Pharmacological differences among angiotensin II receptor antagonists

The role of eprosartan in the management of essential hypertension: literature review and expert opinion

INTRODUCTION

Eprosartan is an angiotensin receptor blocker (ARB) used for management of essential hypertension. With unique pharmacological characteristics, dual action mechanism, and clinical effectiveness, eprosartan offers additional advantages over other ARBs in specific patient populations.

AREAS COVERED

A comprehensive review of the literature was performed across publicly available databases, with no time limitations, to ensure the inclusion of all relevant studies. The review focuses on presenting the efficacy and safety profile of eprosartan, alone or in combination with other agents. Additionally, it explores the etiology of hypertension concerning the structure and function of angiotensin II type 1 receptors. Further, the efficacy of eprosartan in special populations and its additional benefits are also discussed.

EXPERT OPINION

Eprosartan effectively reduces blood pressure (BP), with a 24-hour BP-lowering effect at 600 mg/day. Eprosartan demonstrates similar or better efficacy than other ARBs, such as telmisartan and losartan, particularly in managing coagulation-related abnormalities and peripheral resistance. In combination therapy, eprosartan with hydrochlorothiazide significantly enhances BP reduction. Eprosartan is well-tolerated, with a low incidence of adverse events, making it a reliable choice for long-term hypertension management across various patient populations, such as those with comorbid diabetes and renal disease and older adults.

Efficacy and tolerability of candesartan cilexetil/hydrochlorothiazide and amlodipine in patients with poorly controlled mild-to-moderate essential hypertension

The antihypertensive efficacy and tolerability of combination therapy with candesartan cilexetil, 16 mg plus hydrochlorothiazide (CC/HCTZ), 12.5 mg was compared with that of amlodipine, in a multicentre, double-blind, randomised, parallel-group study in patients with mild-to-moderate essential hypertension inadequately controlled by monotherapy.After a two week run-in period on existing therapy, patients with a sitting diastolic blood pressure (DBP) of 90—110 mmHg and a sitting systolic blood pressure (SBP) < 180 mmHg were switched to either CC/HCTZ (n=101) or amlodipine (n=102), once-daily by mouth. After eight weeks of AA treatment, both regimens reduced mean trough blood pressure (BP) by a similar amount: mean sitting SBP/DBP reductions were -15.4/-11.9 mmHg for CC/HCTZ, and -15.7/-12.0 mmHg for amlodipine (group differences, p=0.835/0.963). The BP of 84.2% of patients on CC/HCTZ and 84.5% on amlodipine was controlled (sitting DBP < 90 mmHg and sitting SBP < 140 mmHg) (p=1.00). Six (5.9%) patients on CC/HCTZ and 18 (17.6%) on amlodipine discontinued treatment, including one (1% O ) and 12 (11.8%) owing to ad C verse events R (p<0.001).The most common adverse event was peripheral oedema, which occurred in two patients on CC/HCTZ and 19 on amlodipine. In conclusion, CC/HCTZ and amlodipine were equally effective in reducing BP in hypertensive patients not controlled by monotherapy, but CC/HCTZ was much better tolerated.Tolerance is an important clinical consideration in the chronic treatment of an asymptomatic disease.

Economic impact of switching from metoprolol to nebivolol for hypertension treatment: a retrospective database analysis

OBJECTIVE

To estimate the real-world economic impact of switching hypertensive patients from metoprolol, a commonly prescribed, generic, non-vasodilatory β1-blocker, to nebivolol, a branded-protected vasodilatory β1-blocker.

METHODS

Retrospective analysis with a pre-post study design was conducted using the MarketScan database (2007-2011). Hypertensive patients continuously treated with metoprolol for ≥6 months (pre-period) and then switched to nebivolol for ≥6 months (post-period) were identified. The index date for switching was defined as the first nebivolol dispensing date. Data were collected for the two 6-month periods pre- and post-switching. Monthly healthcare resource utilization and healthcare costs pre- and post-switching were calculated and compared using Wilcoxon test and paired t-test. Medical costs at different years were inflated to the 2011 dollar.

RESULTS

In total, 2259 patients (mean age: 60 years; male: 52%; cardiovascular [CV] disease: 37%) met the selection criteria. Switching to nebivolol was associated with statistically significant reductions in the number of all-cause hospitalization (-33%; p < 0.01), CV-related hospitalizations (-60%; p < 0.01), and outpatient visits (-7%; p < 0.01). Monthly inpatient costs were reduced by $111 (p < 0.01), while monthly drug costs increased by $52 (p < 0.01). No statistically significant differences were found in overall costs and costs of outpatient or ER visits. Sensitivity analyses, conducted using various lengths of medication exposure, controlling for spill-over effect or excluding patients with compelling indications for metoprolol, all found some level of reduction in resource utilization and no significant difference in overall healthcare costs.

