Irbesartan and Hydrochlorothiazide Association in the Treatment of Hypertension

Abstract

Blood pressure (BP) is one of the most important and common vascular risk factors but it is often poorly controlled. Inhibition of the renin-angiotensin-aldosterone system (RAAS) provides beneficial effects in hypertensives. The association of low-dosed diuretics in combination with RAAS blocking agents allows maximum benefit from potassium depletion and control of compensatory increase in renin secretion, so increasing the efficacy and safety of RAAS blockers. Irbesartan is a potent and selective angiotensin II subtype 1 receptor antagonist indicated for use in patients with hypertension, including those with type 2 diabetes mellitus and nephropathy. Once-daily irbesartan administration provides 24h control of BP. In patients with mild-to-moderate hypertension, irbesartan was as effective as enalapril, atenolol and amlodipine, and more effective than losartan and valsartan in terms of absolute reduction in BP and response rate. Irbesartan also induced regression of left ventricular hypertrophy. Moreover, irbesartan 300 mg/day exerts a significant renoprotective effect in hypertensive type 2 diabetic patients. The relative risk of doubling of serum creatinine was significantly lower with irbesartan than amlodipine or placebo. Irbesartan was also effective in non-diabetic nephropatic patients. Moreover, irbesartan has peroxisome proliferator-activated receptor agonistic effects in in vitro studies, and it also demonstrated beneficial effects on inflammatory markers of atherosclerosis and endothelial function. The overall incidence of adverse events is similar to that of placebo. A fixed dose of hydrochlorothiazide (HCTZ) and irbesartan shows additive antihypertensive effect in a dose dependent manner up to HCTZ 25 mg and irbesartan 300 mg with high tolerability in diverse patient groups. Combination effects on end organ protection must be evaluated by broad spectrum studies. Ongoing trials about irbesartan and its combination with diuretics may provide necessary data to interpret the value of this association among others.

Quantitative Estimation of Anti Hypertension Combination by Ratio Subtraction Spectrophotometry Method

“…Therefore, it is possible to evaluate the clinical efficacy under 2 main titles: BP-lowering efficacy, and the end-organ protection. The combination are fixed-dose combinations achieved BP targets in 77% of patients with systolic, 83% for diastolic and 69% for both BP levels [1], [2], [4], [5], [6], [7]…”

“…Clinically the problem-related side effects may be solved by introducing low-dose combination drugs for first-line antihypertensive therapy. The combination of Irbesartan and Hydrochlorothiazide is one of the right combinations for antihypertensive and effective to reduce blood pressure and oedema in hypertensive patients who are usually accompanied by complications and minimal side effects, namely hyperkalemia [1]. The combined use of angiotensin receptor (AR) blockers and diuretics is better tolerated, but more costly, than generic ACE inhibitors and diuretics, mostly because of the absence of cough and much lower incidence of angioedema [2].…”

“…Finally, IRB-HCT combination brings positive effects of IRB on undesired effects of diuretic, provides advantages of AR blockade, decreases resistance because of activated RAAS, simplifies treatment regimen, besides providing better BP control. Moreover, HCT may increase protective organ benefits of the AR antagonist by providing better BP control in this combination [1], [2], [4], [5], [6], [7].…”

Fixed Doses Combinations Acting on Cardiovascular System - Utilization and Generic Competition

“…It also compensates the increased plasma renin activity provoked by the diuretic [22,23,24,25]. During the observed period FDCs of sartan and diuretic performed steady increase in their dosage forms, trademarks and new international non-proprietary name (INN).…”

Current and Emerging Pharmacotherapies for the Management of Hypertension, Focus on Aliskiren

“…For example irbesartan/HCT combination, proved to be safe, well tolerated and give better patients adherence. [28][29][30] The TALENT study, instead, suggested that nifedipine and telmisartan as monotherapy have a similar effect on blood pressure, but a synergistic effect when taken simultaneously, both on clinical and ambulatory blood pressure. 31,32 Given these positive results, recently fixed combination tablets containing both a calcium channel blocker and an ARB/ACE inhibitor have become available: one combination is enalapril/lercanidipine, this once-daily administration of a fixed-dose enalapril/lercanidipine, by bringing together two distinct and complementary mechanisms of action, reduces BP effectively and has the potential for improved target organ protection relative to either class agent alone.…”