Samtidig administration af (fos) aprepitant og lægemidler, som er stærke induktorer af CYP3A4 - aktivitet (fx rifampicin, phenytoin, carbamazepin, phenobarbital) bør undgås, da kombinationen medfører reducerede plasmakoncentrationer af aprepitant, hvilket kan resultere i nedsat virkning.
Concomitant administration of fosaprepitant or aprepitant with medicinal products that strongly induce CYP3A4 activity (e. g. rifampicin, phenytoin, carbamazepine, phenobarbital) should be avoided as the combination results in reductions of the plasma concentrations of aprepitant that may result in decreased efficacy.