The antihypertensive effect and tolerability of candesartan cilexetil, a new generation angiotensin II antagonist, in comparison with losartan

The Impact of an 8-Week Supplementation with Fermented and Non-Fermented Aronia Berry Pulp on Cardiovascular Risk Factors in Individuals with Type 2 Diabetes

Aronia berries contain antioxidants that may be health-promoting, e.g., demonstrated positive effects on hypertension and dyslipidaemia. There is a close link between cardiovascular diseases and hypertension and dyslipidaemia, and cardiovascular events are the leading cause of death among subjects with type 2 diabetes (T2D). Thus, we investigated the effect of an 8-week supplementation with fermented aronia extract (FAE), non-fermented aronia extract (AE), and placebo on cardiovascular risk factors. Snack bars were produced containing 34 g (37%) aronia extract, or 17 g (21%) wheat bran for placebo, as well as raisins and coconut oil. The study was randomized and blinded with a triple-crossover design. We examined the effects of aronia extracts on blood pressure, adiponectin, and high-sensitive C-reactive protein, and found no effects. After supplementation with placebo, there were significantly higher blood concentrations of total cholesterol, LDL-cholesterol, and HDL-cholesterol, with the placebo group showing significantly higher increases in total cholesterol and LDL-cholesterol than the AE group. Furthermore, we observed an increase in HDL-cholesterol in the FAE group and an increase in triglyceride in the AE group. Thus, we assume that the raisins may have increased the participants' cholesterol levels, with both AE and FAE having the potential to prevent this increase.

Is the newest angiotensin-receptor blocker azilsartan medoxomil more efficacious in lowering blood pressure than the older ones? A systematic review and network meta-analysis

Angiotensin‐receptor blockers are often considered insufficiently efficacious in reducing blood pressure. However, newer angiotensin‐receptor blockers may be more effective than the older ones. A network meta‐analysis was performed to compare the efficacy of various angiotensin‐receptor blockers in reducing office and ambulatory blood pressure in hypertensive patients. Relevant literature was searched from English and Chinese databases for randomized controlled trials involving angiotensin‐receptor blockers in hypertension. Efficacy variables included systolic and diastolic blood pressure either in the office or on ambulatory blood pressure monitoring. Absolute blood pressure reductions at 6‐12 weeks of treatment and their credible intervals were reported. A total of 34 publications provided adequate data for analysis (n = 14 859). In 28 studies on office systolic blood pressure (n = 12 731), against the common comparator valsartan 80 mg, the differences in systolic blood pressure were in favor of azilsartan medoxomil (20‐80 mg), irbesartan (300 mg), olmesartan (20‐40 mg), telmisartan (80 mg), and valsartan (160‐320 mg), but not candesartan (8‐16 mg), losartan (50‐100 mg), irbesartan (150 mg), olmesartan (10 mg), and telmisartan (40 mg). The ranking plot shows that azilsartan medoxomil 80 mg had a possibility of 99% being the best in the class. Similar results were observed for office diastolic blood pressure and from 13 studies for 24‐hour ambulatory systolic and diastolic blood pressure. In conclusion, angiotensin‐receptor blockers had different blood pressure lowering efficacy. The newest angiotensin‐receptor blocker azilsartan medoxomil at the dose of 80 mg seemed to be most efficacious in reducing both systolic and diastolic blood pressure in the office and on ambulatory measurement.

Twice-daily versus once-daily lisinopril and losartan for hypertension: Real-world effectiveness and safety

BACKGROUND

Lisinopril and losartan manufacturer labels recommend twice-daily dosing (BID) if once-daily (QDay) is insufficient to lower blood pressure (BP).

METHODS AND RESULTS

Retrospective cohort study of patients taking QDay lisinopril and losartan who experienced a dose-doubling (index date). A text-processing tool categorized BID and QDay groups at the index date based on administration instructions. We excluded: pregnant/hospice, regimens other than BID/QDay, and without BP measurements -6 months/+12 months of the index date. The most proximal BP measurements -6 months and +2 weeks to 12 months of the index date were used to evaluate BP differences. Propensity scores were generated, and differences in BP and adverse events (angioedema, acute kidney injury, hyperkalemia) between BID/QDay groups were analyzed within dosing cohorts using inverse propensity of treatment-weighted regression models. Of 11,210 and 6,051 patients who met all criteria for lisinopril and losartan, 784 (7.0%) and 453 (7.5%) were taking BID, respectively. BID patients were older and had higher comorbidity and medication burdens. There were no differences in systolic/diastolic BP between BID and QDay, with absolute differences in mean systolic BP ranging from -1.8 to 0.7 mmHg and diastolic BP ranging from -1.1 to 0.1 mmHg (all 95% confidence intervals [CI] cross 0). Lisinopril 10mg BID was associated with an increased odds of angioedema compared to lisinopril 20mg QDay (odds ratio 2.27, 95%CI 1.13-4.58).

CONCLUSIONS

Adjusted models do not support improved effectiveness or safety of BID lisinopril and losartan.

[Gerontology Issues in Cardiology Practice]

Increase in life expectancy during the second part of the 20th century is accompanied by increase in proportion of elderly and senile age population. However, despite the increase in life expectancy, the prevalence of most chronic diseases and functional impairments rises with age. Elderly and senile age is associated with the risk of cardiovascular diseases (CVD), therefore the problem of managing elderly patients with CVD becomes especially urgent.

A Randomized, Double-blind, Candesartan-controlled, Parallel Group Comparison Clinical Trial to Evaluate the Antihypertensive Efficacy and Safety of Fimasartan in Patients with Mild to Moderate Essential Hypertension

PURPOSE

A new antihypertensive drug that selectively blocks angiotensin II receptor type 1, fimasartan, has a potent and rapidly acting antihypertensive effect. We investigated the antihypertensive effects of fimasartan 60 and 120 mg and its safety in comparison to 8 mg of candesartan.

METHODS

This clinical trial is a multicenter, randomized, double-blind, active comparator, and parallel group study. Three hundred sixty-two individuals were screened, and 290 patients aged 19 to 75 years with mild to moderate hypertension (diastolic blood pressure [DBP], 90-110 mm Hg) were randomly assigned to 60 to 120 mg/d of fimasartan or 8 mg/d of candesartan after a 2-week placebo run-in period. Treatments were administered for 12 weeks without dosage adjustment. The primary end point was the differences in DBP changes at week 12.

