Objective:To investigate effect of Shuangdan drop pills (SDP) on blood pressure and plasma angiotensin Ⅱ (AngⅡ) expression in patients with essential hypertension (EH) and to evaluate its safety. Method: Retrospective analysis from February 2009 to December 2011 for EH patients admitted with blood stasis syndrome were carried out in a sample of 200 cases. Methods of randomized

double-blind

double simulation

positive drug parallel control method were employed to divide the sample into treatment group and control group(1∶1

100 cases each). The treatment group was given SDP 20 pills

tid

po; the control group was taken 10 mg enalaprilat

5 weeks for one course of treatment. Before and after treatment

dynamic blood pressure (ABPM) check and safety indexes (three conventional and liver

kidney) detection were carried out 24 h respectively.Radioimmunoassay was employed to measure plasma AngⅡ level in two groups before and after treatment. Result: In two groups

mean blood pressure during 24 h

daytime blood pressure mean

night blood pressure mean showed significant difference before and after treatment (P<0.05); no significant difference was found between the two groups. The pressure fluctuation in two groups before and after treatment was significantly decreased (P<0.05); and the treatment group was better than the controls (P<0.05). In the two groups

plasma AngⅡ was significantly lowered after treatment (P<0.05)

and the effect in treatment group was better than the controls (P<0.05). Conclusion: SDP has a good stable decompression effect

which is comparable to enalaprilat. SDP can effectively reduce the serum AngⅡ level in EH patients

with effect better than enalaprilat.