Key takeaways
Granisetron (Kytril) and olanzapine (Zyprexa) are both used to help with nausea and vomiting related to cancer treatments, but they belong to different medication classes. Granisetron is an antiemetic that works by blocking serotonin to prevent nausea and vomiting, while olanzapine is an atypical antipsychotic that balances chemicals in the brain and is used off-label for nausea. Granisetron is taken orally or by injection, typically on chemotherapy or radiation days, and is available as a generic. Olanzapine is taken once daily by mouth or as an injection for other conditions like schizophrenia and bipolar disorder, and it is also available as a generic. Common side effects of granisetron include headaches and constipation, while olanzapine can cause sleepiness, weight gain, and high blood sugar. Granisetron can interact with medications affecting serotonin levels, increasing the risk of serotonin syndrome, whereas olanzapine can interact with medications that cause drowsiness or affect blood pressure.
