Olanzapine for Prevention of Chemotherapy-induced Nausea and Vomiting in Children: A Multi-Centre Feasibility Study

Inclusion Criteria: * 4 to 18 years old * English-speaking and have an English-speaking parent/guardian * Have the minimum cognitive ability of a 4 year old as assessed by a health care professional * Scheduled to receive moderately to highly emetogenic chemotherapy as assessed using the Pediatric Oncology Group of Ontario Guideline for emetogenicity Classification of Antineoplastic Agents in Children on at least one day of a course of chemotherapy * Scheduled to receive either ondansetron, granisetron or palonosetron with or without dexamethasone on a scheduled basis as ordered by the patient's clinical team as per the usual antiemetic standard of care * Weigh at least 14kg * Have serum total bilirubin ≤ 3 mg/dl (50 µmol/L), and ALT and AST ≤ 3x upper limit of normal for age * Consent to use adequate contraception or remain abstinent on each day olanzapine is given and for 5 days afterward if of child-bearing potential Exclusion Criteria: * Brain tumor patients * Have had treatment within 14 days prior to study enrollment with olanzapine or 30 days prior to study enrollment with another antipsychotic agent * Planned to receive amifostine, CYP1A2 inducers or inhibitors, other antipsychotic agents or quinolone antibiotics while receiving olanzapine; * Have uncontrolled hypertension * Receive other antipsychotic agents, amifostine, citalopram, CYP1A2 inducers or inhibitors, quinolone antibiotics while receiving olanzapine * Receive scopolamine patches, phenothiazines, acupressure or acupuncture during the study period * Planned to receive any antiemetic agents other than dexamethasone, ondansetron, granisetron, palonosetron, aprepitant or fosaprepitant on a scheduled basis * Have a history of neuroleptic malignant syndrome, a seizure disorder, hypersensitivity to olanzapine, cardiac arrhythmias including prolonged QT, low left ventricular ejection fraction, or a history of uncontrolled diabetes mellitus * Are pregnant or breast-feeding