FINDINGS

After 12 weeks of treatment, DBP and systolic blood pressure (SBP) decreased significantly in all 3 groups. The decrease in DBP at week 12 was larger but not statistically significant in the fimasartan 60 mg compared with the candesartan 8 mg group with a mean (SD) difference of 1.72 (8.32) mm Hg (95% CI, -0.71 to 4.15 mm Hg; P = 0.17). The lower margin of the CI (-0.71 mm Hg) exceeded the noninferiority margin (-3.5 mm Hg). The DBP-lowering effect of fimasartan 120 mg was also nonsignificantly larger than candesartan 8 mg (difference, 1.58 [8.27] mm Hg; P = 0.20). The decrease in SBP was also nonsignificantly larger in the fimasartan 60 mg group compared with the candesartan 8 mg group (difference, 3.50 [12.63] mm Hg; P = .06). The SBP-lowering effect of fimasartan 120 mg was statistically larger than candesartan 8 mg (difference, 4.98 [13.99] mm Hg; P = .02). Response rate (DBP <90 mm Hg or DBP lowering >10 mm Hg at week 12) was also nonsignificantly greater in both fimasartan groups (Fimasartan 60 mg, 81%; fimasartan 120 mg, 72%; candesartan 8 mg, 71%). The safety profile of the fimasartan 60 mg and 120 mg was similar to candesartan 8 mg, with a slightly higher, but statistically not significant, incidence of hepatic enzyme elevation in fimasartan 120 mg.

IMPLICATIONS

The antihypertensive effect of fimasartan, a newly available angiotensin II receptor type 1 blocker, is comparable, although not superior, to candesartan with a good safety profile. ClinicalTrials.gov identifier: NCT01135212.

The comparative efficacy and safety of the angiotensin receptor blockers in the management of hypertension and other cardiovascular diseases

All national guidelines for the management of hypertension recommend angiotensin receptor blockers (ARBs) as an initial or add-on antihypertensive therapy. The eight available ARBs have variable clinical efficacy when used for control of hypertension. Additive blood pressure-lowering effects have been demonstrated when ARBs are combined with thiazide diuretics or dihydropyridine calcium channel blockers, augmenting hypertension control. Furthermore, therapeutic use of ARBs goes beyond their antihypertensive effects, with evidence-based benefits in heart failure and diabetic renal disease particularly among angiotensin-converting enzyme inhibitor-intolerant patients. On the other hand, combining renin-angiotensin system blocking agents, a formerly common practice among medical subspecialists focusing on the management of hypertension, has ceased, as there is not only no evidence of cardiovascular benefit but also modest evidence of harm, particularly with regard to renal dysfunction. ARBs are very well tolerated as monotherapy, as well as in combination with other antihypertensive medications, which improve adherence to therapy and have become a mainstay in the treatment of stage 1 and stage 2 hypertension.

Effectiveness of angiotensin II receptor antagonists in a cohort of Dutch patients with type 2 diabetes mellitus (ZODIAC-14)

OBJECTIVE

There is limited evidence with respect to the between-group effects of various angiotensin receptor blockers (ARBs) on blood pressure and albuminuria in patients with type 2 diabetes mellitus. Therefore, we aimed to investigate the effects of differing ARBs on systolic blood pressure (SBP) and the albumin-creatinine ratio after 1 year in a large cohort of patients with type 2 diabetes mellitus.

METHODS

In 2007, 24 940 primary care patients with type 2 diabetes mellitus participated in the Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) study, a prospective observational cohort study. Patients were included in the current study if they were prescribed an ARB in 2007 and if 1-year follow-up data were available. The final study population comprised 3610 patients. Multivariate mixed-model analyses were performed to estimate effects of the various ARBs on SBP and albuminuria. Stratified subgroup analyses were performed according to baseline hypertension and albuminuria.

RESULTS

SBP decreased in all groups, the largest decrease being observed in the group receiving telmisartan. No significant or relevant changes over time were observed among groups for SBP and albuminuria. In the subgroup (n=1225) of normotensive patients, telmisartan was associated with a larger decrease in SBP after 1 year compared to other ARBs, without different effects on the albumin-creatinine ratio.

CONCLUSIONS

We observed no differences in effects on SBP and the albumin-creatinine ratio among differing ARBs in patients with type 2 diabetes mellitus.

Efficacy and tolerability of fimasartan, a new angiotensin receptor blocker, compared with losartan (50/100 mg): a 12-week, phase III, multicenter, prospective, randomized, double-blind, parallel-group, dose escalation clinical trial with an optional 12-week extension phase in adult Korean patients with mild-to-moderate hypertension

BACKGROUND

Angiotensin receptor blockers (ARBs) is an effective and well tolerated first-line antihypertensive drug. Fimasartan is a newly developed ARB that has not been compared with other ARBs with regard to its efficacy and tolerability.

OBJECTIVE

The goal of this study was to determine the noninferiority of fimasartan to losartan with regard to its efficacy and tolerability in adult Korean patients with mild-to-moderate hypertension.

METHODS

This was a randomized, multicenter, double-blind, parallel group, dose escalation, Phase III, noninferiority clinical trial. Patients aged 18 to 70 years with mild-to-moderate hypertension were randomized to receive either fimasartan 60/120 mg daily or losartan 50/100 mg daily with optional titration. Antihypertensive efficacy and tolerability were evaluated for 12 weeks. The primary end point was noninferiority of improvement in mean siDBP from baseline to week 12 for fimasartan compared with losartan. The incidence and severity of adverse events (AEs) and adverse drug reactions (ADRs) were evaluated to assess their tolerability. In addition, some patients whose blood pressure reached goal levels participated in a 24-week extension study for additional assessment of tolerability and efficacy.

RESULTS

Five hundred six patients were randomly allocated to receive fimasartan (n = 256) or losartan (n = 250). There was no significant difference in baseline demographic characteristics between the 2 treatment groups (fimasartan-treated group-mean age, 53.96 [8.79] years; mean weight, 70.58 [11.73] kg; male, 68.02%; losartan-treated group-mean age, 53.58 [9.61] years; mean weight, 69.80 [11.08] kg; male, 70.17%). At week 12, siDBP was significantly decreased from baseline in both groups (-11.26 [7.53] mm Hg in the fimasartan group and -8.56 [7.72] mm Hg in the losartan group [P < 0.0001]). The between-group difference was 2.70 mm Hg (P = 0.0002), and the lower limit of the 2-sided 95% CI (1.27 mm Hg) was higher than the prespecified noninferiority margin (-2.5 mm Hg). The incidence of ADRs were 7.84% and 10.40% in the fimasartan and losartan groups, respectively (χ(2) test, P = 0.3181). The efficacy of fimasartan was maintained over 24 weeks, and its tolerability was comparable with losartan in the extension study.

CONCLUSIONS

In this study with eligible adult Korean patients who had mild-to-moderate hypertension, the reduction of siDBP after 12 weeks of treatment with fimasartan 60/120 mg was noninferior to that of losartan 50/100 mg. By post hoc comparison, between-group differences in siDBP were significant in favor of fimasartan, suggesting superiority to losartan. There was no statistically significant difference in tolerability between the groups. This efficacy and tolerability were maintained throughout the additional 12-week extension study.

