Comparison of angiotensin II type 1 receptor antagonists in the treatment of essential hypertension

Comparison of effects of telmisartan versus valsartan on post-induction hypotension during noncardiac surgery: a prospective observational study

BACKGROUND

Telmisartan is considered more potent than valsartan. Hemodynamic response during anesthesia induction may be influenced by anti-hypertension (HTN) medication. The present study compared the effect of anti-HTN medications on post-induction hypotension during noncardiac surgeries.

METHODS

This observational study standardized the anesthetic regimen across patients, with hypotension defined as mean blood pressure (BP) of less than 65 mmHg. The hemodynamic changes within 5 min before and after endotracheal intubation, and within 10 min before and after surgical incision were measured. Transthoracic echocardiographic evaluation of the left ventricle (LV) during anesthesia induction was performed. The primary endpoint was the decline in mean BP after anesthetic administration in telmisartan and valsartan groups. Multivariate logistic regression analysis was used to identify predictors of post-induction hypotension.

RESULTS

Data from 157 patients undergoing noncardiac surgery were analyzed. No significant differences were found in mean BP decline between the two groups during anesthesia induction. Hemodynamic changes and LV ejection fraction (EF) during anesthesia induction were similar between the groups. Age and preoperative initial mean BP in operation room (OR) were associated with post-induction hypotension in both groups.

CONCLUSIONS

The angiotensin receptor blocker (ARB) type did not influence post-induction hypotension during anesthesia induction. Age and preoperative initial mean BP in OR were associated with post-induction hypotension in patients taking ARBs.

Mixed Pluronic/lecithin micelles formulation for oral bioavailability of candesartan cilexetil drug: in vitro characterization and in vivo pharmacokinetic investigations

OBJECTIVE

This study aimed to develop a mixed polymeric micelle formulation incorporating candesartan cilexetil (CAND) drug to enhance its oral bioavailability for the better treatment of hypertension.

METHODS

A Box-Behnken design was utilized to optimize the CAND-incorporated mixed polymeric micelles formulation (CAND-PFLC) consisting of Pluronics (P123 and F68) and lecithin (LC). The optimized CAND-PFLC micelles formulation was characterized for size, shape, zeta potential, polydispersity index (PDI), and entrapment efficiency (%EE). An in vitro release study, ex vivo permeability investigation, and an in vivo pharmacokinetic analysis were carried out to evaluate the performance of the formulation.

RESULTS

The optimized CAND-PFLC micelles formulation demonstrated a spherical shape, a particle size of 44 ± 2.03 nm, a zeta potential of -7.07 ± 1.39 mV, a PDI of 0.326 ± 0.06, and an entrapment efficiency of 87 ± 3.12%. The formulation exhibited excellent compatibility, better stability, and a noncrystalline nature. An in vitro release study revealed a faster drug release of 7.98% at gastric pH in 2 hrs and 94.45% at intestinal pH within 24 hrs. The ex vivo investigation demonstrated a significantly enhanced permeability of CAND, with 94.86% in the micelle formulation compared to 9.03% of the pure drug. In vivo pharmacokinetic analysis showed a 4.11-fold increase in oral bioavailability of CAND compared to the marketed formulation.

CONCLUSION

The CAND-PFLC mixed micelle formulation demonstrated improved performance compared to pure CAND, indicating its potential as a promising oral drug delivery system for the effective treatment of hypertension.

Angiotensin II Induces Increased Myocardial Expression of Receptor for Advanced Glycation End Products, Monocyte/Macrophage Infiltration and Circulating Endothelin-1 in Rats With Experimental Diabetes

OBJECTIVES

It is known that the receptor for advanced glycation end products (RAGE) activation is involved in the pathogenesis of cardiovascular disease in diabetes. Previous studies have shown the presence of angiotensin II (Ang II) in diabetes, suggesting a role for this hormone during the disease. However, the association between RAGE and Ang II during pathologic cardiac remodelling after streptozotocin (STZ)-induced diabetes remains unclear. Because Ang II is capable of inducing pro-inflammatory events, blocking its production (enalapril), and its action on its receptor (losartan) could decrease inflammatory events in the myocardium in this experimental model of diabetes. Thus, the aim of this study was to assess the association between RAGE expression, inflammatory events and Ang II in the myocardium during STZ-induced diabetes.

METHODS

Diabetes was induced by intravenous injection of STZ in Sprague-Dawley rats. Myocardial expressions of RAGE, monocyte/macrophage (ED-1-positive cells) infiltration and the intercellular adhesion molecule-1 were determined by histochemical methods. Levels of circulating endothelin-1 (ET-1) were determined by enzyme-linked immunoassay. Effects of Ang II included blocking using losartan (15 mg/kg body weight per day by gastric gavage) or enalapril (18 mg/kg body weight per day by gastric gavage).

RESULTS

Increased expression of both RAGE and ED-1 was seen in the myocardium, but expression of myocardial vascular intercellular adhesion molecule-1 remained unchanged. Circulating levels of ET-1 in STZ rats were increased. Renin‒angiotensin system inhibition decreased expression of myocardial RAGE, ED-1 and ET-1.

CONCLUSIONS

The present findings suggest a role for Ang II in myocardial inflammation in STZ-induced diabetes mediated by RAGE and ET-1.

Effect of Fimasartan versus Valsartan and Olmesartan on Office and Ambulatory Blood Pressure in Korean Patients with Mild-to-Moderate Essential Hypertension: A Randomized, Double-Blind, Active Control, Three-Parallel Group, Forced Titration, Multicenter, Phase IV Study (Fimasartan Achieving Systolic Blood Pressure Target (FAST) Study)

Purpose

Head-to-head comparison of the blood pressure (BP) lowering effect of fimasartan versus valsartan, with olmesartan as a reference, on office blood pressure and ambulatory BP.

Patients and Methods

Of the 369 randomly assigned patients in this study, 365 hypertensive patients were referred as the full analysis set and divided into 3 groups with a 3:3:1 ratio (fimasartan group: 155, valsartan group: 157, olmesartan group: 53). After the 2-week single-blind placebo run-in period, initial standard doses of 60-mg fimasartan, 80-mg valsartan, and 10-mg olmesartan were administered for 2 weeks, then forcibly up-titrated higher doses (fimasartan 120 mg, valsartan 160 mg, olmesartan 20 mg) were given for 4 weeks. ABP was measured before and after the 6-week treatment. Primary endpoint was reduction of sitting office systolic BP (SiSBP) of fimasartan compared to valsartan after 6 weeks. Secondary endpoints were reduction of sitting office diastolic BP (SiDBP) and 24 hrs, day-time, and night-time mean systolic and diastolic ABP (ASBP, ADBP) after 6 weeks.

