<p>Aprepitant is a substrate, a weak-to-moderate (dose dependent) inhibitor, and an inducer of CYP3A4. Aprepitant is also an inducer of CYP2C9. Precautions should be taken while coadministering Aprepitant with drugs that use CYP3A4 or CYP2C9, for example- Warfarin, Tolbutamide, Phenytoin, Ketoconazole, Itraconazole, Nefazodone, Troleandomycin, Clarithromycin, Ritonavir, Nelfinavir, Diltiazem, Rifampin, Carbamazepine etc. &nbsp;<br />
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Upon coadministration with Aprepitant, the efficacy of hormonal contraceptives during and for 28 days following the last dose of Aprepitant may be reduced. Alternative or back-up methods of contraception should be used during treatment with Aprepitant and for 1 month following the last dose of Aprepitant.</p>