agus nerve, 5-HT agonists such as m-chlorophenylbiguanide have been reported to induce emesis in animals, which is blocked by 5-HT3 antagonists.Granisetron is a selective 5-hydroxytryptamine3(5-HT3) receptor antagonist with little or no affinity for other serotonin receptors, including 5-HT1; 5-HT1A; 5-HT1B/C; 5- HT2; for alpha1-, alpha2-, or beta- adrenoreceptors; for dopamine-D2; or for histamine-H1; benzodiazepine; picrotoxin, or opioid receptors.Animal studies demonstrate that, in binding to 5-HT3 receptors, granisetron blocks serotonin stimulation and subsequent vomiting after emetogenic stimuli such as cisplatin. In the ferret animal model, a single granisetron injection prevented vomiting due to high-dose cisplatin or arrested vomiting within 5 to 30 seconds.In most human studies, granisetron has had little effect on blood pressure, heart rate or ECG. No evidence of an effect on plasma prolactin or aldosterone concentrations has been found in other studies. Another such 5-HT3 antagonist ondansetron has been of particular use in the treatment of post operative nausea and vomiting, it indicates an ability to prevent emesis in the presence of multifactorial aetiologies and interactions with other drugs. The findings display preliminary evidence that prevention of nausea induced by antibiotics and SSRI’s (COSTALL et al. 1997). Other drugs that are similar acting also used in the treatment of nausea from chemotherapy complications is tropisetron. This demonstrates the selectivity that drugs can have and increase the ratio of effective treatment : side effects. ...