Benefits of once-daily therapies in the treatment of hypertension

In patients with hypertension, 24-hour blood pressure control is the major therapeutic goal. The number of daily doses is one characteristic of an antihypertensive agent that may affect the adequacy of 24-hour control. One measure of therapeutic coverage is the 24-hour trough-to-peak ratio, which determines the suitability of an agent for once-daily administration. The closer an agent is to a 100% trough-to-peak ratio, the more uniform the 24-hour coverage and therefore blood pressure control. High trough-to-peak ratio, long-acting antihypertensive medications lower blood pressure more gradually, which reduces the likelihood of adverse events attributable to abrupt drug action that occurs with shorter-acting agents. In hypertension, the natural diurnal variation of blood pressure may be altered, including elevated nighttime pressures. An optimal once-daily hypertension therapy would not only lower blood pressure but also normalize any blunted circadian variations in blood pressure. The benefits of once-daily agents with sustained therapeutic coverage may also be explained, in part, by increased patient adherence to simpler regimens as well as lower loss of blood pressure control during virtually inevitable intermittent noncompliance. Studies have demonstrated that once-daily antihypertensive agents have the highest adherence compared with twice-daily or multiple daily doses, including greater adherence to the prescribed timing of doses.

A systematic review and meta-analysis of candesartan and losartan in the management of essential hypertension

BACKGROUND

Candesartan is a relatively novel antihypertensive agent of the angiotensin receptor blocker (ARB). Several clinical trials have compared candesartan with losartan in the management of essential hypertension. However, systematic assessment of efficacy and safety between candesartan and losartan is still lacking.

METHODS

We reviewed randomised controlled trials (RCTs) comparing candesartan with losartan for net reduction in blood pressure from baseline, response and control rates, and incidences of common and serious adverse events.Weighted mean differences (WMD), and relative risk (RR) with 95% confidence intervals (CI) were calculated for continuous and dichotomous data, respectively.

RESULTS

A total of 12 RCTs with 3644 patients were included in this meta-analysis. When comparing the efficacy of candesartan and losartan in reducing systolic blood pressure (SBP) and diastolic blood pressure (DBP) at the end of the follow-up period, results with candesartan were superior to losartan in the reduction SBP and DBP (WMD, -2.97; 95% CI, -4.18 - -1.77; p < 0.001; WMD, -1.76; 95% CI, -2.57 - -0.96; p < 0.001; respectively). Candesartan had better response and control rates than losartan. (RR, 1.12; 95% CI, 1.06-1.18; p < 0.01; RR, 1.26; 95% CI, 1.06-1.50; p = 0.008). Reported common adverse events for the two agents were not significantly different (RR, 0.98; 95% CI, 0.86-1.12; p = 0.78). The incidence of serious adverse events for candesartan was lower than for losartan (RR, 0.48; 95% CI, 0.25-0.92; p = 0.03). The net reduction of DBP showed negative correlation with baseline DBP in both candesartan and losartan groups (regression coefficient -1.81, p = 0.03 and regression coefficient -1.56, p = 0.02, respectively).

CONCLUSIONS

Candesartan is superior to losartan in reducing blood pressure. Candesartan also causes fewer serious adverse events than losartan.

Comparative clinical- and cost-effectiveness of candesartan and losartan in the management of hypertension and heart failure: a systematic review, meta- and cost-utility analysis

The UK National Health Service (NHS) currently spends in excess of £250 million per annum on angiotensin II receptor blockers (ARBs) for the treatment of hypertension and heart failure; with candesartan currently dominating the market. With the recent introduction of generic losartan, we set out to directly compare the branded market leader to its now cheaper alternative. The primary objectives were to compare the blood pressure (BP) lowering efficacy and cardiovascular outcomes of candesartan and losartan in the treatment of essential hypertension and chronic heart failure, respectively. The secondary objective was to model their comparative incremental cost-effectiveness in a UK NHS setting. The Cochrane Central Register of Controlled Trials (Cochrane Library 2009, issue 2), which contains the Hypertension and Heart Group's specialist register, Medline (1950-February 2010), and Embase (1980-February 2010) were included in the search strategy. Selection criteria were randomised studies of candesartan versus losartan in adults (> 18 years). The main outcome measures were as follows: Hypertension: mean change from baseline in trough (24 h postdose) systolic and diastolic BP. Heart failure: composite of cardiovascular death and hospital admission for management of heart failure. Two reviewers applied inclusion criteria, assessed trial quality, and extracted data. Eight (three of which met inclusion criteria) and zero trials compared candesartan directly with losartan in the treatment of hypertension and heart failure, respectively. A between-treatment difference of -1.96 mmHg [95% confidence interval (CI) -2.40 to -1.51] for trough diastolic BP and -3.00 mmHg (95% CI -3.79 to -2.22) for trough systolic BP in favour of candesartan was observed. Based on this differential, a 10-year Markov model estimates the cost per quality-adjusted life-year gained to exceed £40,000 for using candesartan in place of generic losartan. Candesartan reduces BP to a slightly greater extent when compared with losartan, however, such difference is unlikely to be cost-effective based on current acquisition costs, perceived NHS affordability thresholds and use of combination regimens. We could find no robust evidence supporting the superiority of candesartan over losartan in the treatment of heart failure. We therefore recommend using generic losartan as the ARB of choice which could save the UK NHS approximately £200 million per annum in drug costs.

The therapeutic importance of home blood pressure assessment and combination antihypertensive therapy for achieving target blood pressure control: Ibaraki hypertension assessment trial

Tight blood pressure (BP) control is important for the prevention of cardiovascular disease in hypertensive patients. A cross-sectional study of 2339 patients from 101 clinics and hospitals in Ibaraki Prefecture was performed to evaluate BP control with the patients' current antihypertensive medication. Group A (n=892) included high-risk hypertensive patients with at least one of the following risk factors: diabetes mellitus, chronic kidney disease or a history of myocardial infarction. Group B (n=586) included patients <65 years old and Group C (n=859) included patients ≥65 years old. Both groups B and C included hypertensive patients without the above risk factors. A mean of 1.8±1.0 antihypertensive drugs per patient were prescribed. A total of 35.8% of all patients received monotherapy, 40% received a combination of three therapies and 20.3% received more than three kinds of drugs. The percentage of patients achieving the target BP at the office and at home was significantly higher in Group C than in the other groups (P<0.001). A combination of more than two antihypertensive drugs, including a high dose of either an angiotensin receptor blocker or a calcium channel blocker, was frequently prescribed to Group A to achieve the target office BP. Although the target BP should be lower in Group A (given their comorbidities), the absolute BP value and the number of medications were similar to the other groups. In conclusion, we demonstrated that physicians should treat hypertension more intensively with a combination of more than two antihypertensive drugs, using a high dose to achieve the target BP. In addition, it is important to teach hypertensive patients the clinical importance of monitoring their BP at home and the need to achieve home BP targets.

