Study stopped due to lower than expected accrual.

The purpose of this research is to compare two drugs that are routinely used as standard of care for treating nausea and vomiting caused by chemotherapy. This study aims to see if the drug olanzapine is as good as the steroid drug dexamethasone for preventing nausea and vomiting after chemotherapy. Both drugs are listed as appropriate treatment options in the most recent version of National Comprehensive Cancer Network guidelines on Antiemesis.

The study will include patients treated with high emetogenic chemotherapy (HEC) or moderate emetogenic chemotherapy (MEC). Emetogenic means that it may cause nausea and vomiting. Your participation will last for 2 cycles of chemotherapy.

For patients given high emetogenic chemotherapy (HEC):

As standard of care for nausea and vomiting after high emetogenic chemotherapy (HEC), subjects will receive fosaprepitant 150 mg IV once, palonosetron 0.25 mg IV once, dexamethasone 12 mg oral or IV once on day 1.

Patients will be randomly assigned to either the DEX group to receive dexamethasone or to the OLA group to receive olanzapine for the first cycle of chemotherapy.

1. DEX group: dexamethasone (Decadron) 8 mg oral daily on days 2-4.
2. OLA group: olanzapine (Zyprexa)10 mg oral each night on days 1-4. For the second cycle of chemotherapy, the subject will switch to the other group. For future cycles of chemotherapy, the subject will choose the drug that worked best.

For patients give moderate emetogenic chemotherapy (MEC):

As standard of care for nausea and vomiting after moderate emetogenic chemotherapy (MEC), subjects will receive granisetron 2 mg oral once and, dexamethasone 12 mg oral once on day 1.

Subjects will be randomly assigned to either the DEX group to receive dexamethasone or to the OLA group to receive olanzapine for the first cycle of chemotherapy.

1. DEX group: dexamethasone (Decadron) 8 mg oral daily on days 2-3.
2. OLA group: olanzapine (Zyprexa)10 mg oral each night on days 1-3. For the second cycle of chemotherapy, the subject will switch to the other group. For future cycles of chemotherapy, the subject will choose the drug that worked best.

Subjects (both HEC and MEC) will be asked to complete a survey prior to treatment on Day 1 of cycle 1 and cycle 2 prior to treatment. On Day 2 and Day 6 a member of the study will contact subjects by phone to complete another survey on any symptoms you may be experiencing.

Inclusion Criteria:

• 18 years and older
• confirmed cancer diagnosis
• starting cycle 1 of an FDA approved treatment that is categorized as high-emetogenic (nausea and vomiting inducing) chemotherapy per National Comprehensive Cancer Network® guidelines
• Eastern Cooperative Oncology Group performance score of 0 or 1
• appropriate renal function
• appropriate hepatic function
• appropriate hematologic function.

Exclusion Criteria:

• Patients will be excluded if they experience nausea or vomiting up to 24 hours before chemotherapy,
• currently on a glucocorticoid therapy
• contraindication to glucocorticoid therapy
• taking any medication that has antiemetic properties.
• scheduled or planned to receive radiation within one week of or concurrently with chemotherapy
• brain metastases.