I take 8 mg every 8 hours, usually about an hour before I take my meds. You will need a prescription for it. With
Zofran, do not wait until you get nauseated.
Ondansetron works by blocking the 5HT3 receptors that are found in the brain and gut. This prevents the nausea messages being sent from these areas to the vomiting centre. Ondansetron therefore prevents nausea, retching and vomiting that can otherwise occur following surgery or due to cancer treatments.
http://www.netdoctor.co.