Repotrectinib 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
Clindamycin
Repotrectinib
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.
Here's what's going on with these two medicines. Repotrectinib (Augtyro) speeds up an enzyme in your body called CYP3A4, which is the same system that helps break down clindamycin. When that enzyme works faster, your body clears clindamycin more quickly, so the antibiotic level in your blood can drop. That means clindamycin may not fight your infection as well as it should.
The good news is your care team can manage this. Don't stop or change either medicine on your own. Just let your pharmacist or doctor know you're taking both, so they can adjust your treatment and keep a close eye on how you're doing.
Effect: Repotrectinib is a CYP3A4 inducer; clindamycin is a CYP3A4 substrate. Concurrent use increases clindamycin metabolism, lowering its exposure (AUC/Cmax) and potentially reducing antibacterial efficacy.
Magnitude: Reference substrate midazolam showed AUC decreased ~69% and Cmax ~48% with repotrectinib 160 mg. Evidence: probable. Onset: unspecified (induction typically develops over days).
- Avoid combination where a narrow-therapeutic-index substrate is involved.
- If unavoidable, the substrate dose may need to be increased and individualized.
- Monitor clinical response to clindamycin (signs of inadequate treatment).
What happens
Reduced CYP3A4 substrates exposure and reduced efficacy of CYP3A4 substrates
Interaction Deep Dive
Repotrectinib acts as an inducer of CYP3A4, so its combined use with CYP3A4 substrates that have a narrow therapeutic index should be avoided. When taken together, repotrectinib lowers the exposure of CYP3A4 substrates, and even small changes in concentration may result in diminished efficacy. Should combined use be necessary, raise the dose of the CYP3A4 substrate as needed. In drug interaction studies, the AUC (0 to inf) of midazolam (a CYP3A4 substrate) fell by 69% and its Cmax by 48% when co-administered in subjects who had been given 160 mg repotrectinib once daily for 14 days and then 160 mg twice daily for 7 days1.
Why it happens (mechanism)
Induction of CYP3A4-substrate metabolism by repotrectinib
How to manage this interaction
Your care team has clear ways to handle this combination:
- They may adjust your clindamycin dose. Because repotrectinib can lower clindamycin levels, the dose may need to be increased and individualized so the antibiotic still works.
- They may monitor you more closely to make sure your infection is responding.
- They may consider an alternative if a suitable option fits your situation.
What you should do: keep taking both exactly as prescribed, and tell your pharmacist or prescriber that you're on both drugs. Report any signs your infection isn't improving.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In the drug interaction studies, the AUC (0 to inf) of midazolam (a CYP3A4 substrate) fell by 69% and its Cmax by 48% with concurrent administration in subjects who had previously received 160 mg repotrectinib once daily for 14 days followed by 160 mg twice daily for 7 days 1.
Common questions
Can I take Repotrectinib and Clindamycin together?
Repotrectinib can speed up the breakdown of clindamycin, lowering its levels and possibly weakening the antibiotic's effect. Keep taking both as prescribed and ask your pharmacist or doctor, who can adjust the dose or monitor you. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Repotrectinib 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 Repotrectinib and Clindamycin interaction managed?
Your care team has clear ways to handle this combination: They may adjust your clindamycin dose. Because repotrectinib can lower clindamycin levels, the dose may need to be increased and individualized so the antibiotic still works. They may monitor you more closely to make sure your infection is responding. They may consider an alternative if a suitable option fits your situation. What you should… 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 Repotrectinib 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: AUGTYRO(TM) oral capsules, repotrectinib oral capsules. Bristol-Myers Squibb Company (per FDA), Princeton, NJ, 2023. DailyMed
Keep reading about Clindamycin
Keep reading about Repotrectinib
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