Update on the role of candesartan in the optimal management of hypertension and cardiovascular risk reduction

Hypertension is the most prevalent cardiovascular disease of adults and is a major risk factor for cardiovascular (CV) and cerebrovascular morbidity and mortality worldwide. Treatment of hypertension leads to reduction of CV morbidity and mortality through blood pressure reduction. The role of renin–angiotensin–aldosterone system (RAAS) in the pathophysiology of hypertension is mainly through generation of potent vasoconstrictor angiotensin II, stimulation of aldosterone secretion, and increase in sympathetic activation. Angiotensin II receptor blockers such as candesartan, a long-acting agent, alter this system by blocking the activation of angiotensin I receptors. Several important clinical trials have tested the efficacy of candesartan with placebo, antihypertensive agents, or other agents that block the RAAS for the control of hypertension and reduction of key CV risk factors such as microalbuminuria, heart failure, retinopathy, and carotid intima medial thickness. Candesartan has been shown to be a well-tolerated and effective antihypertensive agent with positive metabolic characteristics and additional benefits on CV and cerebrovascular outcomes. The aim of this review is to discuss the pharmacology, efficacy, and safety of candesartan, with an overview of key hypertension and CV studies involving candesartan.

Comparison of the efficacy of candesartan and losartan: a meta-analysis of trials in the treatment of hypertension

Informed by the findings from prospective observational studies and randomized outcome trials, guidelines for the management of hypertension acknowledge that the benefit of treatment can be attributed largely to blood pressure (BP) reduction. Therefore, quantification of differential BP lowering of different agents within classes of anti-hypertensives is of practical importance. The objective of this analysis was to compare the efficacy of candesartan and losartan with respect to reduction in systolic and diastolic BP (SBP and DBP). A systematic literature search of databases from 1980 to 1 October 2008 identified 13 studies in which candesartan and losartan were compared in randomized trials in hypertensive patients. Data from 4066 patients were included in the analysis using a random effect model. Mean changes in SBP and DBP were compared for each drug alone and after stratification for dose and for combination with hydrochlorothiazide (HCTZ). On the basis of all the data, the weighted mean difference favoured candesartan-3.22 mm Hg (95% confidence interval (CI) 2.16, 4.29) for SBP and 2.21 mm Hg (95% CI 1.34, 3.07) for DBP. These findings were consistent when analyses according to dose and combination with HCTZ were carried out. Thus, it can be concluded that at currently recommended doses, candesartan is more effective than losartan in lowering BP.

Comparative assessment of angiotensin receptor blockers in different clinical settings

Cardiovascular and renal disease can be regarded as progressing along a sort of continuum which starts with cardiovascular risk factors (hypertension, diabetes, dyslipidemia, smoking, etc), evolves with progression of atherosclerotic lesions and organ damage, and then becomes clinically manifest with the major clinical syndromes (myocardial infarction, stroke, heart failure, end-stage renal disease). The blood pressure control remains a fundamental mechanism for prevention of cardiovascular disease. The renin–angiotensin system is believed to play an important role along different steps of the cardiovascular disease continuum. Convincing evidence accumulated over the last decade that therapeutic intervention with angiotensin receptor blockers (ARBs) is effective to slow down or block the progression of cardiovascular disease at different steps of the continuum, with measurable clinical benefits. However, despite the shared mechanism of action, each ARB is characterized by specific pharmacological properties that may influence its clinical efficacy. Indeed, important differences among available ARBs emerged from clinical studies. Therefore, generalization of results obtained with a specific ARB to all available ARBs may be misleading. The present review provides a comparative assessment of the different ARBs in their efficacy on major clinical endpoints along the different steps of the cardiovascular disease continuum.

Effects of losartan vs candesartan in reducing cardiovascular events in the primary treatment of hypertension

Although angiotensin receptor blockers have different receptor binding properties no comparative studies with cardiovascular disease (CVD) end points have been performed within this class of drugs. The aim of this study was to test the hypothesis that there are blood pressure independent CVD-risk differences between losartan and candesartan treatment in patients with hypertension without known CVD. Seventy-two primary care centres in Sweden were screened for patients who had been prescribed losartan or candesartan between the years 1999 and 2007. Among the 24 943 eligible patients, 14 100 patients were diagnosed with hypertension and prescribed losartan (n=6771) or candesartan (n=7329). Patients were linked to Swedish national hospitalizations and death cause register. There was no difference in blood pressure reduction when comparing the losartan and candesartan groups during follow-up. Compared with the losartan group, the candesartan group had a lower adjusted hazard ratio for total CVD (0.86, 95% confidence interval (CI) 0.77–0.96, P=0.0062), heart failure (0.64, 95% CI 0.50–0.82, P=0.0004), cardiac arrhythmias (0.80, 95% CI 0.65–0.92, P=0.0330), and peripheral artery disease (0.61, 95% CI 0.41–0.91, P=0.0140). No difference in blood pressure reduction was observed suggesting that other mechanisms related to different pharmacological properties of the drugs may explain the divergent clinical outcomes.

Valsartan vs. other angiotensin II receptor blockers in the treatment of hypertension: a meta-analytical approach

OBJECTIVE

To compare the efficacy of valsartan in systolic (SBP) and diastolic blood pressure (DBP) reduction with other angiotensin II receptor blockers (ARBs) in essential hypertension.

METHODS

Systematic literature search of databases between October 1997 and May 2008. Meta-analysis of short-term, double-blind, parallel group, randomised controlled trials (RCTs) for treatment of adult hypertension (DBP: 90-115 mmHg). Random-effects meta-regression adjusting for baseline blood pressure (BP) was used to analyse the data. Mean change in SBP and DBP was estimated for each individual drug and dose combination.

RESULTS

In all, 31 RCTs (n = 13,110 patients) were included in the analysis. Six studies include trial arms with candesartan, six irbesartan, 13 losartan, two olmesartan, five telmisartan and 12 valsartan. The weighted average reduction in mean SBP and DBP for valsartan 160 mg was -15.32 mmHg (95% CI: -17.09, -13.63) and -11.3 mmHg (95% CI: -12.15, -10.52) and for 320 mg was -15.85 mmHg (95% CI: -17.60, -14.12) and -11.97 mmHg (95% CI: -12.81, -11.16); these are statistically significantly greater reductions compared with losartan 100 mg, which was -12.01 mmHg (95% CI: -13.78, -10.25) and -9.37 mmHg (95% CI: -10.18, -8.54) for SBP and DBP respectively. There is evidence that valsartan 160 mg reduces SBP and DBP more than irbesartan 150 mg and reduced DBP more than candesartan 16 mg. No other statistically significant difference in efficacy is demonstrated.

CONCLUSION

Valsartan administered at 160 or 320 mg is more effective at lowering BP than losartan 100 mg and shows comparable efficacy to other ARBs in patients with essential hypertension.

