Efavirenz and Bedaquiline: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Efavirenz
No brand names on recordBedaquiline
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 an increased risk of QT interval prolongation
Interaction Deep Dive
Avoid concomitant use of bedaquiline and efavirenz as this may decrease bedaquiline exposure and may reduce bedaquiline efficacy. During drug interaction studies, coadministration of bedaquiline (a CYP3A4 substrate) and efavirenz (a moderate CYP3A4 inducer) resulted in a 20% decrease in bedaquiline exposure1. Also, consider alternatives to efavirenz when used concomitantly with another drug that prolongs the QT interval, such as bedaquiline, because additive effects on the QT interval may also occur 2. Monitor ECG before initiation of treatment, 2 weeks after initiation and during treatment. Obtain electrolytes at baseline and during treatment and correct electrolytes. Discontinue bedaquiline if there is evidence of serious ventricular arrhythmia or QTc interval greater than 500 ms 1.
Why it happens (mechanism)
Induction of CYP3A4-mediated bedaquiline metabolism by efavirenz; additive QT interval prolongation
Literature reports
2 reports — tap to read
a) During drug interaction studies in healthy volunteers, coadministration of a single dose of bedaquiline 400 mg and efavirenz 600 mg/day for 27 days resulted in a 20% decrease in bedaquiline AUC. Alteration in the Cmax of bedaquiline were not reported. Increases in both AUC and Cmax were reported in the primary metabolite of bedaquiline (70% and 80%, respectively) 1.
b) In a study, where bedaquiline was administered with the QTc prolonging drugs clofazimine and levoFLOXacin, 5% of patients in the 40-week bedaquiline treatment group experienced a QTc 500 ms or greater and 43% of patients experienced an increase in QTc 60 ms or greater over baseline. Of the clofazimine-and levoFLOXacin-treated patients in the 40-week control arm, 7% of patients experienced a QTc 500 ms or greater and 39% experienced an increase in QTc 60 ms or greater over baseline 1.
Common questions
Can I take Efavirenz and Bedaquiline together?
Reduced bedaquiline exposure and an increased risk of QT interval prolongation Always confirm with your pharmacist or prescriber before making any change.
How serious is the Efavirenz 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 "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Efavirenz 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 (2)
- Product Information: SIRTURO(R) oral tablets, bedaquiline oral tablets. Janssen Products, LP (per FDA), Horsham, PA, 2024. DailyMed
- Product Information: SUSTIVA(R) oral capsules, oral tablets, efavirenz oral capsules, oral tablets. Bristol-Myers Squibb Company (per FDA), Princeton, NJ, 2023. DailyMed
Keep reading about Efavirenz
Keep reading about Bedaquiline
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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