Tropisetron is primarily used as an antiemetic to prevent nausea and vomiting, particularly in patients undergoing chemotherapy, radiation therapy, or surgery. It works by blocking serotonin receptors in the brain and gut, which are involved in triggering the vomiting reflex. This makes it effective in managing acute and delayed nausea associated with cancer treatments. Additionally, it is sometimes prescribed for postoperative nausea and vomiting. Its ability to provide relief with minimal side effects has made it a valuable option in clinical settings.