Effects of enalapril, candesartan or both on neurohumoral activation and LV volumes and function in patients with heart failure not treated with a beta-blocker

Background: The long-term effects of the angiotensin-receptor blocker candesartan, the angiotensin-converting enzyme inhibitor enalapril or their combination have been incompletely studied in a large cohort of patients with heart failure not treated with beta-blockers. The objective of this study was to investigate the changes in neurohormones and LV volumes and ejection fraction in patients treated with enalapril, candesartan, or enalapril plus candesartan without concomitant beta-blocker therapy.

Methods: Three hundred and ninety-two patients from the RESOLVD pilot study not treated with a beta-blocker at baseline or at any time during the trial were analyzed. Norepinephrine, endothelin-1, big endothelin-1, angiotensin-II, aldosterone, N-terminal proANP, BNP, and radionuclide angiography were measured before and after 43 weeks of treatment with candesartan alone ( n = 162), or enalapril alone ( n = 45), or candesartan plus enalapril ( n = 185). Endpoints were assessed at baseline and after 43 weeks of therapy.

Results: LV end-diastolic and end-systolic volumes increased significantly at 43 weeks in all groups except for patients treated with enalapril plus candesartan. BNP decreased at 43 weeks only in patients receiving dual angiotensin-II suppression (-6.1 ± 37.8 pmol/l). Angiotensin-II levels were significantly increased in patients treated with candesartan (+23.6 ± 47.1 pg/ml; p<0.05).

Conclusion: We conclude that angiotensin-II modulation, with enalapril and candesartan, without concomitant utilization of beta-blocker lead to a decrease in BNP and an attenuation of the increase in LV end-diastolic and end-systolic volumes without a reversal of this process in the long term.

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

Hypertension is a major health problem worldwide, yet remains under-diagnosed and under-treated. Angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) are highly effective at reducing blood pressure (BP), exhibit renoprotective properties and have placebo-like tolerability. However, it is unclear whether there are clinical differences in efficacy and tolerability between the available ARBs. A review of published, randomized, comparative clinical trials suggests that differences in BP-lowering efficacy and 24-hour BP control may exist between ARBs, although it appears that there is no evidence for important differences in tolerability between ARBs. Few studies have assessed attainment rates for important combined systolic BP (SBP)/diastolic BP (DBP) goals recommended in treatment guidelines. Likewise, few studies have directly compared more than two agents or ARB/hydrochlorothiazide fixed-dose combinations, and most ARBs have not been compared across their full recommended dosage ranges. Overall, there is insufficient weight of evidence to allow definitive conclusions to be drawn regarding the comparative efficacy of the available ARBs. However, newer ARBs (e.g. olmesartan medoxomil and telmisartan) appear to be more effective than older ARBs (e.g. losartan and valsartan) in reducing DBP and/or SBP in some trials. In addition, olmesartan medoxomil treatment regimens resulted in high BP control rates in several trials, but head-to-head trials with other ARBs are required to put these control rates into perspective, especially for SBP control with various agents. The purpose of this review is to present published data from ARB efficacy trials for a comparison of various efficacy parameters among the agents within this drug class.

Blood pressure lowering efficacy of angiotensin receptor blockers for primary hypertension

BACKGROUND

Angiotensin receptor blockers (ARBs) are widely prescribed for hypertension so it is essential to determine and compare their effects on blood pressure (BP), heart rate and withdrawals due to adverse effects (WDAE).

OBJECTIVES

To quantify the dose-related systolic and/or diastolic BP lowering efficacy of ARBs versus placebo in the treatment of primary hypertension.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2007, Issue 1), MEDLINE (1966 to February 2007), EMBASE (1988 to February 2007) and reference lists of articles.

SELECTION CRITERIA

Double-blind, randomized, controlled trials evaluating the BP lowering efficacy of fixed-dose monotherapy with an ARB compared with placebo for a duration of 3 to 12 weeks in patients with primary hypertension.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. WDAE information was collected from the trials.

MAIN RESULTS

Forty six RCTs evaluated the dose-related trough BP lowering efficacy of 9 ARBs in 13 451 participants with a baseline BP of 156/101 mm Hg. The data do not suggest that any one ARB is better or worse at lowering BP. A dose of 1/8 or 1/4 of the manufacturers' maximum recommended daily dose (Max) achieved a BP lowering effect that was 60 to 70% of the BP lowering effect of Max. A dose of 1/2 Max achieved a BP lowering effect that was 80% of Max. ARB doses above Max did not significantly lower BP more than Max. Due to evidence of publication bias, the largest trials provide the best estimate of the trough BP lowering efficacy for ARBs as a class of drugs: -8 mm Hg for SBP and -5 mm Hg for DBP. ARBs reduced BP measured 1 to 12 hours after the dose by about 12/7 mm Hg.

AUTHORS' CONCLUSIONS

The evidence from this review suggests that there are no clinically meaningful BP lowering differences between available ARBs. The BP lowering effect of ARBs is modest and similar to ACE inhibitors as a class; the magnitude of average trough BP lowering for ARBs at maximum recommended doses and above is -8/-5 mmHg. Furthermore, 60 to 70% of this trough BP lowering effect occurs with recommended starting doses. The review did not provide a good estimate of the incidence of harms associated with ARBs because of the short duration of the trials and the lack of reporting of adverse effects in many of the trials.

Relative Effects of Telmisartan, Candesartan and Losartan on Alleviating Arterial Stiffness in Patients with Hypertension Complicated by Diabetes Mellitus: An Evaluation Using the Cardio-Ankle Vascular Index (CAVI)

Using the cardio-ankle vascular index (CAVI) as an indicator, we assessed improvement of arterial stiffness in 95 outpatients with hypertension complicated by type 2 diabetes mellitus who were treated orally for ≤ 12 months with telmisartan 40 mg/day, losartan 50 mg/day or candesartan 8 mg/day. At 1 year, in the telmisartan and losartan groups CAVI did not change whereas in the candesartan group CAVI showed a statistically significant decrease of 2.70%. Although telmisartan is believed to enhance the activity of peroxisome proliferator-activated receptor (PPAR-γ) in vitro, it did not ameliorate arterial stiffness in our patients. Candesartan, however, improved arterial stiffness independently of blood pressure lowering and without PPAR-γ agonist action, possibly by direct action resulting from its potent affinity and binding capacity for the angiotensin II type 1 receptor. We conclude that candesartan is a potentially useful therapy against arterial stiffness in hypertensive patients with type 2 diabetes mellitus.