Results

Patients’ mean age was 58.34±7.68 years, and 289 patients were male (79.18%). After the 6-week treatment, SiSBP reduction of fimasartan and valsartan were −16.26±15.07 and −12.81±13.87 (p=0.0298) and SiDBP were −7.63±9.67 and −5.14±8.52 (p=0.0211). Reductions in 24 hrs mean ASBP were −15.22±13.33 and −9.45±12.37 (p=0.0009), and ADBPs were −8.74±7.55 and −5.98±7.85 (p=0.0140). Reductions of night-time ASBPs were −16.80±15.81 and −10.32±14.88 (p=0.0012), and those of night-time ADBPs were −8.89±9.93 and −5.55±9.70 (p=0.0152). Reduction of BP in olmesartan group did not demonstrate significant difference with fimasartan group in all end-points.

Conclusion

Fimasartan 120-mg treatment demonstrated superior efficacy in reduction of SiSBP, SiDBP, and 24 hrs ASBP and ADBP compared to valsartan 160 mg. Reduction of night-time ASBP from baseline was largest in fimasartan group, suggesting that fimasartan may be effective for recovering dipping pattern.

NCT number

NCT02495324 (Fimasartan Achieving SBP Target (FAST) study).

Use of olmesartan and enteropathy outcomes: a multi-database study

BACKGROUND

Multiple case reports suggest that olmesartan may be linked to sprue-like enteropathy; however, few epidemiological studies have examined this association and results have been mixed.

AIM

To assess whether olmesartan is associated with a higher rate of enteropathy vs other angiotensin II receptor blockers (ARBs).

METHODS

We conducted a cohort study among ARB initiators in 5 US claims databases representing different health insurance programmes. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for enteropathy-related outcomes, including coeliac disease, malabsorption, concomitant diagnoses of diarrhoea and weight loss, and non-infectious enteropathy, comparing olmesartan initiators to initiators of other ARBs after propensity score (PS) matching.

RESULTS

We identified 1 928 469 eligible patients. The unadjusted incidence rates were 0.82, 1.41, 1.66 and 29.20 per 1000 person-years for coeliac disease, malabsorption, concomitant diagnoses of diarrhoea and weight loss, and non-infectious enteropathy respectively. HRs after PS matching comparing olmesartan to other ARBs were 1.21 (95% CI, 1.05-1.40), 1.00 (95% CI, 0.88-1.13), 1.22 (95% CI, 1.10-1.36) and 1.04 (95% CI, 1.01-1.07) for each outcome. HRs were larger for patients aged 65 years and older (eg for coeliac disease, 1.57 [95% CI, 1.20-2.05]), for patients receiving treatment for more than 1 year (1.62 [95% CI, 1.24-2.12]), and for patients receiving higher cumulative olmesartan doses (1.78 [95% CI, 1.33-2.37]).

CONCLUSIONS

This large-scale, multi-database study found a higher rate of enteropathy in olmesartan initiators as compared to initiators of other ARBs, although the absolute incidence rate was low in both groups.

Single-Center Evaluation of the Pharmacokinetics and Safety of the Angiotensin II Receptor Antagonist Azilsartan Medoxomil in Mild to Moderate Hepatic Impairment

Azilsartan medoxomil (AZL‐M) is a potent angiotensin II receptor blocker that decreases blood pressure in a dose‐dependent manner. It is a prodrug that is not detected in blood after its oral administration because of its rapid hydrolysis to the active moiety, azilsartan (AZL). AZL undergoes further metabolism to the major metabolite, M‐II, and minor metabolites. The objective of this study was to determine the effect of mild to moderate hepatic impairment on the pharmacokinetics of AZL and its major metabolite. This was a single‐center, open‐label, phase 1 parallel‐group study that examined the single‐dose (day 1) and multiple‐dose (days 4–8) — 40 mg — pharmacokinetics of AZL and M‐II in 16 subjects with mild and moderate hepatic impairment by Child‐Pugh classification (n = 8 per group) and subjects (n = 16) matched based on age, sex, race, weight, and smoking status. Mild or moderate hepatic impairment did not cause clinically meaningful increases in exposure to AZL and M‐II. Mild or moderate hepatic impairment had no clinically meaningful effect on the plasma protein binding of AZL and M‐II. Single and multiple doses of AZL‐M 40 mg were well tolerated in all subject groups. Based on the pharmacokinetic and tolerability findings, no dose adjustment of AZL‐M is required for subjects with mild and moderate hepatic impairment.

Comparative Efficacy of Angiotensin II Antagonists in Essential Hypertension: Systematic Review and Network Meta-Analysis of Randomised Controlled Trials

BACKGROUND

Evidence on the long-term clinical benefits of individual members of angiotensin II receptor blockers is limited given the lack of head-to-head studies. We conducted a network meta-analysis to determine the comparative efficacy of different members within this drug class with respect to outcomes of (i) blood pressure reduction (at 24 and 52 weeks) and (ii) prevention of cardiovascular disease (>104 weeks).

METHODS

A systematic literature review was conducted - Protocol registration: (PROSPERO - CRD42014007067) - to identify relevant literature from the following databases: Cochrane Library, PubMed, Medline and EMBASE; searched from inception to July 2016. Randomised controlled trials (RCTs) were included if they reported long-term effectiveness relating to blood pressure, mortality, myocardial infarction or stroke. Eligible studies included those with placebo or specific active-treatment comparators (either another angiotensin II receptor blockers or hydrochlorothiazide). A Bayesian random-effects network model was used to combine direct within-trial comparisons between treatment groups with indirect evidence from other trials.

RESULTS

Thirty-six studies were identified, representing 28 unique trials. Blood pressure reduction, based on 12 studies (n=807) with fixed dosing regimen, was found to be similar amongst members of the angiotensin receptor blocker drug class at both 24 and 52 weeks. A network meta-analysis of five studies (n=16,716) with a treat-to-target approach found that prevention of all-cause mortality, stroke and myocardial infarction was similar across the angiotensin-receptor blockers therapies initiated.

CONCLUSIONS

Current evidence is insufficient to show differences in any members within the angiotensin II receptor blocker drug class with respect to blood pressuring lowering effects or a reduction in cardiovascular diseases.

Efficacy of olmesartan amlodipine in Colombian hypertensive patients (soat study)

BACKGROUND

Emerging evidence has shown a significant deficit in the control of hypertension (blood pressure <140/90 mmHg) among Hispanics or Latinos in about 65%. This study aims to determine the efficacy of the combination in fixed doses of olmesartan and amlodipine (20/5, 40/5, and 40/10 mg) in hypertensive patients treated in daily clinical practice by Colombian doctors.

