Piperaquine and Omeprazole: 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
Piperaquine
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.
Here's what's going on. Piperaquine, a medicine used to treat malaria, can slow down a liver enzyme (called CYP2C19) that your body uses to break down omeprazole. When that enzyme is slowed, omeprazole can build up a bit more in your system than usual.
Because piperaquine stays in the body for a long time, this effect can linger for up to 3 months after you stop it. The good news is that this is a theoretical concern, and your care team can manage it easily by keeping an eye on how you're doing and adjusting things if needed. Please don't stop either medicine on your own, just check in with your pharmacist or doctor.
Mechanism: Piperaquine inhibits CYP2C19, the primary enzyme metabolizing omeprazole (an active drug, not a prodrug). Expect increased omeprazole exposure (higher AUC/Cmax) and potentially enhanced acid suppression.
- Direction: increased omeprazole effect.
- Onset: unspecified; note piperaquine's long half-life means the effect may persist up to 3 months after discontinuation.
- Evidence: theoretical.
- Severity: moderate.
Management: If co-administration is required, use caution and monitor clinically. Omeprazole dosing may be individualized by the care team. Maintain vigilance for up to 3 months post-piperaquine.
What happens
Increased exposure of CYP2C19 substrates
Interaction Deep Dive
When piperaquine (which inhibits CYP2C19) is given at the same time as a substrate of CYP2C19, exposure to that substrate may rise. Because piperaquine has a long half-life, caution should be exercised when a CYP2C19 substrate is used for as long as 3 months following the end of piperaquine treatment1. Should the two need to be given together, proceed cautiously and keep the patient under close observation.
Why it happens (mechanism)
Inhibition of CYP2C19-mediated metabolism by piperaquine
How to manage this interaction
What your care team may do:
- Keep you on both medicines when they're both needed, while watching you a little more closely.
- Individualize your omeprazole dose if that seems appropriate for you.
- Stay watchful for up to 3 months after piperaquine is stopped, since it clears slowly.
What you can do:
- Keep taking both exactly as prescribed unless told otherwise.
- Mention any new or stronger side effects to your pharmacist or prescriber.
- Remind any provider that you recently took piperaquine, even a couple months later.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Piperaquine and Omeprazole together?
Piperaquine can raise omeprazole levels by slowing the enzyme that clears it, and this may linger for up to 3 months after piperaquine stops. Keep taking both as prescribed and let your care team monitor and adjust if needed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Piperaquine and Omeprazole interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Piperaquine and Omeprazole interaction managed?
What your care team may do: Keep you on both medicines when they're both needed, while watching you a little more closely. Individualize your omeprazole dose if that seems appropriate for you. Stay watchful for up to 3 months after piperaquine is stopped, since it clears slowly. What you can do: Keep taking both exactly as prescribed unless told otherwise. Mention any new or stronger side effects… 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 Piperaquine or Omeprazole 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 anything you'd monitor while I'm on both?
References (1)
- Product Information: Eurartesim oral film-coated tablets, piperaquine tetraphosphate dihydroartemisinin oral film-coated tablets. Sigma-Tau Industrie Farmaceutiche Riunite S.p.A (per EMA), Rome, Italy, 2012.
Keep reading about Piperaquine
Keep reading about Omeprazole
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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