What Is Ondansetron (Zofran)?

When To Take Doses

Patients undergoing chemotherapy typically take one dose approximately thirty minutes before each chemotherapy session. Individuals who use ondansetron during radiation treatment are often advised to take a dose one to two hours before their appointment. When used before surgery, patients usually take it one hour before their operation. An adult dose can range from sixteen to twenty-four milligrams. Patients should read the medication label carefully before taking ondansetron. At times, patients might be asked to take their very first dose of this medicine at a clinic so they can be monitored by medical staff. The intravenous solution of ondansetron must be administered at a hospital or in a clinical setting, and patients usually receive the first dose as an infusion over a fifteen-minute period. The dose is based on the patient's weight, and doctors usually start with a dose of 0.15 milligrams per kilogram of body weight. The maximum dose for the intravenous solution is sixteen milligrams.