METHODS

This was an observational, retrospective, open-label, multi-center, non-comparative study. The primary outcome was a change in systolic and diastolic blood pressure from the baseline to week 12; the secondary outcome was the proportion of patients achieving a target blood pressure of <140/90 mmHg. Safety and tolerability were also evaluated. For analysis, a student t test was used for paired data, McNemar test, and ANCOVA.

RESULTS

A total of 428 patients were enrolled from 16 centers in Colombia. At 12 weeks, patients' systolic blood pressure decreased in response to all three doses: by 27.75 ± 20.73 mmHg in 20/5 mg, 31.13 ± 22.23 mmHg in 40/5 mg, and 46.96 ± 20.15 mmHg in 40/10 mg (all p < 0.001). Furthermore, the diastolic blood pressure decreased by 14.19 ± 12.89 mmHg in 20/5 mg, 16.25 ± 10.87 mmHg in 40/5 mg, and 24.83 ± 10.41 mmHg in 40/10 mg (all p < 0.001). The percentage of patients achieving target blood pressure was 71.31% in 20/5 mg, 70.16% in 40/5 mg, and 63.33% in 40/10 mg.

CONCLUSIONS

This study demonstrates the efficacy of the combination in fixed doses of olmesartan and amlodipine in the treatment of Colombian hypertensive patients.

Management of Hypertension Using Olmesartan Alone or in Combination

Hypertension is one of the most significant and consistent risk factors for many cardiovascular diseases. The global prevalence of hypertension has dramatically increased over recent years. Life-style and genetic factors are generally considered to be primarily responsible for the incidence of hypertension. Concerning the high morbidity rate, setting up an updated standard for hypertensive patients becomes indispensable. According to the widely accepted standard treatments for hypertension, these four basic principles should be taken into account: low dosage; medication should provide long term-control; combination therapies are becoming common; personalized treatments are a newer approach. In most patients with hypertension, adequate control of BP can be achieved with combined therapy. Therefore, antihypertensive agents with complementary mechanisms are now recommended. In this review, we focus on the pharmacology, antihypertensive efficacy, and adverse events (AEs) of olmesartan medoxomil, either alone or in combination with other antihypertensive medications. In conclusion, olmesartan medoxomil, is an angiotensin II receptor blocker with an excellent efficacy in the reduction and stabilization of blood pressure. When combined with calcium channel blockers (CCBs) and diuretics, olmesartan medoxomil has a better effect on controlling BP and reducing AEs in patients.

The Impact of Azilsartan Medoxomil Treatment (Capsule Formulation) at Doses Ranging From 10 to 80 mg: Significant, Rapid Reductions in Clinic Diastolic and Systolic Blood Pressure

In this phase 2, multicenter, parallel-group, double-blind, dose-ranging study, hypertensive adults (n=449) were randomized to receive one of five doses of a capsule formulation of azilsartan medoxomil (AZL-M; 5, 10, 20, 40, 80 mg), olmesartan medoxomil (OLM) 20 mg, or placebo once daily. The primary endpoint was change in trough clinic diastolic blood pressure (DBP) at week 8. AZL-M provided rapid statistically and clinically significant reductions in DBP and systolic blood pressure (SBP) vs placebo at all doses except 5 mg. Placebo-subtracted changes were greatest with the 40 mg dose (DBP, -5.7 mm Hg; SBP, -12.3 mm Hg). Clinic changes with AZL-M (all doses) were statistically indistinguishable vs OLM, although there were greater reductions with AZL-M 40 mg using 24-hour ambulatory blood pressure. Adverse event frequency was similar in the AZL-M and placebo groups. Based on these and other findings, subsequent trials investigated the commercial AZL-M tablet in the dose range of 20 to 80 mg/d.

Acute eprosartan-induced intrarenal vasodilation in hypertensive humans is not influenced by dietary sodium intake or angiotensin II co-infusion

BACKGROUND

Angiotensin II (Ang II) is thought to play an important role in the development of hypertension. Nevertheless, knowledge on the angiotensin II type-1-receptors (AT1Rs) in the hypertensive kidney and the influence of sodium intake and renin-angiotensin system activity on intrarenal AT1R blockade is scarce. To improve our understanding of renal AT1Rs in hypertensive patients, we studied the effects of acute, local administration of AT1R-blocker eprosartan in kidneys of patients with essential hypertension (off medication).

METHOD

In 73 hypertensive patients who were scheduled for diagnostic renal angiography, we measured renal blood flow (Xenon washout method) before and during intrarenal infusion of two incremental doses of eprosartan (3 and 10 μg/kg/min for 15 min per dose). We hypothesized that the vasodilatory effects of eprosartan would be enhanced by low sodium intake and would be reduced during Ang II co-infusion. Therefore, we allocated the patients to either a high or a low sodium diet and coinfused Ang II (1 ng/kg/min) in a subgroup.

RESULTS

Eprosartan infusion resulted in intrarenal vasodilation in all groups. No differences in the magnitude of this effect were found between the groups. No correlation was found between 24-h urinary sodium excretion (a proxy for dietary sodium intake) and the effect of eprosartan.

CONCLUSION

Eprosartan-induced vasodilation is not influenced by sodium intake and/or co-infusion of Ang II. These rather unexpected findings could be explained by differences between circulating and tissue Ang II levels, variations in AT1R expression, and/or stimulation of other vasodilatory pathways.

Antihypertensive effects of olmesartan compared with other angiotensin receptor blockers: a meta-analysis

OBJECTIVES

Angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) have been shown to be effective and well tolerated in hypertensive patients. Olmesartan is the seventh angiotensin receptor blocker licensed by the US Food and Drug Administration. The aim of this meta-analysis was to determine the efficacy and tolerability of olmesartan medoxomil in comparison with other ARBs.

DATA SOURCES

Reports of randomized controlled trials (RCTs) of olmesartan versus other ARBs were identified through a systematic search of PubMed (up to July 2010), EMBASE (1980 to July 2010), SinoMed (up to July 2010), and the Cochrane Central Register of Controlled Trials (Cochrane Library Issue 7, 2010).

REVIEW METHODS

Pertinent studies were selected through extensive searches of PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and SinoMed. Two of the authors abstracted data from the identified studies independently. Criteria for inclusion in our meta-analyses were randomized clinical trials in which patients were receiving an ARB and outcome data for blood pressure reduction or the incidence of adverse events were available. Quantitative and qualitative analyses of data from all RCTs meeting the criteria were performed. Our meta-analysis was undertaken according to the Quality of Reporting Meta-analyses (QUOROM) statement.

