Ondansetron, a generic medication is marketed under the following brand names Zofran, Zofran ODT, Zuplenz. Ondansetron belongs to a class of drugs known as 5HT3 receptor antagonist medications. Ondansetron is used in medicine as prevention of vomiting and nausea that may result from cancer medication or surgery. Ondansetron mainly functions by blocking the release of chemicals that cause nausea and vomiting. Ondansetron is a serotonin 5-HT3 receptor blocker that is used alone or with other medications to prevent vomiting and nausea associated with chemotherapy and radiation therapy. This medication can also be used to treat and prevent vomiting and nausea after surgery. Before you receive any dental or medical care, surgery, or emergency care, let your healthcare provider know that you are taking Ondansetron. Ondansetron works by blocking chemical thought to cause vomiting and nausea situations such as chemotherapy. This drug is dissolved on top of the tongue so do not swallow or chew it like other tablet forms.