For the prevention of nausea and vomiting associated with emetogenic cancer chemotherapy, postoperation, and radiation. Also used for the treatment of postoperative nausea and vomiting.
Ondansetron is a selective serotonin 5-HT<sub>3</sub> receptor antagonist. The antiemetic activity of the drug is brought about through the inhibition of 5-HT<sub>3</sub> receptors present both centrally (medullary chemoreceptor zone) and peripherally (GI tract). This inhibition of 5-HT<sub>3</sub> receptors in turn inhibits the visceral afferent stimulation of the vomiting center, likely indirectly at the level of the area postrema, as well as through direct inhibition of serotonin activity within the area postrema and the chemoreceptor trigger zone.
Low blood pressure and fainting, sudden blindness, severe constipation
Ondansetron is well absorbed after oral administration and undergoes limited first-pass metabolism.
5.7 hours
* 0.38 L/h/kg [Normal Adult Volunteers (19-40 yrs)] * 0.32 L/h/kg [Normal Adult Volunteers (61-74 yrs)] * 0.26 L/h/kg [Normal Adult Volunteers (>=75 yrs)]