Cardiovascular drugs as antidiabetic agents: evidence for the prevention of type 2 diabetes

Given the long-term health consequences and increasing incidence of type 2 diabetes, there is great interest to potentially prevent or delay its onset. Primary prevention studies have demonstrated that intensive exercise and weight reduction, and to a lesser extent certain antidiabetic agents, can reduce new onset diabetes in at-risk individuals. Results from post hoc analyses and secondary end-point outcomes of large randomized controlled trials of cardiovascular drugs suggest that these may also have beneficial effects, reducing the incidence of new onset diabetes in addition to their proven cardiovascular benefits. Multiple meta-analyses confirm that drugs primarily acting on the renin-angiotensin system (RAS) reduce the incidence of diabetes in the populations studied, perhaps via improved insulin sensitivity and/or effects on pancreatic beta cells. However, results from the recent Diabetes REduction Approaches with Medication study specifically failed to show a significant reduction in the incidence of diabetes with ramipril in individuals with abnormal glucose tolerance at baseline. There is only limited evidence that statins improve glucose tolerance, and although beta-blockers tend to have detrimental effects on glucose tolerance, newer agents with vasodilatory properties may confer benefits. With current guidelines, the use of cardiovascular drugs modifying the RAS will increase in at-risk individuals, but at present, they cannot be recommended to prevent diabetes.

Updated meta-analytical approach to the efficacy of antihypertensive drugs in reducing blood pressure

BACKGROUND AND OBJECTIVE

Despite advances in the treatment of hypertension, control rates continue to be suboptimal in both Europe and the US. Strategies that improve hypertension control are therefore urgently needed. This study aimed to assess the relative efficacies of various antihypertensive drugs commonly used in France in reducing systolic and diastolic blood pressure (SBP and DBP) by using a meta-analytical approach. This update of a previously published meta-analytical approach extends the number of drugs evaluated from 13 to 19.

METHODS

A total of 80 randomised, controlled trials published between 1973 and 2007 involving 10 818 patients were selected for inclusion in the meta-analytical approach. Data were examined for 19 drugs, and 16 drugs were included in the analysis: hydrochlorothiazide, indapamide sustained-release (SR), atenolol, amlodipine, lercanidipine, manidipine, enalapril, ramipril, trandolapril, candesartan cilexetil, irbesartan, losartan, olmesartan medoxomil, telmisartan, valsartan and aliskiren. Weighted average reductions in SBP and DBP over a period of 8-12 weeks were calculated for each drug from information on both the mean and the variability in BP reduction. No trials evaluating furosemide, spironolactone or cicletanine satisfied the inclusion criteria for this analysis.

RESULTS

The average weighted reductions in SBP over 8-12 weeks were most marked with diuretics, and in particular indapamide SR 1.5 mg/day (mean change from baseline -22.2mm Hg), which reduced SBP to a greater extent than any of the other drugs evaluated (at any dosage considered). Average weighted reductions in DBP were generally similar with all classes of antihypertensives and ranged from -11.4mm Hg with the beta-adrenoceptor blocker atenolol and calcium channel antagonists to -10.3mm Hg with the angiotensin II type 1 receptor antagonists.

CONCLUSION

This new analysis supports the results of the earlier investigation, in that indapamide SR 1.5 mg/day appeared to be the most effective drug for producing significant reductions in SBP within 8-12 weeks, which is an essential element in optimising cardiovascular prevention among hypertensive patients. The clinical application of these results should take into consideration all the limitations discussed in this analysis.

Candesartan cilexetil--a review of effects on cardiovascular complications in hypertension and chronic heart failure

Therapeutic interventions that block the renin-angiotensin-aldosterone system (RAAS) have an important role in slowing the progression of cardiovascular risk actors to established cardiovascular diseases. In recent years, angiotensin receptor blockers (ARBs) have emerged as effective and well-tolerated alternatives to an angiotensin-converting enzyme inhibitor (ACEi) for RAAS blockade. The ARB candesartan was initially established as an effective once-daily antihypertensive treatment, providing 24-h blood pressure (BP) control with a trough:peak ratio close to 100%.

SCOPE

A Medline literature search was undertaken to identify randomised, controlled trials that examined the efficacy and cardiovascular outcomes associated with candesartan cilexetil in hypertension and chronic heart failure (CHF).

FINDINGS

Compared with other ARBs, candesartan demonstrates the strongest binding affinity to the angiotensin II type 1 receptor. Clinical trials have demonstrated that candesartan is well tolerated in combination with diuretics or calcium channel blockers (CCBs), making it a suitable treatment option for patients whose hypertension is not adequately controlled by monotherapy. Subsequently, candesartan became the only ARB licensed in the UK to treat patients with CHF and left ventricular ejection fraction < or = 40% as add-on therapy to an ACEi or when an ACEi is not tolerated. Studies in patients with symptomatic HF have indicated that candesartan treatment was associated with significant relative risk reductions in cardiovascular mortality and hospitalisation due to CHF.

CONCLUSIONS

There are clear indications that the clinical benefits of candesartan may extend beyond its proven antihypertensive effects to a wider range of complications across the cardiovascular continuum, including diabetes, left ventricular hypertrophy, atherosclerosis and stroke. Such results suggest that candesartan treatment may offer significant patient benefits as well as practical advantages over conventional treatment.

Angiotensin II Receptor Blockers for the Treatment of Heart Failure: A Class Effect?

STUDY OBJECTIVE

To examine the class effect of angiotensin II receptor blockers (ARBs) on mortality in patients with heart failure who were aged 65 years or older.

DESIGN

Retrospective population-based study.

DATA SOURCE

Administrative database that stores information on hospital discharge summaries for the Canadian provinces of Quebec, Ontario, and British Columbia.

PATIENTS

A total of 6876 patients aged 65 years or older who were discharged with a primary diagnosis of heart failure between January 1, 1998, and March 31, 2003, and who filled at least one prescription for an ARB within 90 days of discharge.

MEASUREMENTS AND MAIN RESULTS

Times to all-cause death in patients receiving individual ARBs were compared. Models were adjusted for demographic, clinical, physician, and hospital characteristics; models were also adjusted for dosage categories, which were represented by time-dependent variables. The cohort of 6876 patients had a mean +/- SD age of 78 +/- 7 years, and most (62%) were women. Losartan was the most frequently prescribed ARB (61%), followed by irbesartan (14%), valsartan (13%), candesartan (10%), and telmisartan (2%). Irbesartan, valsartan, and candesartan were associated with better survival rates than losartan (adjusted hazard ratios [HRs] and 95% confidence intervals [CIs] 0.65 [0.53-0.79], 0.63 [0.51-0.79], and 0.71 [0.57-0.90], respectively). No difference was noted in mortality in patients prescribed telmisartan compared with those receiving losartan (HR 0.92 [95% CI 0.55-1.54]).

CONCLUSIONS

Elderly patients with heart failure who were prescribed losartan had worse survival rates compared with those prescribed other commonly used ARBs. The absence of a class effect for ARBs is consistent with data showing pharmacologic differences among the drugs.

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.

A meta-analytical approach to the efficacy of antihypertensive drugs in reducing blood pressure

INTRODUCTION

Hypertension constitutes a veritable public health issue. Several classes of drugs are available for the treatment of hypertension. The objective of this meta-analytical approach was to assess the efficacy of antihypertensive drugs most commonly used in France in reducing clinical SBP and DBP.

