Efficacy and Safety of Olanzapine for the Treatment of Nausea and Vomiting in Palliative Cancer Care

Inclusion Criteria: 1. Age 18-65 years. 2. Diagnosis of advanced malignancy. 3. Failed two standard medications for nausea/vomiting (after 6 hours from last dose). 4. Adequate organ function, including the following: 1. Hepatic: bilirubin ≤1.5 times the upper limit of normal (x ULN); aspartate aminotransferase (AST), and alanine aminotransferase (ALT) ≤3.0 x ULN (AST, and ALT ≤5 x ULN is acceptable if liver has tumor involvement), alkaline phosphatase (AP) ≤5.0 x ULN. 2. Renal: calculated creatinine clearance (CrCl) ≥30 mL/min based on the original weight based Cockcroft and Gault formula. 5. Expected life expectancy \> 1 month. 6. Patients must be able to read Thai. 7. Patients must sign an informed consent document. Exclusion Criteria: 1. Patients with history of abdominal radiotherapy. 2. Patients who receive chemotherapy within 1 week. 3. Patients who take fluoxetine. 4. Patients with heart failure or myocardial infarction in the past 6 months. 5. Patients with QTc prolongation from baseline ECG. 6. Known hypersensitivity to olanzapine. 7. Patients who are unwilling to participate in the study.