Granisetron Injection immediate-release injection is used to prevent nausea and vomiting caused by cancer chemotherapy and to prevent and treat nausea and vomiting that may occur after surgery. Granisetron extended-release (long-acting) is used with other medications to prevent nausea and vomiting caused by cancer chemotherapy that may occur immediately or several days after receiving chemotherapy medications. Granisetron is in a class of medications called 5-HT3 receptor antagonists. It works by blocking serotonin, a natural substance in the body that causes nausea and vomiting.
Granisetron immediate-release injection comes as a solution (liquid) to be injected intravenously (into a vein) and granisetron extended-release comes as a liquid to be injected subcutaneously (under the skin). To prevent nausea and vomiting caused by cancer chemotherapy, granisetron immediate-release and extended-release injection(s) are usually given by a healthcare provider in a hospital or clinic within 30 minutes before the start of chemotherapy. To prevent nausea and vomiting caused by surgery, granisetron immediate-release is usually given during surgery. To treat nausea and vomiting caused by surgery, granisetron is given as soon as nausea and vomiting occur.