NCIt definition : A carbazole derivative and a selective serotonin receptor antagonist with antiemetic
activity. Palonosetron competitively blocks the action of serotonin at 5-hydroxytryptamine
type 3 (5-HT3) receptors located on vagal afferents in the chemoreceptor trigger zone
(CTZ), resulting in suppression of chemotherapy-induced nausea and vomiting. The CTZ
is located in the area postrema on the dorsal surface of the medulla oblongata at
the caudal end of the fourth ventricle and outside the blood-brain barrier (BBB).;
Alternative definition : NCI-GLOSS: The active ingredient in a drug used to treat nausea and vomiting caused
by cancer treatment. Palonosetron is a type of serotonin receptor antagonist and a
type of antiemetic.;