Inclusion Criteria:

• diagnosis of cancer
• scheduled to receive a chemotherapy treatment containing at least moderately emetogenic chemotherapy:
• chemotherapy to be given in an inpatient setting
• chemotherapy may be for adjuvant, neoadjuvant, curative or palliative intent
• patients may be treatment naive or have been treated previously with chemotherapy
• chemotherapy agents may be given orally, intravenously, or by continuous infusion on one or multiple days
• scheduled to receive a 5-HT3 receptor antagonist antiemetic: ondansetron, granisetron, palonosetron or dolasetron mesylate, dexamethasone with or without a benzodiazepine on the day of treatment according to published antiemetic guidelines or as clinically indicated
• able to understand English (all assessment instruments are in English)
• 18 years of age or older
• informed consent
• self report of at least mild nausea which the patient feels needs rescuing or "moderate nausea" (a score of >2 on a 4 point Likert scale) or at least one episode of emesis since receiving chemotherapy

Exclusion Criteria:

• patients who have received aprepitant as prophylaxis or rescue treatment during the current cycle of chemotherapy
• patients who are pregnant, have positive serum hCG, or are lactating
• patients with clinical evidence of current or impending bowel obstruction (patients with tumor pressing on their bowel) or symptomatic brain metastases
• patients receiving a scheduled dopamine antagonist after chemotherapy
• patients with an allergy to or history of intolerance of any of the study drugs will be excluded from the study
• history of chronic nausea/vomiting without chemotherapy, history of anticipatory nausea/vomiting, or emesis within 24 hours prior to chemotherapy starting