helps to relieve nausea and vomiting, especially when
associated with the treatment of cancer (chemotherapy).
Ondansetron may also be used to prevent or treat nausea
and vomiting that occurs after surgery, and occasionally
is used to treat severe vomiting during pregnancy.
is a competitive, highly selective antagonist of
5-hydroxytryptamine (serotonin) subtype 3 (5-HT 3)
receptors. 5-HT 3 receptors are present
peripherally on vagal nerve terminals centrally in the
area postrema of the brain. It is not certain whether
ondansetron's action is mediated peripherally,
centrally, or both. Cytotoxic drugs and radiation appear
to damage gastrointestinal mucosa, causing the release
of serotonin from the enterochromaffin cells of the
gastrointestinal tract. Stimulation of 5-HT 3
receptors causes transmission of sensory signals to the
vomiting center via vagal afferent fibers to induce
vomiting. By binding to 5-HT 3 receptors,
ondansetron blocks vomiting mediated by serotonin
Ondansetron has no dopamine-receptor antagonist
the physician’s advice.
: 2 ml