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Amoxicillin and Lansoprazole Interaction

Drug interaction information between Amoxicillin and Lansoprazole.

Amoxicillin and Lansoprazole have a documented major interaction in FDA labeling.

FDA drug labeling documents a major-severity interaction between Amoxicillin and Lansoprazole. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.

Drug A

Amoxicillin

Penicillin Antibiotic

Drug B

Lansoprazole

Proton Pump Inhibitor (PPI)

How They Interact

Using these drugs together as part of a treatment plan can increase the risk of side effects or change how other medicines work.

What To Do

Check with your doctor to make sure this combination is safe with your other medications.

FDA Label Information

Combination Therapy with Clarithromycin and Amoxicillin Clinical Impact: Concomitant administration of clarithromycin with other drugs can lead to serious adverse reactions, including potentially fatal arrhythmias, and are contraindicated. Amoxicillin also has drug interactions. See Drug Interactions in prescribing information for amoxicillin.

Frequently Asked Questions

Can I take Amoxicillin and Lansoprazole together?

This is a major interaction. Check with your doctor to make sure this combination is safe with your other medications.

How serious is the interaction between Amoxicillin and Lansoprazole?

This interaction is classified as "major" severity by the FDA. Major interactions may be life-threatening or cause serious side effects.

Why do Amoxicillin and Lansoprazole interact?

Using these drugs together as part of a treatment plan can increase the risk of side effects or change how other medicines work.

Understanding the Amoxicillin and Lansoprazole Interaction

FDA-approved prescribing information for these two drugs flags their combination as a major-severity interaction. Amoxicillin belongs to the Penicillin Antibiotic class and Lansoprazole belongs to the Proton Pump Inhibitor (PPI) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Using these drugs together as part of a treatment plan can increase the risk of side effects or change how other medicines work. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.

Context around a specific patient determines real-world impact. Amoxicillin has 12 total documented interactions on file in this dataset, and Lansoprazole has 14. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Check with your doctor to make sure this combination is safe with your other medications. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.

An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Amoxicillin or Lansoprazole based on a web page, speak with your prescriber or pharmacist before making any change.

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.