Vardenafil (Levitra) is an oral therapy for the treatment of erectile dysfunction. It is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). Penile erection is a hemodynamic process initiated by the relaxation of smooth muscle in the corpus cavernosum and its associated arterioles. During sexual stimulation, nitric oxide is released from nerve endings and endothelial cells in the corpus cavernosum. Nitric oxide activates the enzyme guanylate cyclase resulting in increased synthesis of cyclic guanosine monophosphate (cGMP) in the smooth muscle cells of the corpus cavernosum. The cGMP in turn triggers smooth muscle relaxation, allowing increased blood flow into the penis, resulting in erection. The tissue concentration of cGMP is regulated by both the rates of synthesis and degradation via phosphodiesterases (PDEs). The most abundant PDE in the human corpus cavernosum is the cGMPspecific phosphodiesterase type 5 (PDE5); therefore, the inhibition of PDE5 enhances erectile function by increasing the amount of cGMP.
盐酸瓦地那非三水合物制备储备液:
浓度溶解体积质量
1mg
5mg
10mg
1mM
2.1032mL
10.5159mL
21.0318mL
5mM
0.4206mL
2.1032mL
4.2064mL
10mM
0.2103mL
1.0516mL
2.1032mL
50mM
0.0421mL
0.2103mL
0.4206mL
盐酸瓦地那非三水合物临床数据( 数据源于:http:// clinicaltrials.gov)
Conversion of different model animals based on BSA(Value based on data from FDA Draft Guidelines)
Animal A (mg/kg)=Animal B(mg/kg)multiplied by AnimalBm系数/AnimalAm系数 For example, to modify the dose of resveratrol uesd for a mouse(22.4mg/kg) to a dose based on the BSA for a rat, multiply 22.4mg/kg by the Km factor for a mouse and zhen divide by the Km factor for a rat. This calculation results in a rat equivalent dose for resveratrol of 11.2mg/kg