- For patients on oral corticosteroids, they must be stable clinically on corticosteroids or tapered off prior to starting the study drug. For patients taking dexamethasone, the dose should not exceed 8 mg qd (or 4 mg twice a day), if clinically stable, and the dose should not be escalated over entry dose level, if clinically possible. The patient's dose of dexamethasone will be evaluated by the PI, the patient's study physician, and/or the study pharmacist on a case by case basis for safety. All doses of oral corticosteroids will be reduced by 50% to avoid drug to drug interactions with Aprepitant, unless oral corticosteroids are at physiologic dose (e.g. dexamethasone 1 mg, prednisone 10 mg, or cortisone 30 mg). It is recommended that oral corticosteroid doses be escalated back to full dose on Day 7 (2 days after Aprepitant is discontinued) based on Aprepitant half-life pharmacokinetic data, and expert clinical opinion.