PlainMeds provides educational information only. This is not medical advice. Always consult your doctor or pharmacist.

Metoprolol and Theophylline Interaction

Drug interaction information between Metoprolol and Theophylline.

Metoprolol and Theophylline have a documented major interaction in FDA labeling.

FDA drug labeling documents a major-severity interaction between Metoprolol 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.

Drug A

Metoprolol

Beta-Blocker

Drug B

Theophylline

Methylxanthine Bronchodilator

How They Interact

Metoprolol is a beta-blocker that can block the airway-opening effects of theophylline. This combination can make it harder for you to breathe and may change the amount of medicine in your blood.

What To Do

Your doctor may need to adjust your dosages or monitor your blood levels closely. Report any new breathing difficulties to your healthcare provider immediately.

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,...

Metoprolol Also Interacts With

View all Metoprolol interactions →

Frequently Asked Questions

Can I take Metoprolol and Theophylline together?

This is a major interaction. Your doctor may need to adjust your dosages or monitor your blood levels closely. Report any new breathing difficulties to your healthcare provider immediately.

How serious is the interaction between Metoprolol 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 Metoprolol and Theophylline interact?

Metoprolol is a beta-blocker that can block the airway-opening effects of theophylline. This combination can make it harder for you to breathe and may change the amount of medicine in your blood.

Understanding the Metoprolol and Theophylline Interaction

FDA-approved prescribing information for these two drugs flags their combination as a major-severity interaction. Metoprolol belongs to the Beta-Blocker class and Theophylline belongs to the Methylxanthine Bronchodilator class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Metoprolol is a beta-blocker that can block the airway-opening effects of 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. Metoprolol has 18 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: Your doctor may need to adjust your dosages or monitor your blood levels closely. 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 Metoprolol 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.