Nafcillin Injection and Bedaquiline: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Bedaquiline
Nafcillin Injection
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.
What happens
Reduced bedaquiline exposure and reduced efficacy of bedaquiline
Interaction Deep Dive
Avoid concomitant use of bedaquiline (a CYP3A4 substrate) with a moderate or strong CYP3A4 inducer as it may reduce systemic bedaquiline exposure and may reduce bedaquiline efficacy. Significant reduction in bedaquiline exposure was observed during a pharmacokinetic study of concomitant bedaquiline and rifAMPin administration1.
Why it happens (mechanism)
Induction of CYP3A4-mediated metabolism of bedaquiline
Literature reports
1 report — tap to read
a) Mean bedaquiline exposure (eg, AUC) was reduced by 52% (90% CI, -57% to -46% change) in a drug interaction study in which healthy subjects received a single dose of bedaquiline 300 mg concomitantly with the strong CYP3A4 inducer, rifAMPin, at a dose of 600 mg once daily for 21 days 1.
Common questions
Can I take Nafcillin Injection and Bedaquiline together?
Reduced bedaquiline exposure and reduced efficacy of bedaquiline Always confirm with your pharmacist or prescriber before making any change.
How serious is the Nafcillin Injection and Bedaquiline 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 strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Nafcillin Injection or Bedaquiline 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: SIRTURO(R) oral tablets, bedaquiline oral tablets. Janssen Products, LP (per FDA), Horsham, PA, 2024. DailyMed
Keep reading about Bedaquiline
Keep reading about Nafcillin Injection
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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