Suzetrigine and Lenacapavir Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Lenacapavir Injection
Suzetrigine
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 suzetrigine and M6-SUZ (active metabolite) exposure and an increased risk of suzetrigine-related adverse reactions
Interaction Deep Dive
Concomitant use of suzetrigine (CYP3A substrates) with moderate CYP3A inhibitors may increase suzetrigine and M6-SUZ exposures, which may cause adverse reactions. When suzetrigine is administered to patients taking moderate CYP3A inhibitors reduce the suzetrigine dose, as described below: Dose 1: The recommended starting dose of suzetrigine is 100 mg orally. Take the starting dose on an empty stomach at least 1 hour before or 2 hours after food. Clear liquids may be consumed during this time (eg., water, apple juice, vegetable broth, tea, black coffee). Doses 2, 3, and 4: Starting 12 hours after the initial dose, take 50 mg of suzetrigine orally every 12 hours. Take these doses with or without food. Dose 5 and subsequent doses: Starting 12 hours after dose 4, take 50 mg of suzetrigine orally every 24 hours. Take these dose(s) with or without food. In a drug interaction study, concomitant use of fluconazole (a moderate CYP3A inhibitor) with suzetrigine with the recommended dosage modification is predicted to increase the geometric mean (CI 90%) AUC tau of suzetrigine and M6-SUZ by 1.5-fold (1.4-1.5) and 1.2-fold (1.2-1.3), respectively, while the geometric mean (CI 90%) Cmax of suzetrigine and M6-SUZ is predicted to increase by 1.4-fold (1.4-1.5) and 1.1-fold (1.1-1.2), respectively, when compared to the regular recommended dosage in the absence of fluconazole1.
Why it happens (mechanism)
Inhibition of CYP3A-mediated metabolism of suzetrigine
Literature reports
1 report — tap to read
a) In a drug interaction study, concomitant use of fluconazole (a moderate CYP3A inhibitor) with suzetrigine with the recommended dosage modification is predicted to increase the geometric mean (CI 90%) AUC tau of suzetrigine and M6-SUZ by 1.5-fold (1.4-1.5) and 1.2-fold (1.2-1.3), respectively, while the geometric mean (CI 90%) Cmax of suzetrigine and M6-SUZ is predicted to increase by 1.4-fold (1.4-1.5) and 1.1-fold (1.1-1.2), respectively, when compared to the regular recommended dosage in the absence of fluconazole 1.
Common questions
Can I take Suzetrigine and Lenacapavir Injection together?
Increased suzetrigine and M6-SUZ (active metabolite) exposure and an increased risk of suzetrigine-related adverse reactions Always confirm with your pharmacist or prescriber before making any change.
How serious is the Suzetrigine 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 "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Suzetrigine 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 (1)
- Product Information: JOURNAVX oral tablets, suzetrigine oral tablets. Vertex Pharmaceuticals Inc (per FDA), Boston, MA, 2025. DailyMed
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