Amoxicillin and Theophylline Interaction
Drug interaction information between Amoxicillin and Theophylline.
Amoxicillin and Theophylline have a documented major interaction in FDA labeling.
FDA drug labeling documents a major-severity interaction between Amoxicillin and Theophylline. 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
Amoxicillin does not change the way your body processes or removes theophylline.
What To Do
No special changes to your medication are usually needed when taking these together.
FDA Label Information
albuterol, systemic and inhaled mebendazole amoxicillin medroxyprogesterone ampicillin, with or without sulbactam methylprednisolone atenolol metronidazole azithromycin metoprolol caffeine, dietary ingestion nadolol cefaclor nifedipine co-trimoxazole (trimethoprim and sulfamethoxazole) nizatidine diltiazem norfloxacin dirithromycin ofloxacin enflurane omeprazole famotidine prednisone, prednisolone felodipine ranitidine finasteride rifabutin hydrocortisone roxithromycin isoflurane Sorbitol (purgative doses do not inhibit theophylline absorption) isoniazid sucralfate isradipine terbutaline,...
Amoxicillin Also Interacts With
- Lansoprazole major
- Rabeprazole major
- Allopurinol moderate
- Probenecid moderate
- Estradiol minor
Theophylline Also Interacts With
- Metoprolol major
- Albuterol major
- Omeprazole major
- Famotidine major
- Prednisone major
Frequently Asked Questions
Can I take Amoxicillin and Theophylline together?
This is a major interaction. No special changes to your medication are usually needed when taking these together.
How serious is the interaction between Amoxicillin and Theophylline?
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 Theophylline interact?
Amoxicillin does not change the way your body processes or removes theophylline.
Understanding the Amoxicillin and Theophylline 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 Theophylline belongs to the Methylxanthine Bronchodilator class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Amoxicillin does not change the way your body processes or removes theophylline. 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 Theophylline has 86. 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: No special changes to your medication are usually needed when taking these together. 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 Theophylline 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.