 OUTLINE: Patients receive chemotherapy in combination with a pre-defined standard 5-Hydroxytryptamine-3 5-HT3 antagonist or corticosteroid regimen with or without a benzodiazepine on day 1. If breakthrough nausea or vomiting occurs, patients then receive fosaprepitant dimeglumine IV once per standard administration guidelines. Patients with treatment response may receive additional doses of oral aprepitant once on days 2 and 3. Patients with persistent nauseavomiting after 2 hours and who desire further treatment may receive standard rescue therapy with prochlorperazine, metoclopramide, or haloperidol with or without additional lorazepam until relief, at the discretion of the provider. 