RESULTS

Twenty-two studies with data from 4892 patients were considered for analyses. Olmesartan provided greater diastolic blood pressure (DBP) and systolic blood pressure (SBP) reductions compared with losartan (DBP: 95% confidence interval [CI] 0.59, 2.62; SBP: 95% CI 0.46, 5.92). Olmesartan provided greater SBP reductions compared with valsartan (95% CI 0.29, 3.16). Similar blood pressure response rates and incidence of adverse events were found with losartan, valsartan, candesartan, and irbesartan.

CONCLUSION

Olmesartan provides better antihypertensive efficacy than losartan and valsartan and has no association with an increased risk of adverse events in comparison with losartan, valsartan, candesartan, and irbesartan.

Comparative effectiveness analysis of amlodipine/renin-angiotensin system blocker combinations

A comparative effectiveness analysis of antihypertensive therapy amlodipine (AML) and angiotensin receptor blocker (ARB) fixed- and loose-dose combinations (FDCs and LDCs) in achieving blood pressure (BP) reduction and Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC 7) goal attainment was made using retrospective electronic medical record (EMR) data. Treatment goal rates ranged from 35.0% for LDC AML/losartan to 45.7% for FDC AML/olmesartan (OM). FDC AML/OM achieved significantly greater reductions in systolic BP than FDC AML/benazepril (BEN), FDC AML/valsartan (VAL), and LDC AML/ARBs, respectively, and significantly greater reductions in diastolic BP than FDC AML/VAL and LDC therapy, respectively. Compared with patients treated with AML/OM, patients prescribed AML/VAL and LDC AML/ARB were significantly less likely to attain JNC 7 BP goal. Among subpopulations, AML/OM yielded higher rates of goal attainment among both African Americans and obese/overweight patients relative to AML/VAL and combined LDCs. Switchers from monotherapy with AML, OM, or VAL to AML/OM were significantly more likely to attain JNC 7 goals than those switching to AML/VAL or AML/BEN.

Efficacy/safety of olmesartan medoxomil versus losartan potassium in naïve versus previously treated subjects with hypertension

INTRODUCTION

A predefined exploratory analysis of a prospective, randomized, double-blind, forced-titration study of olmesartan medoxomil (OM) versus losartan potassium (LOS) in subjects with hypertension not previously or previously treated with antihypertensive medication is reported.

METHODS

The study included a 3-4-week placebo run-in and an 8-week active treatment period: OM (weeks 1-4, OM 20 mg; weeks 5-8, OM 40 mg); placebo + OM (weeks 1-2, placebo; weeks 3-4, OM 20 mg; weeks 5-8, OM 40 mg); and LOS (weeks 1-4, LOS 50 mg; weeks 5-8, LOS 100 mg). Analyses focused on comparison of OM and placebo + OM combined versus LOS. Efficacy endpoints were mean change from baseline in seated cuff diastolic blood pressure (SeDBP) at week 8 (primary); seated cuff systolic blood pressure (SeSBP) at weeks 4 and 8, and SeDBP at week 4 (secondary), and BP target achievement (tertiary).

RESULTS

The randomized population (n = 941) had a mean ± SD age of 51.9 ± 9.7 years, 54.5% were male, and 20.1% were naïve to antihypertensive medication. For treatmentnaïve subjects, baseline seated BP (SeBP) (±SD) was 157.4 (±10.9)/101.8 (±4.3) mmHg with OM and 156.3 (±10.8)/101.1 (±3.9) mmHg with LOS, while non-naïve subjects had 158.4 (±10.2)/100.9 (±4.0) mmHg with OM and 158.8 (±10.1)/101.3 (±4.2) mmHg with LOS. OM monotherapy produced significantly greater changes in least-squares mean (±SE) SeDBP compared with LOS in both treatment-naïve (-9.7 [1.0] vs. -6.6 [1.0] mmHg; P = 0.0232 vs. LOS) and non-naïve subjects (-9.6 [0.5] vs. -7.3 [0.5] mmHg; P = 0.0013 vs. LOS). A significantly greater proportion of patients achieved the SeBP goal of <140/90 mmHg with OM compared with LOS in treatment-naïve (34.1% vs. 19.0%, respectively; P = 0.0109) and non-naïve subjects (31.0% vs. 19.6%; P = 0.0008).

CONCLUSION

Overall, OM monotherapy resulted in significantly greater SeBP reductions and greater SeBP goal achievement than LOS, irrespective of previous medication use. Both OM and LOS therapy were well tolerated.

Angiotensin receptor blockers for heart failure

BACKGROUND

Chronic heart failure (HF) is a prevalent world-wide. Angiotensin receptor blockers (ARBs) are widely prescribed for chronic HF although their role is controversial.

OBJECTIVES

To assess the benefit and harm of ARBs compared with ACE inhibitors (ACEIs) or placebo on mortality, morbidity and withdrawals due to adverse effects in patients with symptomatic HF and left ventricular systolic dysfunction or preserved systolic function.

SEARCH METHODS

Clinical trials were identified by searching CENTRAL, HTA, and DARE , (The Cochrane Library 2010 Issue 3), as well as MEDLINE (2002 to July 2010), and EMBASE (2002 to July 2010). Reference lists of retrieved articles and systematic reviews were checked for additional studies not identified by the electronic searches.

SELECTION CRITERIA

Double blind randomised controlled trials in men and women of all ages who have symptomatic (NYHA Class II to IV) HF and: 1) left ventricular systolic dysfunction, defined as left ventricular ejection fraction (LVEF) ≤40%; or 2) preserved ejection fraction, defined as LVEF >40%.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted data from included studies.

MAIN RESULTS

Twenty two studies evaluated the effects of ARBs in 17,900 patients with a LVEF ≤40% (mean 2.2 years). ARBs did not reduce total mortality (RR 0.87 [95% CI 0.76, 1.00]) or total morbidity as measured by total hospitalisations (RR 0.94 [95% CI 0.88, 1.01]) compared with placebo.Total mortality (RR 1.05 [95% CI 0.91, 1.22]), total hospitalisations (RR 1.00 [95% CI 0.92, 1.08]), MI (RR 1.00 [95% CI 0.62, 1.63]), and stroke (RR 1.63 [0.77, 3.44]) did not differ between ARBs and ACEIs but withdrawals due to adverse effects were lower with ARBs (RR 0.63 [95% CI 0.52, 0.76]). Combinations of ARBs plus ACEIs increased the risk of withdrawals due to adverse effects (RR 1.34 [95% CI 1.19, 1.51]) but did not reduce total mortality or total hospital admissions versus ACEI alone.Two placebo-controlled studies evaluated ARBs in 7151 patients with a LVEF >40% (mean 3.7 years). ARBs did not reduce total mortality (RR 1.02 [95% CI 0.93, 1.12]) or total morbidity as measured by total hospitalisations (RR 1.00 [95% CI 0.97, 1.05]) compared with placebo. Withdrawals due to adverse effects were higher with ARBs versus placebo when all patients were pooled irrespective of LVEF (RR 1.06 [95% CI 1.01, 1.12]).

