Research and application of antiemetics in tumor therapy

The mechanism of emetic and the transitive neurotransmitter and the therapeutic drugs are diversity,and the same kind drugs have different characteristics.The neurotransmitters of emetic are included:dopamine,acetylcholine,histamine,5-hydroxytryptamine,neurokinin.The mainly drugs used in clinical are 5-hydroxytryptamine-3(5-HT3)serotonin receptor antagonists and neurokinin-1 receptor antagonist.The mechanism of 5-HT3 antagonists are similar,their differences are the mode of action and affinity with receptors,the potency and pharmaceutical characteristics.Aprepitant is the first NK1 receptor antagonist approved by FDA.The three-drug combination of 5-HT3 serotonin receptor antagonist,dexamethasone and aprepitant are recommended before chemotherapy of high emetic risk.American Society of Clinical Oncology Guideline for Antiemetics in Oncology was updated in 2006.According to the guideline,the antiemetic agents are divided into three kinds:1)highest therapeutic index drugs;2)lower therapeutic index drugs;3)adjunctive drugs.For patients with high or moderate emetic risk,the three-drug combination is recommended.For patients with low emetic risk,the adjunctive drugs can be used.