Do not use IVEMEND • If you are allergic (hypersensitive) to fosaprepitant (which is converted to aprepitant in your body), aprepitant, or to polysorbate 80 or any of the other ingredients. • With medicines containing pimozide (used to treat psychiatric illnesses), terfenadine and astemizole (used for hay fever and other allergic conditions), cisapride (used for treating gastrointestinal motility disorders).