AUTHORS' CONCLUSIONS

In patients with symptomatic HF and systolic dysfunction or with preserved ejection fraction, ARBs compared to placebo or ACEIs do not reduce total mortality or morbidity. ARBs are better tolerated than ACEIs but do not appear to be as safe and well tolerated as placebo in terms of withdrawals due to adverse effects. Adding an ARB in combination with an ACEI does not reduce total mortality or total hospital admission but increases withdrawals due to adverse effects compared with ACEI alone.

End-organ protection in patients with hypertension: focus on the role of angiotensin receptor blockers on renal function

The renin-angiotensin system (RAS) plays a key role in a number of pathophysiological mechanisms that are involved in the development and progression of cardiovascular and renal disease. For these reasons, pharmacological antagonism of this system, particularly the blockade of formation or the receptor antagonism of angiotensin II, has been demonstrated to be an effective and safe strategy to reduce the burden of cardiovascular disease. Among different drug classes, angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) have provided an excellent alternative to ACE inhibitors, representing a more selective and a better tolerated pharmacological approach to interfere with the RAS. Results derived from large, international, randomized clinical trials have consistently indicated that ARB-based therapeutic strategies may effectively provide cardiovascular and renal disease prevention and protection in different clinical conditions across the entire cardiovascular continuum. This article reviews the pathophysiological rationale of RAS involvement in the pathogenesis of renal diseases, focusing on the beneficial effects provided by ARBs in terms of renal protection.

Comparison of the efficacy and safety of azilsartan with that of candesartan cilexetil in Japanese patients with grade I-II essential hypertension: a randomized, double-blind clinical study

Azilsartan is a novel angiotensin receptor blocker being developed for hypertension treatment. This 16-week, multicenter, randomized, double-blind study compared the efficacy and safety of azilsartan (20–40 mg once daily by forced titration) and its ability to provide 24-h blood pressure (BP) control, with that of candesartan cilexetil (candesartan; 8–12 mg once daily by forced titration) in 622 Japanese patients with grade I–II essential hypertension. Efficacy was evaluated by clinic-measured sitting BP, and by ambulatory BP monitoring (ABPM) at week 14. Participants (mean age: 57 years, 61% males) had a mean baseline sitting BP of 159.8/100.4 mm Hg. The mean change from baseline in sitting diastolic BP at week 16 (primary endpoint) was −12.4 mm Hg in the azilsartan group and −9.8 mm Hg in the candesartan group, demonstrating a statistically significant greater reduction with azilsartan vs. candesartan (difference: −2.6 mm Hg, 95% confidence interval (CI): −4.08 to −1.22 mm Hg, P=0.0003). The week 16 (secondary endpoint) mean change from baseline in sitting systolic BP was −21.8 mm Hg and −17.5 mm Hg, respectively, a significant decrease with azilsartan vs. candesartan (difference: −4.4 mm Hg, 95% CI: −6.53 to −2.20 mm Hg, P<0.0001). On ABPM, the week 14 mean changes from baseline in diastolic and systolic BP were also significantly greater with azilsartan over a 24-h period, and during the daytime, night-time and early morning. Safety and tolerability were similar among the two groups. These data demonstrate that once-daily azilsartan provides a more potent 24-h sustained antihypertensive effect than that of candesartan but with equivalent safety.

Binding of losartan to angiotensin AT1 receptors increases dopamine D1 receptor activation

Signaling through both angiotensin AT1 receptors (AT1R) and dopamine D1 receptors (D1R) modulates renal sodium excretion and arterial BP. AT1R and D1R form heterodimers, but whether treatment with AT1R antagonists functionally modifies D1R via allosterism is unknown. In this study, the AT1R antagonist losartan strengthened the interaction between AT1R and D1R and increased expression of D1R on the plasma membrane in vitro. In rat proximal tubule cells that express endogenous AT1R and D1R, losartan increased cAMP generation. Losartan increased cAMP in HEK 293a cells transfected with both AT1R and D1R, but it did not increase cAMP in cells transfected with either receptor alone, suggesting that losartan induces D1R activation. Furthermore, losartan did not increase cAMP in HEK 293a cells expressing AT1R and mutant S397/S398A D1R, which disrupts the physical interaction between AT1R and D1R. In vivo, administration of a D1R antagonist significantly attenuated the antihypertensive effect of losartan in rats with renal hypertension. Taken together, these data imply that losartan might exert its antihypertensive effect both by inhibiting AT1R signaling and by enhancing D1R signaling.

Differential clinical profile of candesartan compared to other angiotensin receptor blockers

The advantages of blood pressure (BP) control on the risks of heart failure and stroke are well established. The renin-angiotensin system plays an important role in volume homeostasis and BP regulation and is a target for several groups of antihypertensive drugs. Angiotensin II receptor blockers represent a major class of antihypertensive compounds. Candesartan cilexetil is an angiotensin II type 1 (AT[1]) receptor antagonist (angiotensin receptor blocker [ARB]) that inhibits the actions of angiotensin II on the renin-angiotensin-aldosterone system. Oral candesartan 8–32 mg once daily is recommended for the treatment of adult patients with hypertension. Clinical trials have demonstrated that candesartan cilexetil is an effective agent in reducing the risk of cardiovascular mortality, stroke, heart failure, arterial stiffness, renal failure, retinopathy, and migraine in different populations of adult patients including patients with coexisting type 2 diabetes, metabolic syndrome, or kidney impairment. Clinical evidence confirmed that candesartan cilexetil provides better antihypertensive efficacy than losartan and is at least as effective as telmisartan and valsartan. Candesartan cilexetil, one of the current market leaders in BP treatment, is a highly selective compound with high potency, a long duration of action, and a tolerability profile similar to placebo. The most important and recent data from clinical trials regarding candesartan cilexetil will be reviewed in this article.

Comparison of the efficacy and tolerability of telmisartan and enalapril in patients of mild to moderate essential hypertension

Background:

Theoretically, angiotensin II receptor blockers (ARBs) have certain advantages over angiotensin-converting enzyme inhibitors, but the contribution of these advantages to the clinical effect of ARBs is not known.

Objective:

To compare the efficacy and tolerability of telmisartan with enalapril in patients of essential hypertension.

