Kytril uses are primarily focused on the prevention of nausea and vomiting in people who are about to undergo radiation or chemotherapy. An injectable form of the drug can also be used in people who are about to have surgery or chemotherapy. Kytril is not approved for use in children. Healthcare providers may occasionally recommend Kytril "off-label" for preventing nausea and vomiting associated with other causes.
Kytril® (granisetron hydrochloride) is a prescription medication approved for the prevention of nausea and vomiting due to chemotherapy or radiation. An injectable form of Kytril is also available and is used to prevent nausea and vomiting due to chemotherapy or surgery.
Nausea and vomiting are common side effects of chemotherapy and radiation (see Chemotherapy and Nausea). Nausea and vomiting from chemotherapy or radiation are likely due to many causes. Some types of chemotherapy or radiation are more likely to cause nausea and vomiting than others. Radiation to the entire body (known as total body irradiation) and radiation to the abdomen are very likely to cause nausea and vomiting.
In general, Kytril is better at preventing vomiting than preventing nausea. It is also much easier to prevent nausea and vomiting than to treat it once it starts. Kytril is licensed to prevent nausea and vomiting, but it is not a treatment for vomiting or nausea.
Nausea and vomiting are complex processes involving many chemicals in the body and several parts of the body, including the brain and the small intestine. It is likely that Kytril works in the small intestine, but it may also work in the brain.
Kytril works by blocking serotonin, a chemical produced by the body that is associated with nausea and vomiting. Serotonin has many effects in the body and has several receptors where it can bind. Kytril blocks serotonin at a specific type of receptor (the 5-HT3 receptor), which is important for nausea and vomiting. It has no effects on other types of serotonin receptors in the body.