Theophylline and Tetracycline Interaction

Drug interaction information between Theophylline and Tetracycline.

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

FDA drug labeling documents a major-severity interaction between Theophylline and Tetracycline. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.

Drug A

Theophylline

Methylxanthine Bronchodilator

Drug B

Tetracycline

Tetracycline Antibiotic

How They Interact

This antibiotic does not significantly change how fast your liver breaks down theophylline, so the drug levels in your blood should stay the same.

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,...

Frequently Asked Questions

What SPL severity band is on file for Theophylline + Tetracycline?

Compiled FDA labeling labels this pair major. That is a source-record field, not an individual medication-combination decision.

Which drug in this pair has the larger labeled-interaction portfolio?

Theophylline has 86 labeled pairs on file vs Tetracycline's 12. In the major band specifically: Theophylline has 27 (also Metoprolol, Albuterol, Omeprazole, Amoxicillin); Tetracycline has 1.

What mechanism field is on file for Theophylline and Tetracycline?

This antibiotic does not significantly change how fast your liver breaks down theophylline, so the drug levels in your blood should stay the same.

Theophylline carries more major-labeled pairs than Tetracycline

SPL source-record counts only. This page's band is major · classes on file: Theophylline (Methylxanthine Bronchodilator); Tetracycline (Tetracycline Antibiotic).

Theophylline has 27 major-labeled pairs vs Tetracycline's 1.

Theophylline

27 major · 5 moderate · 54 minor · 86 total

Tetracycline

1 major · 3 moderate · 8 minor · 12 total

Tetracycline has no other major-band peer in this dataset besides Theophylline.

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.