Sertraline and Ketoconazole: 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
Ketoconazole
Sertraline
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.
Let's talk about taking ketoconazole (an antifungal) together with sertraline (an antidepressant). Ketoconazole slows down the liver enzyme that normally clears sertraline out of your body. That means sertraline can build up to higher levels than expected. Both medicines can also affect your heart's rhythm (something called QT prolongation), and taking them together can add to that risk.
Because of this, this combination is generally something doctors avoid. The good news is that this is very manageable. Please don't stop either medicine on your own. Just reach out to your pharmacist or doctor, and they can help you find a safer plan.
Effect: Ketoconazole, a strong CYP3A4 inhibitor, reduces sertraline metabolism, increasing sertraline exposure. Both agents can prolong the QT interval, giving additive QTc risk and potential for ventricular arrhythmias (including torsades).
- Mechanism: CYP3A4 inhibition (increased sertraline AUC/Cmax) plus additive PD QT prolongation. Neither drug is a prodrug.
- Direction: Increased sertraline effect and exposure.
- Evidence: Theoretical; onset unspecified.
- Rating: Contraindicated.
- Management: Avoid coadministration. If both are truly required, consider an alternative agent; otherwise monitor ECG/QTc and electrolytes closely and individualize dosing under specialist guidance.
What happens
Increased sertraline exposure and an increased risk of QT interval prolongation
Interaction Deep Dive
Giving ketoconazole (a potent inhibitor of CYP3A4 with the potential to lengthen the QT interval) together with CYP3A4 substrates recognized for QT prolongation, sertraline being one example, is contraindicated, because it can raise exposure to the CYP3A4 substrate2 and thereby heighten the likelihood of QT prolongation and/or ventricular arrhythmias 1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of sertraline; additive QT interval prolongation
How to manage this interaction
This pairing is flagged as one to avoid, but your care team has clear ways to handle it.
- Keep taking both medicines as prescribed until you speak with your pharmacist or doctor. Don't stop either one on your own.
- Your team may choose an alternative medicine for one of these, since combining them is generally not recommended.
- If both are truly needed, your team may monitor your heart rhythm more closely and adjust doses individually.
- Let your prescriber know if you feel dizzy, faint, or notice a fast or irregular heartbeat.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Sertraline and Ketoconazole together?
Ketoconazole can raise sertraline levels and add to heart-rhythm risk, so this combination is usually avoided. Contact your pharmacist or doctor before making any changes. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Sertraline and Ketoconazole 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 Ketoconazole interaction managed?
This pairing is flagged as one to avoid, but your care team has clear ways to handle it. Keep taking both medicines as prescribed until you speak with your pharmacist or doctor. Don't stop either one on your own. Your team may choose an alternative medicine for one of these, since combining them is generally not recommended. If both are truly needed, your team may monitor your heart rhythm more cl… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
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 Ketoconazole 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: ZOLOFT oral tablets, oral solution, sertraline hydrochloride oral tablets, oral solution. Viatris Specialty LLC (per FDA), Morgantown, WV, 2023. DailyMed
- Product Information: Ketoconazole oral tablet, ketoconazole oral tablet. Taro Pharmaceuticals U.S.A. Inc. (per DailyMed), Hawthorne, NY, 2024. DailyMed
Keep reading about Ketoconazole
Keep reading about Sertraline
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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