This document discusses olanzapine, an atypical antipsychotic drug that is also used as an antiemetic to treat chemotherapy-induced nausea and vomiting (CINV). CINV is classified into 4 types: acute (within 24 hours), delayed (24-48 hours post-chemo), anticipatory (before chemo), and refractory (despite treatment). Olanzapine targets multiple receptor types and has the ability to block dopamine, serotonin, adrenergic, histamine, and muscarinic receptors. The standard dosage is 5-10 mg daily with a maximum of 20 mg, and it can also be given as a rescue dose of 5 mg every 4 hours. Common side effects include som