Used primarily to prevent nausea and vomiting associated with chemotherapy, radiation therapy, and surgery. It acts by blocking serotonin receptors in the gastrointestinal tract and central nervous system, making it effective in managing acute and delayed chemotherapy-induced nausea. Also utilized in postoperative settings to reduce the incidence of vomiting, especially in patients undergoing procedures with high emetic risk. Its long half-life allows for once-daily dosing, improving patient compliance.