Bismuth Subsalicylate and Doxycycline Interaction
Drug interaction information between Bismuth Subsalicylate and Doxycycline.
Bismuth Subsalicylate and Doxycycline have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Bismuth Subsalicylate and Doxycycline. 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
Bismuth subsalicylate prevents your body from properly absorbing the antibiotic into your bloodstream.
FDA Label Information
Absorption of tetracyclines is impaired by bismuth subsalicylate.
Bismuth Subsalicylate Also Interacts With
- Doxycycline Hyclate minor
- Omadacycline minor
Doxycycline Also Interacts With
- Tetracycline moderate
- Rifampin moderate
- Carbamazepine minor
- Phenytoin minor
- Doxycycline Hyclate minor
Frequently Asked Questions
What SPL severity band is on file for Bismuth Subsalicylate + Doxycycline?
Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Doxycycline has 9 labeled pairs on file vs Bismuth Subsalicylate's 3. In the minor band specifically: Bismuth Subsalicylate has 3 (also Doxycycline Hyclate, Omadacycline); Doxycycline has 7 (also Carbamazepine, Phenytoin, Doxycycline Hyclate, Ethinyl Estradiol).
What mechanism field is on file for Bismuth Subsalicylate and Doxycycline?
Bismuth subsalicylate prevents your body from properly absorbing the antibiotic into your bloodstream.
Doxycycline's labeled portfolio outnumbers Bismuth Subsalicylate
SPL source-record counts only. This page's band is minor · classes on file: Bismuth Subsalicylate (Antidiarrheal / Antacid); Doxycycline (Tetracycline Antibiotic).
0 major · 0 moderate · 3 minor · 3 total
- Other minor peers for Bismuth Subsalicylate
- Doxycycline Hyclate
- Omadacycline
0 major · 2 moderate · 7 minor · 9 total
- Other minor peers for Doxycycline
- Carbamazepine
- Phenytoin
- Doxycycline Hyclate
- Ethinyl Estradiol
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.