Lansoprazole and Amoxicillin Interaction
Drug interaction information between Lansoprazole and Amoxicillin.
Lansoprazole and Amoxicillin have a documented major interaction in FDA labeling.
FDA drug labeling documents a major-severity interaction between Lansoprazole and Amoxicillin. 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.
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.
Lansoprazole Also Interacts With
- Clarithromycin major
- Rifampin moderate
- Tacrolimus Topical moderate
- Warfarin minor
- Methotrexate minor
Amoxicillin Also Interacts With
- Rabeprazole major
- Theophylline major
- Allopurinol moderate
- Probenecid moderate
- Estradiol minor
Frequently Asked Questions
Can I take Lansoprazole and Amoxicillin 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 Lansoprazole and Amoxicillin?
This interaction is classified as "major" severity by the FDA. Major interactions may be life-threatening or cause serious side effects.
Why do Lansoprazole and Amoxicillin 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 Lansoprazole and Amoxicillin Interaction
FDA-approved prescribing information for these two drugs flags their combination as a major-severity interaction. Lansoprazole belongs to the Proton Pump Inhibitor (PPI) class and Amoxicillin belongs to the Penicillin Antibiotic 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. Lansoprazole has 14 total documented interactions on file in this dataset, and Amoxicillin has 12. 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 Lansoprazole or Amoxicillin 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.
Read our methodology - how this data is sourced, computed, and verified.