Maraviroc and Efavirenz: 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 recordMaraviroc
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
Decreased maraviroc plasma concentrations and exposure (AUC)
Interaction Deep Dive
When maraviroc was coadministered with efavirenz, the maraviroc AUC decreased 45%. The concomitant use of maraviroc (a CYP3A substrate) with efavirenz (a CYP3A inducer) is contraindicated in adult and pediatric patients with CrCl less than 30 mL/min and in those with ESRD on regular hemodialysis. In adults with CrCl 30 mL/min or greater treated with maraviroc and efavirenz (and no strong CYP3A inhibitors), increase the maraviroc dose to 600 mg orally twice daily. In pediatric patients with CrCl 30 mL/min or greater, concomitant use of maraviroc and efavirenz is not recommended1.
Why it happens (mechanism)
Induction of CYP3A4-mediated maraviroc metabolism
Literature reports
1 report — tap to read
a) Concomitant administration of efavirenz and maraviroc resulted in decreased maraviroc area-under-the-time-curve (AUC) and plasma concentrations. When efavirenz 600 mg once daily was administered concurrently with maraviroc 100 mg twice daily in 12 patients, the ratio of maraviroc pharmacokinetic parameters with efavirenz to without efavirenz was: Cmin 0.55 (90% confidence interval (CI), 0.43-0.72), AUC 0.55 (90% CI, 0.49-0.62), and Cmax 0.49 (90% CI, 0.38-0.63) 1.
Common questions
Can I take Maraviroc and Efavirenz together?
Decreased maraviroc plasma concentrations and exposure (AUC) Always confirm with your pharmacist or prescriber before making any change.
How serious is the Maraviroc and Efavirenz interaction?
It is rated contraindicated. These should generally not be used together.
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 "established". Well documented — supported by controlled studies or strong clinical data.
Questions for your pharmacist
- Does my dose of Maraviroc or Efavirenz 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: SELZENTRY(R) oral tablets, oral solution, maraviroc oral tablets, oral solution. Viiv Healthcare (per FDA), Research Triangle Park, NC, 2018. DailyMed
Keep reading about Efavirenz
Keep reading about Maraviroc
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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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