Omeprazole and Darunavir: 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
Darunavir
No brand names on recordOmeprazole
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.
You're taking darunavir (an HIV medicine) along with omeprazole (a stomach acid medicine like Prilosec). These two can affect each other. Your body may not always keep omeprazole at a steady level, so sometimes it may work less well for your heartburn or reflux, and other times it could build up a bit more than expected.
The good news is this is very manageable. Your care team may keep an eye on how well your stomach symptoms are controlled and can fine-tune your omeprazole dose if needed. Please don't change either medicine on your own. Just let your pharmacist or doctor know how you're feeling so they can adjust things safely.
Effect: Altered omeprazole exposure with concurrent darunavir. Reduced omeprazole efficacy is possible, and increased omeprazole exposure may occur via inhibition of CYP3A-mediated metabolism. Darunavir-related adverse reactions may also increase.
- Direction/mechanism: Variable PK effect; omeprazole is a CYP3A/CYP2C19 substrate and darunavir a CYP3A inhibitor. Net effect on file is bidirectional.
- Evidence: Probable. Onset: unspecified.
- Management: Monitor for reduced omeprazole efficacy; consider dose titration if symptoms are uncontrolled, but do not exceed 40 mg/day. Watch for adverse effects if exposure rises.
What happens
Altered (reduced/increased) omeprazole exposure, an increased darunavir-related adverse reactions and reduced efficacy of omeprazole
Interaction Deep Dive
Giving darunavir together with omeprazole may affect omeprazole exposure. In patients receiving both agents, watch for diminished efficacy of omeprazole. A higher omeprazole dose may be considered when a patient's symptoms remain poorly controlled; do not exceed 40 mg of omeprazole per day1. In addition, concurrent use of darunavir and omeprazole (a CYP3A substrate) may raise omeprazole exposure, potentially heightening or extending its therapeutic effect and possibly leading to adverse events 23.
Why it happens (mechanism)
Unknown; inhibition of CYP3A-mediated metabolism of omeprazole
How to manage this interaction
Keep taking both medications exactly as prescribed. Your care team can manage this by watching how well your acid symptoms are controlled and tailoring your omeprazole dose to you.
- Tell your prescriber if your reflux or heartburn symptoms are not well controlled, since your omeprazole dose may need to be adjusted.
- Note that the documented guidance is to avoid more than 40 mg of omeprazole per day in this situation.
- Report any new or bothersome side effects so your team can check whether levels have risen.
Do not start, stop, or change either medicine on your own. Your pharmacist or doctor can adjust and monitor this safely.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) In the drug interaction studies conducted with the coadministration of omeprazole 20 mg once daily together with darunavir/ritonavir 400/100 mg twice daily, the mean ratios for the Cmax, AUC, and Cmin of darunavir with versus without omeprazole were 1.02, 1.04, and 1.08 respectively 1.
b) In the drug interaction studies conducted with the coadministration of a single 40 mg dose of omeprazole together with darunavir/ritonavir 600/100 mg twice daily, the mean ratios for the Cmax and AUC of omeprazole with versus without darunavir were 0.66 and 0.58 respectively 1.
Common questions
Can I take Omeprazole and Darunavir together?
Darunavir can change how omeprazole works, sometimes weakening its acid control and sometimes raising its levels; keep taking both as prescribed and tell your care team if symptoms aren't controlled, but don't exceed 40 mg of omeprazole per day. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Omeprazole and Darunavir 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 is the Omeprazole and Darunavir interaction managed?
Keep taking both medications exactly as prescribed. Your care team can manage this by watching how well your acid symptoms are controlled and tailoring your omeprazole dose to you. Tell your prescriber if your reflux or heartburn symptoms are not well controlled, since your omeprazole dose may need to be adjusted. Note that the documented guidance is to avoid more than 40 mg of omeprazole per day… 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 Omeprazole or Darunavir 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 (3)
- Product Information: PREZISTA(R) oral suspension, oral tablets, darunavir oral suspension, oral tablets. Janssen Products, LP (per FDA), Horsham, PA, 2023. DailyMed
- Product Information: PREZCOBIX® PED oral tablets for suspension, darunavir cobicistat oral tablets for suspension. Janssen Products, LP (per FDA), Horsham, PA, 2026. DailyMed
- Product Information: PREZCOBIX® oral tablets, darunavir cobicistat oral tablets. Janssen Products, LP (per FDA), Horsham, PA, 2026. DailyMed
Keep reading about Darunavir
Keep reading about Omeprazole
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