CONCLUSIONS

This real-world study suggests that switching from metoprolol to nebivolol is associated with an increase in medication costs and significant reductions in hospitalizations and outpatient visits upon switching, resulting in an overall neutral effect on healthcare costs. These results may be interpreted with caution due to lack of a comparator group and confounding control caused by design and limitations inherent in insurance claims data.

Candesartan

Candesartan cilexetil is the prodrug of candesartan, an angiotensin II receptor antagonist. Candesartan binds selectively and non-competitively to the angiotensin II receptor type 1, thus preventing the actions of angiotensin II. Clinical trials have demonstrated its efficacy at a dose range of 2 to 32 mg once daily in hypertension of all grades, heart failure, in reducing urinary albumin excretion in diabetes mellitus and in coexisting hypertension and renal failure. Pharmacokinetic properties of candesartan cilexetil in elderly patients are not significantly different from those in younger individuals. Hepatic impairment does not change pharmacokinetics of candesartan cilexetil at doses up to 12 mg/day. No dose adjustment is necessary in patients with mild or moderate renal impairment. Tolerability of candesartan cilexetil is not much different from that of placebo. All adverse events are usually of mild to moderate severity and not dose-related. The most common adverse events were headache, upper respiratory tract infection, back pain, and dizziness. The incidence of these adverse effects, as well as of cough, was similar in patients treated with candesartan cilexetil or placebo. The incidence of adverse events in long-term trials was not different from that in short-term trials. Tolerability of candesartan cilexetil does not differ with either age or gender.

Targeting effective blood pressure control with angiotensin receptor blockers

Angiotensin receptor blockers (ARBs) have become established as a major class of antihypertensive on the basis of their powerful effects on blood pressure (BP), excellent tolerability and pleiotropic end-organ-protective effects. However, individual ARBs vary in antihypertensive efficacy, which may be important to clinical outcome. Several strategies are available to ensure that BP reductions with ARBs are at least as great as that which can be achieved with other antihypertensive classes. Firstly, several newer ARBs, including irbesartan, candesartan, telmisartan and olmesartan, have been reported to provide equivalent antihypertensive efficacy to amlodipine and greater efficacy than either losartan, valsartan or both. Secondly, increases in dose may improve the antihypertensive efficacy of agents such as valsartan, although clinical studies are necessary to provide characterisation of new, higher-dose monotherapies. Thirdly, fixed dose combinations with hydrochlorothiazide (HCTZ) increase the antihypertensive effect of all ARBs. It is likely that differences in efficacy between newer and older ARBs will in some cases be sustained in combination therapy, such that the most potent ARBs and HCTZ will provide another tier of control. The future use of ARBs is likely to involve a growing emphasis on compound-specific data, with regard to the antihypertensive efficacy and pleiotropic protective actions of agents.

Automated office and home phone-transmitted blood pressure recordings in uncontrolled hypertension treated with valsartan and hydrochlorothiazide

The study objective was to evaluate, by means of automated office and phone-transmitted home blood pressure (OBP and HBP) recordings, the effects of a fixed combination of valsartan 160 mg and hydrochlorothiazide (HCTZ) 25 mg in hypertensive patients previously uncontrolled with the combination of an angiotensin receptor antagonist and HCTZ. From 241 selected patients, 171 (71%) had uncontrolled hypertension OBP and HBP [mean baseline OBP and HBP systolic and diastolic (SBP/DBP): 157/91 and 152/87 mmHg]. In this open-design study, patients were directly switched from other angiotensin receptor blocker combination products to valsartan/HCTZ for 6 weeks. The same validated automated device was used for OBP and HBP recordings. At baseline, mean HBP was 152 +/- 15/87 +/- 10 mmHg and mean OBP was 157 +/- 12/91 +/- 9 mmHg. After 6 weeks of treatment with valsartan 160 mg and HCTZ 25 mg, a significant decrease in BP was observed both at home (146 +/- 17/83 +/- 12 mmHg) and at the office (151 +/- 18/87 +/- 11 mmHg), with a difference from baseline of -4 mmHg, p < 0.001 for DBP and of -6 mmHg for SBP, p < 0.001. The percentage of patients with office and home control was 24% and 23% respectively, with a kappa index at 0.459. Elevated OBP only (office hypertension) was observed in 3.6% and elevated HBP only (masked hypertension) in 10% of patients. In conclusion, treatment with valsartan and HCTZ 25 mg in patients with confirmed uncontrolled hypertension induced a clinically relevant decrease in BP with approximately 23% of additional patients strictly controlled with a single tablet. The use of an automated oscillometric device at the office and at home allowed the detection of controlled subjects with good agreement.