METHODS

The antihypertensive drugs selected were hydrochlorothiazide, indapamide sustained release (SR), furosemide and spironolactone for diuretics; amlodipine and lercanidipine for calcium channel antagonists; atenolol for beta-adrenoceptor antagonists (beta-blockers); enalapril and ramipril for ACE inhibitors; and candesartan cilexetil, irbesartan, losartan, and valsartan for angiotensin II receptor antagonists. The trials selected were published between 1973 and 2004, evaluated monotherapy with trial drugs as fixed-dosage or with dosage increase, and assessed blood pressure reduction between 2 and 3 months. The analysis method used was based on the calculation of the sum weighted for the trial size.

RESULTS

A total of 72 trials (comprising 9094 patients) were selected and analyzed. No trial evaluating furosemide or spironolactone satisfied the inclusion criteria for this analysis. For SBP, the reduction was more marked with diuretics, calcium channel antagonists, and ACE inhibitors. Of all the drugs studied, indapamide SR gave the greatest SBP reduction (-22.2 mm Hg). Evaluated therapeutic classes had a similar magnitude of effect on DBP, i.e. reduction between -11.4 mm Hg with beta-adrenoceptor antagonists and -10.3 mm Hg with angiotensin II type 1 receptor antagonists.

CONCLUSION

Indapamide SR 1.5 mg appeared to be the most effective drug for a significant reduction in SBP within 2-3 months, which is an essential element in optimizing cardiovascular prevention among hypertensive patients. The clinical application of these results should take into consideration all the limitations discussed in this analysis.

A placebo-controlled comparison of the efficacy and tolerability of candesartan cilexetil, 8 mg, and losartan, 50 mg, as monotherapy in patients with essential hypertension, using 36-h ambulatory blood pressure monitoring

This double-blind, randomised, controlled study compared the efficacy of candesartan cilexetil 8 mg (n = 87) and losartan 50 mg (n = 89), once daily for 6 weeks, relative to placebo (n = 80) in patients with mild-to-moderate essential hypertension (diastolic blood pressure (DBP): 95-115 mmHg). Ambulatory BP measurements were done every 15 min over 36 h. At the end of the 6-week treatment, the mean change in DBP between the baseline and the 0-24-h period after the last dose of study medication was greater in patients receiving candesartan cilexetil 8 mg (-7.3 mmHg +/- 6.9 mmHg) compared with losartan 50 mg (-5.1 mmHg +/- 4.9 mmHg) (p < 0.05) or placebo (0.3 mmHg +/- 6.5 mmHg) (p < 0.001). The mean change in systolic BP (SBP) during this time was greater in patients receiving candesartan cilexetil 8 mg (-10.8 mmHg +/- 11.3 mmHg), or losartan 50 mg (-8.8 mmHg +/- 8.9 mmHg) than placebo (1.2 mmHg +/- 9.9 mmHg) (p < 0.001). Candesartan cilexetil 8 mg was associated with a greater reduction in DBP and SBP, relative to placebo, when compared with losartan 50 mg, during both daytime and night-time, and between 12 and 24 h after dosing (p < 0.001). Both active treatments were well tolerated. In patients with mild-to-moderate essential hypertension, candesartan cilexetil 8 mg therefore had greater, more consistent antihypertensive efficacy throughout the day and the night, and long-lasting efficacy after the last dose, compared with losartan 50 mg. This greater efficacy is maintained with an excellent tolerability associated with members of the angiotensin Il type 1-receptor blocker class.

Ambulatory blood pressure comparison of the anti-hypertensive efficacy of fixed combinations of irbesartan/hydrochlorothiazide and losartan/hydrochlorothiazide in patients with mild-to-moderate hypertension

This study examined whether the greater anti-hypertensive efficacy of irbesartan monotherapy over losartan monotherapy extends to the respective fixed-dose combinations with hydrochlorothiazide (HCTZ) in patients with mild-to-moderate hypertension. Patients were treated with either irbesartan 150 mg/HCTZ 12.5 mg or losartan 50 mg/HCTZ 12.5 mg over a 4-week period. Twenty-four hour daytime and night-time mean blood pressure (BP), BP load and duration of action were assessed using ambulatory BP monitoring. Both treatment regimens significantly reduced BP from baseline for all efficacy variables assessed. A significant difference was noted in adjusted mean changes from baseline in 24-h ambulatory diastolic BP with irbesartan/HCTZ versus losartan/HCTZ. Reduction in diastolic load was significantly greater with irbesartan/HCTZ than with losartan/HCTZ as was mean ambulatory systolic BP during the last 4 h of the dosing interval. Both regimens were well tolerated, with no significant differences in terms of adverse event profile observed. Irbesartan 150 mg/HCTZ 12.5 mg resulted in greater reductions in ambulatory BP than losartan 50 mg/HCTZ 12.5 mg.

A cost-utility analysis of losartan versus atenolol in the treatment of hypertension with left ventricular hypertrophy

INTRODUCTION

The LIFE (Losartan Intervention For Endpoint reduction in hypertension) study demonstrated a 13% relative risk reduction in the primary composite endpoint (myocardial infarction, stroke or death) for patients with hypertension and electrocardiographically diagnosed left ventricular hypertrophy (LVH) treated with losartan compared with atenolol. Losartan recipients also had a 25% relative risk reduction for stroke compared with atenolol recipients. Incorporating the results found in the LIFE study into an economic model, an incremental cost-effectiveness analysis was performed comparing losartan with atenolol in the treatment of 67-year old patients with hypertension and LVH.

METHODS

A Markov state transition model, based on published results of the LIFE trial (mean follow-up of 4.8 years), was utilised to extrapolate the outcomes observed in this trial to the patients' lifetime. Utility estimates for the associated health states were obtained from various published sources. Lifetime treatment costs were calculated adopting a societal perspective. Both costs and benefits were discounted and incremental cost-effectiveness ratios (ICERs) were estimated. One-way and probabilistic sensitivity analyses were performed.

RESULTS

The estimated ICER for losartan versus atenolol was 1337 Canadian dollars per QALY gained (1 Canadian dollar =0.75 US dollars, 2002 values). This ICER was robust to extensive sensitivity analysis, demonstrating a 95% probability that the ICER would be <20,000 Canadian dollars per QALY gained.

CONCLUSION

From a Canadian societal perspective, losartan appears to be a cost-effective alternative to atenolol in patients with hypertension and LVH. The estimated ICERs, including the sensitivity analyses, were within the range of cost-effectiveness ratios for various currently funded interventions and drugs in developed countries.

Patterns of antihypertensive therapy in new users of angiotensin II-receptor blockers

PURPOSE

The patterns of angiotensin II-receptor blocker (ARB) therapy in patients with and without a history of antihypertensive use were studied.

