- Patient has had prescription or non-prescription drugs or other products (ie, grapefruit juice) known to be sensitive to CYP3A4 substrates or CYP3A4 substrates with a narrow therapeutic index, or to be moderate to strong inhibitors or inducers of CYP3A4, which cannot be discontinued 2 weeks before Day 1 of dosing and withheld throughout the study until 2 weeks after the last dose of study drug. Co-administration of aprepitant during this study is prohibited.