Zofran reduces the activity of the vagus nerve, which activates the vomiting center in the medulla oblongata, and also blocks serotonin receptors in the chemoreceptor trigger zone. It has little effect on vomiting caused by
motion sickness, and does not have any effect on dopamine receptors or muscarinic receptors.
A 2006 double-blind, randomized controlled trial indicated that ondansetron may have value in the treatment of schizophrenia, as an adjunct to haloperidol.