Rifampin and Aprepitant Interaction

Drug interaction information between Rifampin and Aprepitant.

Rifampin and Aprepitant have a documented moderate interaction in FDA labeling.

FDA drug labeling documents a moderate-severity interaction between Rifampin and Aprepitant. 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

Rifampin

Rifamycin Antibiotic

Drug B

Aprepitant

NK1 Receptor Antagonist (Antiemetic)

How They Interact

Rifampin causes your body to process aprepitant much faster than normal, which can make the aprepitant stop working.

FDA Label Information

Intervention Avoid concomitant use of aprepitant Examples rifampin, carbamazepine, phenytoin 7.1 Effect of Aprepitant on the Pharmacokinetics of Other Drugs Aprepitant is a substrate, a weak-to-moderate (dose-dependent) inhibitor, and an inducer of CYP3A4. Intervention Avoid concomitant use of aprepitant Examples rifampin, carbamazepine, phenytoin

Frequently Asked Questions

What SPL severity band is on file for Rifampin + Aprepitant?

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 Aprepitant's 22. In the moderate band specifically: Rifampin has 26 (also Doxycycline, Probenecid, Theophylline, Apixaban); Aprepitant has 9 (also Alprazolam, Diltiazem, Methylprednisolone, Ketoconazole).

What mechanism field is on file for Rifampin and Aprepitant?

Rifampin causes your body to process aprepitant much faster than normal, which can make the aprepitant stop working.

Rifampin carries more major-labeled pairs than Aprepitant

SPL source-record counts only. This page's band is moderate · classes on file: Rifampin (Rifamycin Antibiotic); Aprepitant (NK1 Receptor Antagonist (Antiemetic)).

Rifampin has 8 major-labeled pairs vs Aprepitant's 1. This page itself is in the moderate band, not the major band.

Rifampin

8 major · 26 moderate · 103 minor · 137 total

Aprepitant

1 major · 9 moderate · 12 minor · 22 total

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.