Clindamycin and Apalutamide: 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
Apalutamide
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.
You've been prescribed apalutamide (Erleada) along with the antibiotic clindamycin. Here's the thing: apalutamide speeds up an enzyme in your body called CYP3A4, and that enzyme helps break down clindamycin. When clindamycin gets cleared out faster than normal, there may be less of it in your body to fight the infection. That could mean the antibiotic doesn't work as well as it should.
The good news is your care team can manage this. They may choose a different antibiotic that isn't affected, or they may watch you closely to make sure your infection is clearing. Please don't stop either medicine on your own. Just talk with your pharmacist or doctor.
Effect: Apalutamide is a strong CYP3A4 inducer. Clindamycin is partially metabolized by CYP3A4, so coadministration may reduce clindamycin exposure (lower AUC/Cmax) via induced hepatic and intestinal metabolism.
Direction: Reduced clindamycin effect, risking subtherapeutic antibiotic levels and possible treatment failure.
- Onset: Unspecified; enzyme induction is typically delayed (days to weeks) and persists after stopping apalutamide.
- Evidence: Probable.
- Management: Prefer an antibiotic not primarily CYP3A4-dependent. If coadministration is required, monitor closely for loss of clinical efficacy and clinical failure of the infection.
What happens
Reduced CYP3A4 substrate exposure
Interaction Deep Dive
When apalutamide is taken together with substrates of CYP3A4, exposure to those substrates may be lowered. Study data showed that giving apalutamide alongside midazolam (a CYP3A4 substrate) led to a reduction in apalutamide exposure. During treatment with apalutamide, it is advisable to switch any drug that relies chiefly on CYP3A4 for its metabolism to an alternative. Should concurrent administration be unavoidable, monitor the patient for any decline in the substrate's activity1.
Why it happens (mechanism)
Induction of CYP3A4-mediated metabolism by apalutamide
How to manage this interaction
Keep taking both medicines exactly as prescribed unless your care team tells you otherwise. Because apalutamide can make clindamycin clear faster, your prescriber may:
- Choose a different antibiotic that apalutamide doesn't affect.
- If clindamycin is needed, monitor you more closely to be sure the infection is responding.
What to do: tell your pharmacist and prescriber that you take apalutamide before starting any new antibiotic. Let them know right away if your infection isn't improving, gets worse, or comes back, since that could signal the antibiotic isn't working well enough.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) When a single dose of apalutamide was given together with midazolam, a CYP3A4 substrate, the midazolam AUC fell by 92% 1.
Common questions
Can I take Clindamycin and Apalutamide together?
Apalutamide can speed up the breakdown of clindamycin, which may make the antibiotic less effective. Your care team may switch to a different antibiotic or watch your infection closely, so tell them you take apalutamide. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Clindamycin and Apalutamide 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 Clindamycin and Apalutamide interaction managed?
Keep taking both medicines exactly as prescribed unless your care team tells you otherwise. Because apalutamide can make clindamycin clear faster, your prescriber may: Choose a different antibiotic that apalutamide doesn't affect. If clindamycin is needed, monitor you more closely to be sure the infection is responding. What to do: tell your pharmacist and prescriber that you take apalutamide befo… 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 Clindamycin or Apalutamide 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: ERLEADA(R) oral tablets, apalutamide oral tablets. Janssen Products LP (per FDA), Horsham, PA, 2024. DailyMed
Keep reading about Apalutamide
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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