Ketoconazole and Aprepitant Interaction

Drug interaction information between Ketoconazole and Aprepitant.

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

FDA drug labeling documents a moderate-severity interaction between Ketoconazole 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

Ketoconazole

Azole Antifungal

Drug B

Aprepitant

NK1 Receptor Antagonist (Antiemetic)

How They Interact

Ketoconazole strongly blocks the enzymes that clear aprepitant from your body, causing drug levels to rise.

FDA Label Information

Intervention Avoid concomitant use of aprepitant Examples Moderate inhibitor: diltiazem Strong inhibitors: ketoconazole, itraconazole, nefazodone, troleandomycin, clarithromycin, ritonavir, nelfinavir Strong CYP3A4 Inducers Clinical Impact Substantially decreased exposure of aprepitant in patients chronically taking a strong CYP3A4 inducer may decrease the efficacy of aprepitant [see Clinical Pharmacology ( 12.3 )] . Intervention Avoid concomitant use of aprepitant Examples Moderate inhibitor: diltiazem Strong inhibitors: ketoconazole, itraconazole, nefazodone, troleandomycin,...

Frequently Asked Questions

What SPL severity band is on file for Ketoconazole + 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?

Ketoconazole has 113 labeled pairs on file vs Aprepitant's 22. In the moderate band specifically: Ketoconazole has 22 (also Alprazolam, Budesonide/Formoterol, Dexamethasone, Fesoterodine); Aprepitant has 9 (also Alprazolam, Diltiazem, Methylprednisolone, Clarithromycin).

What mechanism field is on file for Ketoconazole and Aprepitant?

Ketoconazole strongly blocks the enzymes that clear aprepitant from your body, causing drug levels to rise.

Ketoconazole carries more major-labeled pairs than Aprepitant

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

Ketoconazole has 6 major-labeled pairs vs Aprepitant's 1. This page itself is in the moderate band, not the major band.

Ketoconazole

6 major · 22 moderate · 85 minor · 113 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.