Aprepitant and Deflazacort interaction
Aprepitant and Deflazacort: the Deflazacort prescribing label flags this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Deflazacort (EMFLAZA) label · effective 2025-11-13
Avoid use of moderate or strong CYP3A4 inducers with EMFLAZA, as they may reduce efficacy ( 7.1 )
Avoid concomitant use of strong (e.g., efavirenz) or moderate (e.g., carbamazepine, phenytoin) CYP3A4 inducers with EMFLAZA [see Dosage and Administration ( 2.5 ) and Clinical Pharmacology ( 12.3 )] .
Moderate or strong CYP3A4 inhibitors: Give one third of the recommended dosage of EMFLAZA ( 7.1 )
Co-administration of deflazacort with clarithromycin, a strong CYP3A4 inhibitor, increased total exposure to 21-desDFZ by about 3-fold.
Therefore, give one third the recommended dosage of EMFLAZA when moderate or strong CYP3A4 inhibitors (e.g., clarithromycin, fluconazole, diltiazem, verapamil, grapefruit juice) are used concomitantly with EMFLAZA [see Dosage and Administration ( 2.5 ) and Clinical Pharmacology ( 12.3 )] .
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.