Normalización del intercambio terapéutico de antagonistas del receptor de la angiotensina-II para el tratamiento de la hipertensión en el medio hospitalario

INTRODUCTION

Standardization of the therapeutic inter change process in the hospital setting by the establishment and spreading of standard criteria has been defined as an activity conducent to increased health care quality, and hence improved patient care.

OBJECTIVE

To establish standardized therapeutic swapping for angiotensin II receptor antagonists (ARA-II) in the treatment of blood hypertension, and to evaluate the suitability of therapeutic interchange in an integrated individualized drug dispensation system.

MATERIAL AND METHODS

Standardized therapeutic inter-change was performed based on therapeutic equivalence criteriafor ARA-Ils such as candesartan, eprosartan, irbesartan, losartan,olmesartan, telmisartan, and valsartan, according to the pharmacodynamic characteristics, dosage recommendations, pharmacokinetic characteristics and interactions of each one of them. The suitability of therapeutic interchange was assessed in terms of standardization or adaptation to this practice developed by using percentage adherence in the previous 12 months (period A) and during the 12 months following its implementation and spread(period B).

RESULTS

The only ARA-II included in the hospital's pharmacotherapeutic guide is losartan, on which standardized therapeutic interchange for initial and maintenance doses of any drug within this class was based. The overall number of interchanges per-formed was 417-216 during period A and 201 during period B. Implementing therapeutic swapping has significantly increased adherence to explicitly established criteria by 35.2% (95% CI:25.9 to 44.5%). Similarly, during period B a reduction in the variability of therapeutic interchanges among various pharmacists was observed regarding losartan dosage.

DISCUSSION

The standardization of therapeutic interchange procedures for ARA-lls allowed a reduction of the variability seen in this process, and hence the potential for medication-related problems. Another benefit of the spread of therapeutic swapping has been an increased adjustment of medical prescriptions to the hospital's pharmacotherapeutic guide.

Effects of candesartan and probucol on restenosis after coronary stenting: results of insight of stent intimal hyperplasia inhibition by new angiotensin II receptor antagonist (ISHIN) trial

The purpose of this study was to determine whether candesartan and its combination with probucol reduce restenosis after coronary stenting. A total of 132 patients who successfully underwent stenting were randomly assigned to a control group (n=45), a candesartan group (8 mg daily, n=43), or a candesartan plus probucol group (+ probucol 500 mg daily, n=44). No differences in late loss were observed between the control and candesartan groups. In the candesartan plus probucol group, late loss was significantly smaller than in the control and candesartan groups (p=0.003, 0.015). The restenosis rate was 27% in the control group, 26% in the candesartan group (p>0.99), and 11% in the candesartan plus probucol group (p=0.104 vs the control group and p=0.103 vs the candesartan group). Intravascular ultrasound revealed no differences in stent area among the 3 groups, and no differences in lumen area or in intimal hyperplasia area between the control and candesartan groups. However, the intimal hyperplasia area in the candesartan plus probucol group was significantly less than that in the control and candesartan groups (p<0.001, p<0.001). This study demonstrated that candesartan failed to inhibit the neointimal hyperplasia and although the combination treatment did reduce neointimal hyperplasia, it did not statistically reduce the restenosis rate.

The effects of valsartan on insulin sensitivity in patients with primary hypertension

Insulin resistance is an important risk factor of cardiovascular disease. This study was performed to determine the effects of valsartan on insulin sensitivity in patients with primary hypertension. In this study, non-obese subjects with primary hypertension and a reference group of healthy subjects matched by age, sex and body mass index were evaluated; patients with any other causes of peripheral insulin resistance and hyperlipidaemia were excluded. The effect of valsartan on insulin resistance, assessed by homeostasis model assessment (HOMA-IR), fasting serum insulin levels, determined by radioimmunoassay, and fasting blood glucose concentrations, measured by the glucose oxidase method, were evaluated. All obtained data were evaluated by Pearson correlation analysis. Before valsartan treatment, the fasting serum insulin levels were significantly elevated in the 20 hypertensive patients with primary hypertension compared with the 20 subjects in the reference group (19.6 +/- 7.1 versus 8.7 +/- 1.9 microIU/ml). The fasting serum insulin levels correlated with HOMA-IR. Correlation analysis also showed a significant relationship between HOMA-IR and both systolic and diastolic blood pressures (r = 0.71 and r = 0.77, respectively). In our study, we showed that patients with primary hypertension have a decreased insulin sensitivity that was reflected in high serum fasting insulin levels. Anti-hypertensive treatment with valsartan increases insulin sensitivity.