Sertraline and Ensitrelvir: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Sertraline
No brand names on recordEnsitrelvir
No brand names on record
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.
Ensitrelvir is an antiviral that strongly blocks a liver enzyme called CYP3A, which your body uses to break down many other medicines. Sertraline (an antidepressant) is partly cleared by this same pathway. When you take both, sertraline can build up in your body, which may increase side effects like nausea, sleepiness, jitteriness, or effects on your heart rhythm.
Because of how powerfully ensitrelvir blocks this enzyme, this combination is flagged as one to avoid. The good news is your care team knows how to handle this. Please don't change anything on your own. Talk with your pharmacist or doctor so they can decide on the safest timing or an alternative.
Mechanism: Ensitrelvir is a potent CYP3A inhibitor; sertraline is a partial CYP3A substrate (also metabolized via CYP2C19/2B6/2D6). Inhibition reduces sertraline clearance, increasing exposure.
Direction/magnitude: Increased sertraline AUC/Cmax expected. Probe data show midazolam AUC increased ~6.8-fold and dexamethasone AUC ~3.5-fold with ensitrelvir; effect on sertraline is a class extrapolation.
- Onset: unspecified; inhibition persists days after last ensitrelvir dose (dexamethasone still elevated at day 10).
- Evidence: probable; labeling classifies coadministration as contraindicated.
- Management: Evaluate PK factors before initiating ensitrelvir; reinitiate the substrate based on duration of CYP3A inhibition. Monitor for serotonergic and QT-related adverse effects.
What happens
Increased CYP3A substrates exposure and an increased risk of CYP3A substrates-related adverse effects
Interaction Deep Dive
Giving ensitrelvir together with CYP3A substrates is contraindicated because doing so can raise the exposure of those substrates and lead to adverse effects. In one drug interaction study, when a single 2 mg oral dose of midazolam (a CYP3A substrate) was given alongside ensitrelvir at the clinical dose (375 mg on day 1 followed by 125 mg on days 2 through 5) on Day 5, midazolam Cmax rose roughly 2.80-fold and its AUC(0 to inf) rose 6.77-fold relative to midazolam given by itself. Similarly, a single 1 mg dose of dexAMETHasone administered with ensitrelvir (750 mg on day 1 and 250 mg on days 2 through 5, which is twice the recommended dose) on day 5, and administered alone on day 9 (5 days after the final ensitrelvir dose) and on day 14 (10 days after the final ensitrelvir dose), produced an approximately 1.47-fold rise in Cmax and a 3.47-fold rise in AUC(0 to inf) of dexAMETHasone on day 5, a 1.24-fold rise in Cmax and a 2.38-fold rise in AUC(0 to inf) on day 9, and a 1.17-fold rise in Cmax and a 1.58-fold rise in AUC(0 to inf) on day 14, each compared with dexAMETHasone given alone. Ensitrelvir should be started only after the relevant clinical and pharmacokinetic factors tied to the concomitant medication have been carefully weighed. Furthermore, reinitiating contraindicated CYP3A substrates should be considered based on an evaluation of how long CYP3A inhibition lasts along with patient specific considerations1.
Why it happens (mechanism)
Inhibition of CYP3A-mediated metabolism by ensitrelvir
How to manage this interaction
This combination is flagged as one to avoid because ensitrelvir can raise sertraline levels in your body. Here's how your care team typically handles this:
- They may adjust timing, choose an alternative, or hold one medicine, tailored to your situation.
- Because ensitrelvir's enzyme-blocking effect lasts for days after the last dose, your team will decide when it's safe to resume a paused medication.
- They may monitor you more closely for side effects.
What you should do: Keep taking your medicines as prescribed and do not stop either one on your own. Let your pharmacist or prescriber know you take both, and report any new nausea, restlessness, tremor, or racing heartbeat.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) When midazolam (a CYP3A substrate) was given as a single 2 mg oral dose together with ensitrelvir at the clinical dose (375 mg on day 1 and 125 mg on days 2 to 5) on Day 5, the Cmax of midazolam rose approximately 2.80-fold and its AUC(0 to inf) rose 6.77-fold relative to midazolam given by itself. Additionally, when dexAMETHasone (a single 1 mg dose) was given together with ensitrelvir (750 mg on day 1 and 250 mg on days 2 to 5, twice the recommended dose) on day 5, and given alone on day 9 (5 days after the final ensitrelvir dose) and day 14 (10 days after the final ensitrelvir dose), the results were an approximately 1.47-fold increase in Cmax and a 3.47-fold increase in AUC(0 to inf) of dexAMETHasone on day 5, a 1.24-fold increase in Cmax and 2.38-fold increase in AUC(0 to inf) on day 9, and a 1.17-fold increase in Cmax and a 1.58-fold increase in AUC(0 to inf) on day 14, compared with dexAMETHasone given alone 1.
Common questions
Can I take Sertraline and Ensitrelvir together?
Ensitrelvir strongly blocks the enzyme that helps clear sertraline, so sertraline levels can rise and this pairing is labeled as one to avoid. Do not change your medicines on your own; check with your pharmacist or doctor about timing or alternatives. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Sertraline and Ensitrelvir 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 is the Sertraline and Ensitrelvir interaction managed?
This combination is flagged as one to avoid because ensitrelvir can raise sertraline levels in your body. Here's how your care team typically handles this: They may adjust timing, choose an alternative, or hold one medicine, tailored to your situation. Because ensitrelvir's enzyme-blocking effect lasts for days after the last dose, your team will decide when it's safe to resume a paused medication… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Sertraline or Ensitrelvir 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: XOCOVA® oral tablets, ensitrelvir oral tablets. Shionogi Inc. Florham Park, NJ, 2026.
Keep reading about Sertraline
Keep reading about Ensitrelvir
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