Omeprazole and Clarithromycin: 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
Clarithromycin
Omeprazole
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've been prescribed clarithromycin (an antibiotic) and omeprazole (a stomach acid medicine). When taken together, the levels of both drugs can rise. The omeprazole helps push more clarithromycin into your stomach lining, and the clarithromycin slows down how your body clears the omeprazole, so more of each sticks around.
The good news is that this combination is sometimes used on purpose to treat stomach ulcers and H. pylori infection. Your care team can manage this by choosing the right doses and watching how you feel. Don't stop either medicine on your own. Just check with your pharmacist or doctor if you have questions or notice new side effects.
Effect: Bidirectional increase in exposure. Omeprazole raises clarithromycin concentrations in gastric tissue/mucus (partly via gastric pH and mucus changes), and clarithromycin, a strong CYP3A4 inhibitor, reduces CYP3A4-mediated omeprazole metabolism, increasing omeprazole exposure.
- Direction: Increased levels of both agents. Neither is a prodrug requiring activation here.
- Severity/Evidence: Major; substantiation probable. Onset unspecified.
- Management: The database advises avoiding concomitant use. Where the combination is used therapeutically (e.g., H. pylori eradication), doses should be individualized by the care team and the patient monitored for tolerability.
What happens
Increased clarithromycin exposure in gastric tissue and mucus and an increased omeprazole exposure
Interaction Deep Dive
The combined use of clarithromycin, which is a potent CYP3A4 inhibitor, together with omeprazole, a CYP3A4 substrate, should be avoided, because giving omeprazole at the same time raised clarithromycin levels in both the gastric tissue and the mucus. On top of this, clarithromycin can inhibit the CYP3A4-mediated metabolism of omeprazole, which may in turn lead to higher omeprazole concentrations1.
Why it happens (mechanism)
Changes in gastric pH and mucus; inhibition of CYP3A4-mediated metabolism of omeprazole
How to manage this interaction
This combination is sometimes used intentionally (for example, to treat H. pylori), so don't stop either drug on your own.
- Keep taking both as prescribed unless your prescriber tells you otherwise.
- Your care team may adjust and individualize your doses and monitor you more closely, since levels of both medicines can rise.
- Tell your pharmacist or doctor about any new or stronger side effects.
- Ask your pharmacist to review all your medicines, as clarithromycin interacts with many other drugs too.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) In drug interaction studies, giving clarithromycin 500 mg every 8 hours together with omeprazole 40 mg once daily to healthy adult participants produced higher steady-state plasma concentrations of clarithromycin, with Cmax, AUC (0 to 24), and half-life rising by 30%, 89%, and 34%, respectively 1.
b) Coadministration of omeprazole raised the plasma concentrations of both clarithromycin and 14-OH clarithromycin. For clarithromycin, when it was given with omeprazole rather than alone, the mean Cmax was 10% higher, the mean Cmin was 27% higher, and the mean AUC (0 to 8) was 15% higher. Comparable findings occurred for 14-OH clarithromycin, with the mean Cmax 45% higher, the mean Cmin 57% higher, and the mean AUC (0 to 8) 45% higher 1.
Common questions
Can I take Omeprazole and Clarithromycin together?
Clarithromycin and omeprazole together can raise the levels of both drugs, so keep taking them as prescribed and let your care team tailor doses and monitor you. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Omeprazole and Clarithromycin 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 Clarithromycin interaction managed?
This combination is sometimes used intentionally (for example, to treat H. pylori), so don't stop either drug on your own. Keep taking both as prescribed unless your prescriber tells you otherwise. Your care team may adjust and individualize your doses and monitor you more closely, since levels of both medicines can rise. Tell your pharmacist or doctor about any new or stronger side effects. Ask y… 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 Clarithromycin 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: VOQUEZNA(TM) TRIPLE PAK(TM) oral kit, vonoprazan oral tablets, amoxicillin oral capsules, clarithromycin oral tablets kit. Phathom Pharmaceuticals (per FDA), Buffalo Grove, IL, 2023. DailyMed
Keep reading about Clarithromycin
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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