药效学研究是对药物进行有效性评价，目的在于阐明药物防治和诊断疾病的机理，为开发和评价药物提供科学依据。

药效学研究的给药方法：预防性给药、治疗性给药、防治结合的给药方式 选用一种以上动物进行药效试验，每一方面药理作用要选用2~3种动物模型或者细胞模型来做。

Droxytryptamine (5-HT; serotonin) 5-HT3 receptor is an excitatory ligandgated ion channel expressed in for example the brain and the gastrointestinal tract. CSTI-300 as a selective, high affinity 5-HT3 receptor partial agonist. CSTI-300 was examined alongside the selective 5-HT3 receptor antagonist alosetron (which is also currently marketed as a therapeutic for IBS-d). Sub-cutaneous application of 5-hydroxytryptophan (5-HTP; 10 mg/kg) markedly increased the rat’s sensitivity to abdominal contractions. CSTI-300 and Alosetron displayed similar efficacy in a rodent in vivo model of IBS-d, measured by a reduction in colonic sensitivity. The experiments (Rat colon distension model of IBS-d) were carried out by Medicilon. The protocol complied with and was approved by the Institutional Animal Care and Use Committee and Medicilon is accredited by the NIH Office of laboratory Animal Welfare (OLAW) and AAALAC. Experiments (dog behavioural and emesis model) were performed by Medicilon. The protocol for the dog behavioural and emesis model complied with and was approved by the Institutional Animal Care and Use Committee.