Atazanavir and Lenacapavir Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Atazanavir
Lenacapavir 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
Increased lenacapavir exposure, increased atazanavir exposure and an increased risk of atazanavir-related adverse reaction
Interaction Deep Dive
Concomitant administration of lenacapavir with atazanavir/ritonavir or atazanavir/cobicistat is not recommended. Coadministration of lenacapavir together with atazanavir/ritonavir or atazanavir/cobicistat may result in increased exposure of lenacapavir2. Lenacapavir may increase the exposure of drugs primarily metabolized by CYP3A, initiated within 9 months after the last dose of lenacapavir 12. Coadministration of lenacapavir with atazanavir (strong CYP3A, P-gp and UGT1A1 inhibitor) may increase the exposure of atazanavir and result in the increased risk of atazanavir-related adverse events 1.
Why it happens (mechanism)
Inhibition of CYP3A-mediated metabolism of lenacapavir; inhibition of CYP3A-mediated metabolism of atazanavir; inhibition of P-gp-mediated efflux transport of lenacapavir; inhibition of UGT1A1-mediated efflux transport of lenacapavir
Literature reports
1 report — tap to read
a) In the interaction studies conducted in subjects without HIV-1, concomitant administration of single dose of lenacapavir 300 mg orally with atazanavir/cobicistat (fed) [Inhibitor of CYP3A (strong) and P-gp and UGT1A1] 350/150 mg once daily, the mean ratio for AUC and Cmax of lenacapavir were 4.21 (90% CI: 3.19 to 5.57) and 6.6 (90% CI: 4.99 to 8.73) respectively 21.
Common questions
Can I take Atazanavir and Lenacapavir Injection together?
Increased lenacapavir exposure, increased atazanavir exposure and an increased risk of atazanavir-related adverse reaction Always confirm with your pharmacist or prescriber before making any change.
How serious is the Atazanavir and Lenacapavir Injection 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 Atazanavir or Lenacapavir Injection 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: YEZTUGO(R) oral tablets, subcutaneous injection, lenacapavir oral tablets, subcutaneous injection. Gilead Sciences Inc (per manufacturer), Foster City, CA, 2025. DailyMed
- Product Information: SUNLENCA(R) oral tablets, subcutaneous injection, lenacapavir oral tablets, subcutaneous injection. Gilead Sciences Inc (per FDA), Foster City, CA, 2024. DailyMed
Keep reading about Atazanavir
Keep reading about Lenacapavir Injection
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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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