Materials and Methods:

Patients of mild to moderate hypertension were randomized to receive either 40 mg of telmisartan or enalapril 10 mg once a day orally for 12 weeks. At each visit, the systolic blood pressure (BP), diastolic BP and heart rate of each patient were recorded. Investigations such as hemogram hemoglobin, total leucocytes count (Hb, TLC), serum creatinine, serum glutamic oxaloacetic transaminase, serum glutamic pyruric transaminase (SGOT, SGPT) random blood sugar and urine examination were performed at baseline and after 12 weeks of the treatment period.

Results:

The mean reduction in systolic BP in the telmisartan/enalapril group was 26.38 ± 10.98/26.74 ± 8.24 mmHg while the mean reduction in diastolic BP in the telmisartan/enalapril group was 14 ± 2.98/9.71 ± 4.23 mmHg, respectively, at 12 weeks. When the reduction in systolic BP in the two groups was compared, there was no significant difference between the groups (P > 0.05). However, the mean reduction in diastolic BP achieved with telmisartan at 12 weeks was significantly higher (P < 0.001) than that achieved with enalapril after the corresponding period. The overall frequency of adverse-effects was similar. However, in the enalapril group, the incidence of dry cough was higher as compared to that in the telmisartan group (11.43% vs. 0%, respectively; P < 0.05).

Conclusion:

Telmisartan produces a greater reduction in diastolic BP than enalapril and is free from the adverse-effect of dry cough that is commonly encountered with enalapril.

Comparison of the novel angiotensin II receptor blocker azilsartan medoxomil vs valsartan by ambulatory blood pressure monitoring

Azilsartan medoxomil (AZL-M) is a unique angiotensin II receptor blocker (ARB) under development for the treatment of hypertension. To compare this ARB with another in the class, the authors studied the effects of AZL-M and valsartan (VAL) in 984 patients with primary hypertension in a randomized, double-blind, multicenter study using ambulatory and clinic blood pressure (BP) measurements. The primary end point was change from baseline in 24-hour mean ambulatory systolic BP following 24 weeks of treatment. Hierarchical analysis testing for noninferiority was followed by superiority testing of AZL-M (80 mg then 40 mg) vs VAL. The mean age of participants was 58 years, 52% were men, and 15% were black. Baseline 24-hour mean systolic BP was similar (approximately 145.6 mm Hg) in each group. AZL-M 40 mg and 80 mg lowered 24-hour mean systolic BP (-14.9 mm Hg and -15.3 mm Hg, respectively) more than VAL 320 mg (-11.3 mm Hg; P<.001 for 40-mg and 80-mg comparisons vs VAL). Clinic systolic BP reductions were consistent with the ambulatory results (-14.9 mm Hg for AZL-M 40 mg and -16.9 mm Hg for AZL-M 80 mg vs -11.6 mm Hg for VAL; P=.015 and P<.001, respectively). The reductions in 24-hour mean and clinic diastolic BPs were also greater with both doses of AZL-M than with VAL (P≤.001 for all comparisons). Small, reversible changes in serum creatinine occurred more often with AZL-M than with VAL; otherwise, safety and tolerability parameters were similar among the three groups. These data demonstrate that AZL-M across the effective dose range had superior efficacy to VAL at its maximal recommended dose without any meaningful increase in adverse events. These findings suggest that AZL-M could provide higher rates of hypertension control compared with other ARBs in the class.

Olmesartan/amlodipine: a review of its use in the management of hypertension

Combination therapy is an effective strategy to increase antihypertensive efficacy in those patients with poor blood pressure (BP) control. In order to achieve BP targets, at least 75% of patients may require combination therapy, and European guidelines advocate this approach, particularly in those patients with a high cardiovascular risk. Evidence from large, randomized controlled trials, and the European hypertension treatment guidelines is supportive of the use of an angiotensin receptor blocker (ARB) with a calcium channel blocker (CCB). Fixed-dose combination formulations of olmesartan medoxomil, an ARB, and the CCB amlodipine are approved in several European countries for patients with essential hypertension. The olmesartan/amlodipine combination has demonstrated greater efficacy than its component monotherapies in reducing BP in patients with mild-to-severe hypertension. Significantly greater reductions in seated diastolic BP were observed between baseline and after eight weeks of treatment with olmesartan/amlodipine, compared with equivalent doses of olmesartan or amolodipine monotherapy (P < 0.001), in the factorial Combination of Olmesartan Medoxomil and Amlodipine Besylate in Controlling High Blood Pressure (COACH) trial. About 85% of the maximal BP reductions after the 8-week treatment period were already observed after two weeks. Uptitration as necessary, with or without hydrochlorothiazide, allowed the majority of patients to achieve BP control in a 44-week open-label extension treatment period to the COACH trial. The use of olmesartan/amlodipine allowed up to 54% of patients, with previously inadequate responses to amlodipine or olmesartan monotherapy, to achieve their BP goals. Data from post-registration studies using tight BP control and forced titration regimens have further demonstrated the high efficacy of olmesartan/amlodipine in achieving BP goal rates. Moreover, consistent reductions in BP were observed over the 24-hour dosing interval using ambulatory measurements. Olmesartan/amlodipine was generally well tolerated over the short- and long-term, with a lower frequency of peripheral edema with olmesartan/amlodipine 40/10 mg than with amlodipine 10 mg monotherapy.

Pharmacokinetic evaluation of losartan

INTRODUCTION

Blockade of the renin-angiotensin system is one of the major therapeutic strategies in the management of patients with essential hypertension, congestive heart failure and diabetic as well as non-diabetic renal diseases. As the first angiotensin II receptor blocker (ARB) on the market, losartan belongs to the most frequently prescribed ARB.

AREA COVERED

The present review examines the pharmacokinetics of losartan with a special discussion on the dose of losartan that should be used in clinical practice to obtain the maximal benefits of the drug. Readers are provided with arguments suggesting that the dose of 50 mg losartan is probably too low and that losartan should preferably be prescribed at the dose of 100 mg/day or higher.

EXPERT OPINION

Losartan is an effective antagonist of angiotensin II AT(1) receptors which has been shown to provide important clinical benefits in patients with hypertension, congestive heart failure and renal diseases. Losartan should be prescribed at the dose of 100 mg/day and the use of higher doses should be reconsidered in future studies to improve its clinical efficacy.

