Abstract：Objective To explore the influence of seasonal variation on antihypertensive effects of amlodipine besylate tablets and felodipine extended-release tablets.Methods One hundred patients with mild to moderate hypertension were treated with oral felodipine extended-release tablets(group F,n=50) or amlodipine besylate tablets(group A,n=50) 5 mg once daily.Ambulatory blood pressure monitoring(ABPM) was performed once in summer and once in winter and plasma concentrations of nitric oxide(NO) were detected in both groups.Results After treatment,the 24 hour-blood pressure(24 h SBP),daytime systolic blood pressure(dSBP) and nighttime systolic blood pressure(nSBP) in winter were significantly higher than those in summer in both groups(all P<0.05).The difference values for 24 h SBP,dSBP and nSBP between winter and summer in group F[(10.9±4.8),(12.6±4.9) and(9.6±3.6)mmHg,respectively]were larger than those in group A[(5.2±2.9),(5.3±3.1) and(5.1±2.9)mmHg,respectively](all P<0.05).Furthermore,the mean values for 24 h SBP,dSBP,nSBP,24 h SBPSD,dSBPSD and nSBPSD in winter in group F were higher than those in group A(all P<0.05).The morning blood pressure surge was(34.6±10.1) mmHg in winter and(34.3±8.9) mmHg in summer in group A and(38.8±11.3) mmHg and(36.1±9.8) mmHg in group F,and differences were significant(all P<0.01).The standard-eaching rates of 24 h SBP,dSBP and nSBP ABPM in group A(78.6%,76.5% and 78.6%,respectively) were higher than those in group F(53.7%,58.5% and 46.3%,respectively)(all P<0.01).Moreover,plasma concentrations of NO were(57.32±10.37) μmol·L-1 in winter and(64.26±11.62) μmol·L-1in summer in group A and(48.74±12.10)μmol·L-1and(55.21±9.86)μmol·L-1in group F,and differences were significant(all P<0.05).Conclusion Amlodipine besylate tablets for blood pressure have smaller seasonal differences,better stability and higher standard-reaching rates and provide better protection for vascular endothelial function than felodipine extended-release tablets.
2012, Vol. 52 
