Drug Interactions between maraviroc and vimseltinib

MONITOR: Coadministration with inhibitors of the CYP450 3A4 isoenzyme and/or P-glycoprotein efflux transporter may increase the plasma concentrations of maraviroc, which is a substrate of both. According to the product labeling, administration of maraviroc (100 mg twice a day) with the potent CYP450 3A4/P-glycoprotein inhibitor ketoconazole (400 mg once a day) increased the mean maraviroc peak plasma concentration (Cmax) and systemic exposure (AUC) by approximately 3.5- and 5-fold, respectively, compared to administration alone. When the same dosage of maraviroc was administered with ritonavir (100 mg twice a day), maraviroc Cmax increased by nearly 1.3-fold and AUC by 2.6-fold. An even greater increase of nearly 5-fold in Cmax and 10-fold in AUC was observed during coadministration of maraviroc and saquinavir/ritonavir (1000 mg/100 mg twice a day). At 300 mg twice a day, mean maraviroc Cmax increased by approximately 2-fold and AUC by 3.6-fold during coadministration with atazanavir (400 mg once a day). When the same dosage of maraviroc was given with atazanavir/ritonavir (300 mg/100 mg once a day), maraviroc Cmax increased by 2.7-fold and AUC increased by nearly 5-fold. During coadministration with lopinavir/ritonavir (400 mg/100 mg twice a day), maraviroc Cmax and AUC increased by 2-fold and 4-fold, respectively.

MANAGEMENT: Caution is advised when maraviroc is used with inhibitors of CYP450 3A4 and/or P-glycoprotein. Dosage adjustment for maraviroc may be necessary if an interaction is suspected.