In vitro antagonistic properties of a new angiotensin type 1 receptor blocker, azilsartan, in receptor binding and function studies

The angiotensin II (AII) antagonistic action of azilsartan (AZL) [2-ethoxy-1-{[2'-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl)biphenyl-4-yl]methyl}-1H-benzimidazole-7-carboxylic acid] was investigated in radioligand binding and function studies. AZL inhibited the specific binding of ¹²⁵I-Sar¹-Ile⁸-AII to human angiotensin type 1 receptors with an IC₅₀ of 2.6 nM. The inhibitory effect of AZL persisted after washout of the free compound (IC(50) value of 7.4 nM). Olmesartan, telmisartan, valsartan, and irbesartan also inhibited the specific binding with IC₅₀ values of 6.7, 5.1, 44.9, and 15.8 nM, respectively. However, their inhibitory effects were markedly attenuated with washout (IC₅₀ values of 242.5, 191.6, >10,000, and >10,000 nM). AZL also inhibited the accumulation of AII-induced inositol 1-phosphate (IP1) in the cell-based assay with an IC₅₀ value of 9.2 nmol; this effect was resistant to washout (IC₅₀ value of 81.3 nM). Olmesartan and valsartan inhibited IP1 accumulation with IC₅₀ values of 12.2 and 59.8 nM, respectively. The activities of these compounds were markedly reduced after washout (IC₅₀ value of 908.5 and 22,664.4 nM). AZL was defined as an inverse agonist in an experiment by using a constitutively active mutant of human angiotensin type 1 receptors. In isolated rabbit aortic strips, AZL reduced the maximal contractile response to AII with a pD'₂ value of 9.9. The inhibitory effects of AZL on contractile responses induced by AII persisted after the strips were washed; these inhibitory effects were more potent than those of olmesartan. These results suggest that AZL is a highly potent and slowly dissociating AII receptor blocker. Its tight receptor binding might be expected to produce potent and long-lasting antihypertensive effects in preclinical and clinical settings.

Telmisartan: a review of its pharmacodynamic and pharmacokinetic properties

IMPORTANCE OF THE FIELD

Telmisartan belongs to the angiotensin II type 1 (AT1) receptor antagonizing class of antihypertensives, which are widely recognized and increasingly prescribed because of their good tolerability. Moreover, due to the results of the ONTARGET trial program, telmisartan was the first AT1 receptor antagonist to receive approval for the prevention of cardiovascular events in cardiovascular high risk patients, thereby, indicating that its clinical importance will further increase.

AREAS COVERED IN THIS REVIEW

This article reviews the pharmacokinetic and pharmacodynamic properties of telmisartan with a special focus on novel pharmacokinetic characteristics of the drug.

WHAT THE READER WILL GAIN

An overview of the published data regarding the pharmacokinetic properties of telmisartan as well as a summary of the results from selected small exploratory and large clinical outcome trials involving telmisartan.

TAKE HOME MESSAGE

Telmisartan is a safe and effective alternative for the treatment of hypertension. Moreover, due to its good tolerability, an increasing use of telmisartan in cardiovascular high risk patients can be anticipated. This will grant further experimental and clinical research on AT1 receptor-independent pharmacodynamics of telmisartan as well as on telmisartan-related drug safety issues.

Chronopharmacology of angiotensin II-receptor blockers in stroke-prone spontaneously hypertensive rats

Protective effect of valsartan (Val), an angiotensin II (AII)-receptor blocker (ARB), against organ damage is reported to depend on the dosing time in hypertensive patients. Dosing-time-dependent effect of Val on survival of stroke-prone spontaneously hypertensive rats (SHRSP) under a 12-h lighting cycle was examined. Val (4 mg/kg per day) and olmesartan medoxomil (OM) (1 mg/kg per day), another ARB with a slower dissociation from the AII receptor, were given once daily at 2, 8, 14, or 20 HALO (hours after lights on). Dosing-time-dependent differences in plasma drug concentrations and effect on blood pressure (BP) were also evaluated. Survival of SHRSP showed a dosing-time-dependent change during Val therapy, with a peak at 2 HALO and a trough at 14 HALO. OM equally prolonged survival in all groups. The BP-lowering effect persisted for more than 24 h after dosing of Val at 2 HALO and of OM at 2 and 14 HALO, but disappeared at 5.5-h after Val dosing at 14 HALO. Plasma concentrations of Val and OM were higher after dosing at 2 HALO than at 14 HALO. These results suggest that the chronopharmacological phenomenon of Val was partly due to the dosing-time-dependent difference in plasma concentration and subsequent duration of the antihypertensive effect. Slower dissociation of OM from AII receptors might have blunted a potential dosing-time-dependent event.

Eprosartan: a review of its use in hypertension

Eprosartan is an angiotensin II receptor antagonist (angiotensin II receptor blocker [ARB]) used in the treatment of hypertension. In large, randomized trials, eprosartan (with or without hydrochlorothiazide [HCTZ]) demonstrated superior antihypertensive efficacy to that of placebo and, when administered at comparable dosage regimens, had similar blood pressure-lowering effects to enalapril. Eprosartan was generally well tolerated in clinical trials and had a lower incidence of persistent dry cough than enalapril. Eprosartan has a neutral effect on metabolic parameters, such as serum lipid levels and glucose homeostasis, and a low propensity for pharmacokinetic drug interactions. The use of eprosartan or other ARBs in combination with HCTZ tends to reverse the potassium loss associated with thiazide diuretics. Independent of its antihypertensive effects, eprosartan was associated with improved clinical outcomes (primary composite endpoint of all causes of mortality and all cardiovascular and cerebrovascular events, including all recurrent events) compared with nitrendipine in a randomized, secondary prevention trial in hypertensive patients with previous cerebrovascular events (MOSES trial). Eprosartan also reduced blood pressure and was associated with a modest improvement in cognitive function in a large observational study in patients > or =50 years of age with newly diagnosed hypertension (OSCAR study). In both of these trials, additional antihypertensive therapy, such as HCTZ, was permitted. Therefore, eprosartan is a useful treatment option in the management of a broad range of patients with hypertension, and its use with HCTZ provides a rational combination regimen.

