No formal drug-drug interaction studies have been conducted with Mometasone Furoate. Inhibitors of Cytochrome P450 3A4: Studies have shown that mometasone furoate is primarily and extensively metabolized in the liver of all species investigated and undergoes extensive metabolism to multiple metabolites. In vitro studies have confirmed the primary role of cytochrome CYP 3A4 in the metabolism of this compound. Coadministration with ketoconazole, a potent CYP 3A4 inhibitor, may increase the plasma concentrations of mometasone furoate.