An evaluation of the latest evidence relating to renin-angiotensin system inhibitors

Combination therapy in the treatment of hypertension

Hypertension is a major preventable risk factor for atherosclerosis and ischemic heart disease. Although modern and effective antihypertensive drugs are available, most patients remain with a suboptimal blood pressure control. Most hypertensive patients will need a combination of antihypertensive agents to achieve the therapeutic goals – recent guidelines recommend initiating treatment with two drugs in those patients with a systolic blood pressure >20 mmHg and/or a diastolic blood pressure >10 mmHg above the goals, and in those patients with high cardiovascular risk. In addition, approximately 25% of patients will require three antihypertensive agents to achieve the therapeutic targets. In this review, we analyse the latest information available regarding the treatment of hypertension with combination therapy.

The Effect of Perinatal Taurine on Adult Renal Function Does Not Appear to Be Mediated by Taurine's Inhibition of the Renin-Angiotensin System

This study tests the hypothesis that perinatal taurine supplementation alters adult renal function by inhibition of the renin-angiotensin system. Female Sprague-Dawley rats were fed normal rat chow and given water alone (Control) or water containing an angiotensin converting enzyme inhibitor (captopril, 400 mg/ml) from conception until delivery (FD) or from delivery until weaning (LD). After weaning, the rats received normal rat chow and tap water. At 7–8 weeks of age, renal function at rest and after acute saline load was studied in conscious, restrained male rats. Body weight, mean arterial pressure, heart rate, effective renal blood flow, and renal vascular resistance were not significantly different among the three groups. Compared to Control, glomerular filtration rate, but not filtration fraction, significantly increased after saline load in both FD and LD groups. Water excretion significantly increased only in FD compared to Control, while fractional water excretion was significantly increased after saline load in both FD and LD groups. Sodium excretion significantly increased after saline load only in FD, while both captopril-treated groups significantly decreased fractional sodium excretion. Potassium excretion significantly increased in both FD and LD groups, while fractional potassium excretion significantly increased at rest in FD and decreased in LD groups after saline load. These effects of perinatal RAS inhibition on adult renal function contrast sharply, and are opposite in many cases to, the effects of perinatal taurine supplementation. Thus, these data suggest that perinatal taurine supplementation does not alter adult renal function through its ability to inhibit the perinatal RAS.

Azilsartan medoxomil in the treatment of hypertension: the definitive angiotensin receptor blocker?

INTRODUCTION

Azilsartan medoxomil is the newest angiotensin receptor blocker marketed for the treatment of arterial hypertension. The aim of this article was to review the available evidence about this drug alone or combined with other antihypertensive agents in the treatment of hypertensive population.

AREAS COVERED

For this purpose, a search on MEDLINE and EMBASE databases was performed. The MEDLINE and EMBASE search included both medical subject headings (MeSHs) and keywords including azilsartan or azilsartan medoxomil or angiotensin receptor blockers or renin angiotensin system or chlorthalidone and hypertension. References of the retrieved articles were also screened for additional studies. There were no language restrictions.

EXPERT OPINION

Azilsartan medoxomil has a potent and persistent ability to inhibit binding of angiotensin II to AT1 receptors, which may play a role in its superior blood pressure (BP) -lowering efficacy compared with other drugs, including ramipril, candesartan, valsartan or olmesartan, without an increase of side effects. Chlortalidone is a diuretic which significantly differs from other classic thiazides and has largely demonstrated clinical benefits in outcome trials. The fixed-dose combination of azilsartan and chlorthalidone has been shown to be more effective than other potent combinations of angiotensin receptor blockers plus hydrochlorothiazide, with a good tolerability profile.