Theophylline and Felodipine Interaction
Drug interaction information between Theophylline and Felodipine.
Theophylline and Felodipine have a documented major interaction in FDA labeling.
FDA drug labeling documents a major-severity interaction between Theophylline and Felodipine. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
This blood pressure drug does not change the amount of theophylline that stays in your blood or how the liver handles it.
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,...
Theophylline Also Interacts With
- Metoprolol major
- Albuterol major
- Omeprazole major
- Amoxicillin major
- Famotidine major
Felodipine Also Interacts With
- Itraconazole major
- Nirmatrelvir/Ritonavir moderate
- Metoprolol minor
- Spironolactone minor
- Ketoconazole minor
Frequently Asked Questions
What SPL severity band is on file for Theophylline + Felodipine?
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 Felodipine's 18. In the major band specifically: Theophylline has 27 (also Metoprolol, Albuterol, Omeprazole, Amoxicillin); Felodipine has 2 (also Itraconazole).
What mechanism field is on file for Theophylline and Felodipine?
This blood pressure drug does not change the amount of theophylline that stays in your blood or how the liver handles it.
Theophylline carries more major-labeled pairs than Felodipine
SPL source-record counts only. This page's band is major · classes on file: Theophylline (Methylxanthine Bronchodilator); Felodipine (Calcium Channel Blocker).
Theophylline has 27 major-labeled pairs vs Felodipine's 2.
27 major · 5 moderate · 54 minor · 86 total
- Other major peers for Theophylline
- Metoprolol
- Albuterol
- Omeprazole
- Amoxicillin
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.
Read our methodology - how this data is sourced, computed, and verified.