Tasimelteon and Rifampin Interaction
Drug interaction information between Tasimelteon and Rifampin.
Tasimelteon and Rifampin have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Tasimelteon and Rifampin. 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 causes your body to clear tasimelteon much faster than normal. This lowers the amount of medicine in your system and makes it less effective.
FDA Label Information
7 DRUG INTERACTIONS Strong CYP1A2 inhibitors (e.g., fluvoxamine): Avoid use of tasimelteon in combination with strong CYP1A2 inhibitors because of increased exposure ( 7.1 , 12.3 ) Strong CYP3A4 inducers (e.g., rifampin): Avoid use of tasimelteon in combination with rifampin or other CYP3A4 inducers, because of decreased exposure ( 7.2 , 12.3 ) 7.1 Strong CYP1A2 Inhibitors (e.g., fluvoxamine) Avoid use of tasimelteon in combination with fluvoxamine or other strong CYP1A2 inhibitors because of a potentially large increase in tasimelteon exposure and greater risk of adverse reactions [see...
Tasimelteon Also Interacts With
- Fluvoxamine moderate
- Metoprolol minor
- Melatonin minor
- Acebutolol minor
Rifampin Also Interacts With
- Darunavir major
- Bictegravir/Emtricitabine/Tenofovir major
- Glecaprevir/Pibrentasvir major
- Nirmatrelvir/Ritonavir major
- Pitavastatin major
Frequently Asked Questions
What SPL severity band is on file for Tasimelteon + Rifampin?
Compiled FDA labeling labels this pair moderate. 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 Tasimelteon's 5. In the moderate band specifically: Tasimelteon has 2 (also Fluvoxamine); Rifampin has 26 (also Doxycycline, Probenecid, Theophylline, Apixaban).
What mechanism field is on file for Tasimelteon and Rifampin?
Rifampin causes your body to clear tasimelteon much faster than normal. This lowers the amount of medicine in your system and makes it less effective.
Rifampin carries more major-labeled pairs than Tasimelteon
SPL source-record counts only. This page's band is moderate · classes on file: Tasimelteon (Melatonin Receptor Agonist); Rifampin (Rifamycin Antibiotic).
Rifampin has 8 major-labeled pairs vs Tasimelteon's 0. This page itself is in the moderate band, not the major band.
0 major · 2 moderate · 3 minor · 5 total
- Other moderate peers for Tasimelteon
- Fluvoxamine
8 major · 26 moderate · 103 minor · 137 total
- Other moderate peers for Rifampin
- Doxycycline
- Probenecid
- Theophylline
- Apixaban
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.