METHODS

Data for this retrospective cohort study were obtained from Caremark's data warehouse. Patients were included in the analysis if they filled prescriptions for ARBs only, did not receive ARB therapy within the 6 months before the filling of the first ARB prescription (index date), were continuously eligible for benefits for 6 months before the index date, were eligible for prescription benefits for the 12 months following the index date, and were age 20-80 years.

RESULTS

Of the 174,573 patients sampled, 53.4% were new to all antihypertensive therapies. Of the patients receiving an ARB, 67.9% received another antihypertensive during the evaluation period. Over 40% of patients new to all antihypertensive therapies had no other antihypertensive added to their ARB regimen. Of the patients with a history of antihypertensive use, 22.3% discontinued all antihypertensives before starting therapy with an ARB. Patients starting therapy with losartan and valsartan were less likely to be treated with mono-therapy and more likely to be treated with ARB-diuretic therapy than were patients starting therapy with telmisartan, irbesartan, or candesartan.

CONCLUSION

Patients who started antihypertensive therapy with ARBs tended to be new to antihypertensive therapy and, in a plurality of cases, continued to receive therapy with ARBs only. More than a fifth of patients who received antihypertensive therapy in the recent past were switched from that therapy to treatment with ARBs only. Treatment patterns differed by initial ARB used and the demographic profile of the patient.

Efficacy and safety of combination therapy using high- or low-dose hydrochlorothiazide with valsartan or other Angiotensin-receptor blockers

Only a minority of patients treated for hypertension achieve controlled blood pressure (BP) levels. Therapy with fixed-dose combinations of an angiotensinreceptor blocker (ARB) and low-dose hydrochlorothiazide (HCTZ) is commonly prescribed but not always sufficient to achieve the target BP. The efficacy and safety of the fixed-dose combination of valsartan 160 mg and HCTZ 25 mg was evaluated in patients in whom BP had not been controlled with a fixed-dose combination of another ARB and low-dose HCTZ (12.5 mg) in a multicenter trial. After a wash-out period for antihypertensive drugs, patients with a mean sitting diastolic BP (DBP) at trough (3)100 mm Hg but <110 mm Hg were treated with candesartan cilexetil 16 mg plus HCTZ 12.5 mg or telmisartan 80 mg plus HCTZ 12.5 mg for 4 weeks (phase 1). Patients whose BP was still uncontrolled (DBP (3)90 mm Hg) after 4 weeks of therapy were then given valsartan 160 mg plus HCTZ 25 mg for an additional 4 weeks (phase 2). The primary efficacy parameter was the reduction in DBP between week 4 and week 8 in the intention-to-treat (ITT) population. BP reduction during phase 1 was -14.3+/-11.3/-7.5+/-3.9 mm Hg. DBP was controlled in 26% of the patients after phase 1. In patients treated with valsartan 160 mg plus HCTZ 25 mg during phase 2, DBP decreased by an additional 10.3+/-6.5 mm Hg and the mean sitting systolic BP (SBP) by an additional 11.0+/-11.7 mm Hg. The additional decrease was significant (P<.0001) for both parameters and independent of the fixed-dose combination used during phase 1. Among patients whose BP remained uncontrolled during phase 1, 74% achieved a controlled DBP after phase 2. The incidence of adverse events during both phases was comparably low and the results of laboratory tests were unremarkable. Treatment with valsartan 160 mg/HCTZ 25 mg offered a substantial benefit for patients with hypertension not controlled with the combination of candesartan cilexetil 16 mg or telmisartan 80 mg and low dose HCTZ, while maintaining a comparable safety and tolerability profile.

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 losartan on diabetic maculopathy in type 2 diabetic patients: a randomized, double-masked study

OBJECTIVE

Diabetic maculopathy (DMa) is a leading cause of visual loss in the western world. Preliminary studies have suggested that angiotensin converting enzyme inhibitors might be effective in preventing the progression of diabetic retinopathy, but no studies have quantitatively assessed the effect of this treatment on macular oedema in patients with DMa. We evaluated the effect of treatment with the angiotensin II receptor antagonist losartan on macular oedema and hard exudates in patients with an advanced stage of DMa.

DESIGN

Randomized, placebo-controlled, double-masked and parallel-group trial.

SETTING

Academic medical centre.

SUBJECTS

Twenty-four type 2 diabetic patients with DMa.

INTERVENTION

Subjects were randomly assigned to a 4-month treatment with either losartan (50 mg o.d.) or placebo.

MAIN OUTCOME MEASURES

(i) Degree of macular oedema as estimated by optical coherence tomography scanning of the retina; (ii) fundus photography and flourescein angiography; (iii) 24-h ambulatory blood pressure (BP); (iv) urinary albumin excretion (UAE); and (v) transcapillary escape rate of albumin (TERalb).

RESULTS

Central retinal thickness increased from 244 +/- 16 to 256 +/- 31 microm in the losartan group, whilst there was no change in the placebo group (245 +/- 36 microm vs. 242 +/- 30 microm), P = 0.017. Day BP were lowered in the losartan group (from 144/83 +/- 17/10 to 138/78 +/- 20/11 mmHg) compared with the placebo group (140/81 +/- 14/5 to 139/82 +/- 13/9 mmHg), P = 0.27 for systolic and P = 0.009 for diastolic BP. Importantly, there were no changes in night BP in any of the groups. We found no changes in the number of hard exudates, semiquantitative retinopathy grade, visual acuity, UAE, or TERalb in any of the groups.

CONCLUSIONS

Type 2 diabetic patients with maculopathy do not seem to benefit from short-term treatment with losartan (50 mg once daily) as far as retinal thickness is concerned, as this dose may increase retinal thickness in the central macular area. Long-term studies are required to assess the clinical implications of these findings.

Clinical comparative trials of angiotensin II type 1 (AT1)-receptor blockers

Three characteristics of antihypertensive medication are pivotal in therapy for a patient with hypertension: potency and efficacy, duration of action, and the incidence of side-effects. The relatively new class of AT1-receptor blockers all display placebo-like tolerability and, as a class, their antihypertensive efficacy compares well with other antihypertensive classes. However, it is unclear whether clinically important differences in duration of action and antihypertensive efficacy exist within the AT1-receptor blocker class itself. The results of a number of head-to-head clinical comparisons between these agents suggest that candesartan cilexetil and irbesartan may be more effective than the prototype AT1-receptor blocker, losartan. In addition, studies using ambulatory blood pressure recording techniques have clarified the relative durations of antihypertensive action of the AT1-receptor blockers. In particular, studies mimicking the common event of a missed or delayed dose of antihypertensive medication, show that the antihypertensive effect of candesartan cilexetil extends well beyond the 24-h dosing interval, while the effect of losartan declines rapidly over this period. The available evidence therefore suggests that significant differences in efficacy and duration of action are apparent within the AT1-receptor blocker class, and that these differences may well translate into clinically relevant differences in cardiovascular outcome.