By Jill Stein
CHICAGO, IL -- May 23, 2007 -- Combining the angiotensin II receptor blocker olmesartan medoxomil and hydrochlorothiazide (HCTZ) increases blood pressure reductions compared with either agent alone, researchers said at the 22nd Annual Meeting of the American Society of Hypertension (ASH).
Luis Miguel Ruilope, MD, associate professor, internal medicine division, Unidad de Hipertension Hospital, Madrid, Spain, and colleagues conducted an integrated analysis of two randomised, double-blind studies with a design that was sufficiently similar to allow pooling of data.
Each study consisted of a 4-week, single-blind, placebo run-in period. At the end of the placebo run-in period, patients with mean diastolic blood pressure measurements greater than or equal to 100 mmHg and less than or equal to 115 mmHg, and with 80% compliance with the study drug regimen, were randomised to one of 12 treatment groups for either 8 or 12 weeks.
Treatment involved olmesartan 0, 10, 20, 40 mg and HCTZ 0, 12.5, and 25 mg in all possible combinations.
The primary efficacy endpoint was the change from baseline in trough sitting diastolic blood pressure at the primary endpoint (week 8 in the first study and week 12 in the second study).
A total of 1,986 patients took at least one dose of the randomised study medication and had at least one post-baseline blood pressure measurement and thus comprised the intent-to-treat population.
Decreases from baseline in seated diastolic blood pressure and seated systolic blood pressure were primarily dose-related with respect to the olmesartan and HCTZ components.
The least squares mean (LSM) differences in mean seated diastolic blood pressure at the end of the trial for olmesartan 20 mg and 40 mg combined with HCTZ 25 mg were -4.0 and -3.6mmHg versus the respective doses of olmesartan alone (both P <.0001). LSM differences in mean seated systolic blood pressure for olmesartan 20 mg and 40 mg combined with HCTZ 25 mg were -8.0 and -6.8 mmHg versus OLM monotherapy (both P <.0001). For both seated diastolic and systolic blood pressures, the effects of olmesartan and HCTZ were additive.
Response surface modeling indicated hat the optimal dose combination to be olmesartan 20 mg to 40 mg and HCTZ 25 mg.
"Reducing the burden of hypertension should be a primary aim of antihypertensive therapy," Dr. Ruilope said in his poster presentation. "However, achieving control of elevated blood pressure is a complex, multi-factorial process that involves primary prevention, early detection, and appropriate treatment to prevent complications. As such, there are patients who fail to respond sufficiently to antihypertensive monotherapy, and these patients have a clinical need for effective and well-tolerated combination therapies."
The study was sponsored by Daiichi-Sankyo.
[Presentation Title: Combined Analysis of the Efficacy of Olmesartan/Hydrochlorothiazide. Abstract P-86]
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