Diabetes and obesity: therapeutic targeting and risk reduction - a complex interplay

Obesity is a major risk factor for the development of diabetes and predisposes individuals to hypertension and dyslipidaemia. Together these pathologies increase the risk for cardiovascular disease (CVD), the major cause of morbidity and mortality in type 2 diabetes mellitus (T2DM). Worsening trends in obesity and T2DM raise a serious conundrum, namely, how to control blood glucose, blood pressure, and lipids when many antidiabetic agents cause weight gain and thereby exacerbate other cardiovascular risk factors associated with T2DM. Further, evidence suggests that some established antihypertensive agents may worsen glucose intolerance. Many patients who are obese, hypertensive, and/or hyperlipidaemic fail to achieve blood pressure, lipid and glycaemic goals, and this failure may in part be explained by physician reluctance to utilize complex combination regimens for fear of off-target effects. Thus, a clear need exists for clinicians to understand the risks and benefits of different pharmacologic, and indeed non-pharmacologic, options in order to maximize treatment outcomes. While intensive lifestyle modification remains an elusive gold standard, newer diabetes targets, including the incretin axis, may offer greater cardiovascular risk reduction than other antidiabetes therapies, although definitive clinical trial data are needed. The glucagon-like peptide-1 (GLP-1) receptor agonists exenatide and liraglutide and the dipeptidyl peptidase-4 (DPP-4) inhibitors sitagliptin and vildagliptin effectively lower HbA1c; exenatide and liraglutide reduce weight and blood pressure and improve lipid profiles. Sitagliptin and vildagliptin are weight neutral but also appear to improve lipid profiles. Integration of incretin therapies into the therapeutic armamentarium is a promising approach to improving outcomes in T2DM, and perhaps even in reducing complications of T2DM, such as co-morbid hypertension and dyslipidaemia. Additional long-term studies, including CVD end-point studies, will be necessary to determine the appropriate places for incretin-based therapies in treatment algorithms.

The treatment of hypertension with telmisartan in the sphere of circadian rhythm in metabolic syndrome in the elderly

This study compares the efficacy of telmisartan with that of valsartan and ramipril in reducing blood pressure (BP) over 24 hrs in the elderly patients with metabolic syndrome (MS). This prospective and open label study analyzed a sample of 60 patients over 65 years of age with hypertension and with MS. At the beginning the BP was monitored by a 24-hr ambulatory blood pressure monitoring (AMBP). Following this, the 60 patients were divided into 3 groups of 20, to each of which was prescribed, respectively, telmisartan, valsartan and ramipril to take for 12 weeks. The drugs were to be taken at 9.00 a.m. Later on the doses were increased. After 12 weeks of therapy, BP was monitored by a 24-hr AMBP. The use of telmisartan caused a greater reduction of the BP in the final 4-6 hours of the period between the 1st administration of the drug and the next one, these last 4-6 hours being those when cardiovascular and cerebrovascular accidents are more frequent (between 6.00 and 10.00 a.m.). Comparing to valsartan and ramipril, telmisartan results in excellent pressure control during the last 4-6 hours between the 1st administration of the drug and the next one.

Choosing among renin-angiotensin system blockers for the management of hypertension: from pharmacology to clinical efficacy

BACKGROUND

Hypertension is an important healthcare challenge, yet despite initiatives to improve detection and advances in therapy, the majority of patients do not achieve recommended blood pressure targets and remain at high cardiovascular risk. Physicians are confronted with an array of antihypertensive agents, accompanied by increasingly complex and often conflicting evidence regarding their efficacy and tolerability.

SCOPE

An extensive PubMed and Cochrane database search was conducted to identify clinical literature (published 1990-2009) on the blood pressure lowering efficacy, tolerability and target organ protection of angiotensin converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs). While not a systematic review, this article reviews the best available evidence in an attempt to clarify current uncertainty within medical practice regarding treatment options in patients with hypertension.

FINDINGS

ACEIs have been at the forefront of hypertension therapy for several years, especially in hypertensive at-risk patients. However, their use is restricted by burdensome side-effects and their limited ability to reach target blood pressure. Newer ARBs, such as telmisartan, have more sustained blood pressure control throughout the 24-h dosing period compared with ACEIs and other ARBs. For uncomplicated hypertension, ARBs are preferred to ACEIs because of their superior tolerability and adherence. In specific patient populations, namely heart failure patients, ARBs have previously shown equal cardiovascular protection to ACEIs. ONTARGET showed that an ARB, in this case telmisartan, was as effective as ramipril in reducing cardiovascular events in a wide cross-section of at-risk cardiovascular patients, but was better tolerated even though patients were screened for ACEI tolerance.

CONCLUSION

Telmisartan is currently the only ARB to have demonstrated equivalence to ramipril in reducing cardiovascular events in a broad patient population. In practical terms, telmisartan is superior to the reference standard ramipril because of more powerful blood pressure lowering and superior tolerability. However, in many countries, guidance to physicians prioritizes ACEIs. In these countries, telmisartan should be the first choice ARB for hypertensive at-risk patients who do not achieve adequate blood pressure control with an ACEI, or for whom tolerability is a concern.

Angiotensin receptor blocker and dihydropyridine calcium channel blocker combinations: an emerging strategy in hypertension therapy

Hypertension is a leading contributor to the burden of cardiovascular disease. The importance of lowering blood pressure (BP) to reduce the risk of cardiovascular events has been demonstrated in numerous clinical trials. Most patients require combination antihypertensive therapy utilizing agents from complementary drug classes to achieve BP goals. A calcium channel blocker (CCB)/angiotensin receptor blocker (ARB) combination is a rational approach for such an antihypertensive strategy. Benefits of CCB/ARB combination therapy include additive BP-lowering effects and lower incidences of adverse events (AEs). These agents demonstrate benefits associated with their respective drug classes. The ARBs confer stroke protection, renal protection, and tolerability similar to placebo, without dose-related symptomatic and metabolic AEs, while CCBs are beneficial in reducing stroke and treating angina and cardiac ischemia. The efficacy of this combination has been recently investigated in clinical trials wherein amlodipine was combined with olmesartan medoxomil or valsartan. This article discusses the rationale for using CCB/ARB combinations in patients with hypertension.

Complementary mechanisms of angiotensin receptor blockers and calcium channel blockers in managing hypertension

Hypertension affects approximately 73 million individuals in the United States. Clinical studies have shown that antihypertensive therapy can reduce blood pressure (BP) and the risk of cardiovascular events. However, the majority of patients with hypertension do not achieve the recommended BP goal of < 140/90 mm Hg (or < 130/80 mm Hg for patients with diabetes) with antihypertensive monotherapy, and require therapy with 2 or more antihypertensive agents. Combination therapy utilizes antihypertensive agents from different drug classes, which act via distinct pharmacologic mechanisms to improve overall efficacy and tolerability. Although combination therapy is superior to monotherapy in achieving BP goals across the entire spectrum of hypertension, the proportion of patients achieving the recommended BP goal can be further improved by the use of new antihypertensive drug combinations. The beneficial antihypertensive characteristics of both angiotensin receptor blockers and calcium channel blockers suggest that combining these classes may result in a highly efficacious antihypertensive therapy with regard to both activity and safety when used as a fixed-dose combination. In particular, a fixed-dose combination of olmesartan medoxomil plus amlodipine besylate has been demonstrated to be an efficacious antihypertensive combination due in part to the benefits associated with each of these agents within their respective drug classes.