnitude not quantified.
- Onset: Unspecified.
- Management: Monitor closely for adverse reactions; consider dose reduction of the CYP3A4 substrate. Dosing should be individualized by the care team.
Neither agent's active moiety depends on CYP3A4 for activation, so exposure and effect move in the same direction.
What happens
Increased exposure to CYP3A4 substrate
Interaction Deep Dive
When avacopan, which inhibits CYP3A4, is taken together with a CYP3A4 substrate that has a narrow therapeutic index, the substrate's toxicity may be heightened; watch carefully for adverse reactions and think about lowering the dose of the CYP3A4 substrate1.
Why it happens (mechanism)
Inhibition of CYP3A4 substrate metabolism by avacopan
How to manage this interaction
This interaction is manageable with your care team's help.
- Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise.
- Your team may monitor you more closely for side effects while you are on both drugs.
- Your clindamycin dose may be adjusted and individualized by your care team if needed.
- Watch for and report side effects such as diarrhea, stomach pain, or nausea, and tell your prescriber right away about severe or persistent diarrhea.
Bring an updated list of all your medicines to your pharmacist or doctor so they can plan the safest approach.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) When simvastatin (a CYP3A4 substrate) was given together with avacopan at 60 mg daily for 7 days after food, the AUC and Cmax of simvastatin rose by 3.53-fold and 3.20-fold, respectively 1.
b) When midazolam (a CYP3A4 substrate) was given together with avacopan at 30 mg daily for 11 days on an empty stomach, the AUC and Cmax of simvastatin rose by 1.55-fold and 1.81-fold, respectively 1.
Common questions
Can I take Avacopan and Clindamycin together?
Avacopan can raise clindamycin levels by slowing its breakdown, which may increase side effects like diarrhea. Keep taking both as prescribed and ask your care team about closer monitoring or a possible dose adjustment. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Avacopan and Clindamycin 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 Avacopan and Clindamycin interaction managed?
This interaction is manageable with your care team's help. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise. Your team may monitor you more closely for side effects while you are on both drugs. Your clindamycin dose may be adjusted and individualized by your care team if needed. Watch for and report side effects such as diarrhea, stomach pain, or nausea,… 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.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Avacopan or Clindamycin 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 (1)
- Product Information: TAVNEOS(R) oral capsules, avacopan oral capsules. ChemoCentryx Inc (per FDA), Thousand Oaks, CA, 2024. DailyMed
Keep reading about Avacopan
Keep reading about Clindamycin
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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