Angiotensin II receptor antagonists (AIIRAs) are a recently developed class of antihypertensive agents that have gained widespread use in clinical practice. The first available AlIRA, losartan, subsequent agents of this class including candesartan, irbesartan, and telmisartan, may have greater blood pressure (BP) lowering ability. Little information, however, is available on the comparative antihypertensive efficacy among the newer AIIRAS .The present study addressed this question by comparing two agents for which a greater angiotensin II antagonistic and BP-lowering effect has been demonstrated compared with irbesartan and valsartan. Antihypertensive efficacy in the current analysis was assessed by BP measurements in the physician's office, at home, and by ambulatory monitoring to base results on multiple data collected in different environmental conditions.
Subjects were males and females aged between 18 and 75 years old with mild-to-moderate essential hypertension (defined as seated diastolic blood pressure (DBF) between 95 mmHg and 11OmmHg). Subjects were enrolled from 5 sites in Asser region (Appendix 1).
This randomized, multicenter, double blind. parallel-group study compared the antihypertensive efficacy of irbesartan 150 mg with that of valsartan 80 mg, administered once daily for eight weeks The primary objective was to compare the change from baseline in diastolic ABP at trough after eight weeks of treatment Secondary objectives included comparing the changes from baseline in systolic ABP at trough, 24-h mean systolic and diastolic ABP; morning mean and evening mean systolic and diastolic ABP: self-measured DBP and systolic blood pressure (SBP); and office-measured seated DBP and SBP and heart rate at trough. Another secondary objective was to determine the percentage of subjects whose office-measured BP at trough was normalized (DBP 90 mmHg) and who responded to therapy (i.e. whose office-measured DBP was normalized or changed from baseline≥10 mmHg). While both irbesartan and valsartan significantly reduced BP from baseline. in the 303 subjects included in the efficacy analysis for the study's primary objective, irbesartan produced a statistically greater reduction in mean diastolic ABP at trough (-6.73 mmHg vs. -4.84mmHg, respectively: p-0.035). Irbesartan also produced a statistically greater reduction in mean systolic ABP at trough (-11.62 mmHg vs.-7.5 mmHg, respectively; p < 0.01). In addition, irbesartan caused a significantly greater reduction compared with valsartan in mean 24-h diastolic and systolic ABP (p = 0.023 and p < 0.01, respectively), mean daytime diastolic and systolic ABP (p= 0.017 and/)- 0.02, respectively): and mean morning self-measured DBP and SBP (p < 0.01 for both).