Rifampin and Losartan Interaction
Drug interaction information between Rifampin and Losartan.
Rifampin and Losartan have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Rifampin and Losartan. 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
Rifampin speeds up the breakdown of losartan in your body, which lowers the amount of medicine available to work.
FDA Label Information
Substitute non-enzyme inducing therapies at least 2 weeks prior to initiation of irinotecan therapy Decrease irinotecan and active metabolite exposure Levothyroxine Decrease exposure Losartan Parent Decrease AUC by 30% Active metabolite (E3174) Decrease AUC by 40% Methadone In patients well-stabilized on methadone, concomitant administration of rifampin resulted in a marked reduction in serum methadone levels and a concurrent appearance of withdrawal symptoms.
Rifampin Also Interacts With
- Darunavir major
- Bictegravir/Emtricitabine/Tenofovir major
- Glecaprevir/Pibrentasvir major
- Nirmatrelvir/Ritonavir major
- Pitavastatin major
Losartan Also Interacts With
- Aliskiren major
- Lithium moderate
- Fluconazole minor
- Glecaprevir/Pibrentasvir minor
- Hydrochlorothiazide minor
Frequently Asked Questions
What SPL severity band is on file for Rifampin + Losartan?
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?
Rifampin has 137 labeled pairs on file vs Losartan's 10. In the minor band specifically: Rifampin has 103 (also Metoprolol, Simvastatin, Glipizide, Propranolol); Losartan has 8 (also Fluconazole, Glecaprevir/Pibrentasvir, Hydrochlorothiazide, Hydrochlorothiazide).
What mechanism field is on file for Rifampin and Losartan?
Rifampin speeds up the breakdown of losartan in your body, which lowers the amount of medicine available to work.
Rifampin carries more major-labeled pairs than Losartan
SPL source-record counts only. This page's band is minor · classes on file: Rifampin (Rifamycin Antibiotic); Losartan (Angiotensin II Receptor Blocker (ARB)).
Rifampin has 8 major-labeled pairs vs Losartan's 1. This page itself is in the minor band, not the major band.
8 major · 26 moderate · 103 minor · 137 total
- Other minor peers for Rifampin
- Metoprolol
- Simvastatin
- Glipizide
- Propranolol
1 major · 1 moderate · 8 minor · 10 total
- Other minor peers for Losartan
- Fluconazole
- Glecaprevir/Pibrentasvir
- Hydrochlorothiazide
- Hydrochlorothiazide
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.