Drug Interactions between aprepitant and ruxolitinib

Coadministration with mild or moderate inhibitors of CYP450 3A4 may modestly increase the plasma concentrations of ruxolitinib, which is primarily metabolized by the isoenzyme. In healthy subjects, administration of a single 10 mg dose of ruxolitinib following pretreatment with the moderate CYP450 3A4 inhibitor erythromycin (500 mg twice daily for four days) resulted in an 8% increase in ruxolitinib peak plasma concentration (Cmax) and a 27% increase in systemic exposure (AUC) compared to administration of ruxolitinib alone. The change in the pharmacodynamic marker, pSTAT3 inhibition, was consistent with the corresponding exposure information. No dosage adjustment is recommended when ruxolitinib is coadministered with mild or moderate CYP450 3A4 inhibitors. However, clinical data for topical ruxolitinib are not available. Consultation with individual package labeling, as well as relevant institutional protocols, may be advisable for further guidance.