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.

Combination therapy of olmesartan and azelnidipine inhibits sympathetic activity associated with reducing oxidative stress in the brain of hypertensive rats

It has been demonstrated that the antihypertensive drugs with the antioxidant action on the brainstem inhibit the sympathetic activity and consequently decrease blood pressure and heart rate (HR) in hypertensive rats. Combination drugs of the angiotensin receptor blocker and calcium channel blocker, such as olmesartan (OLM)/azelnidipine (AZ) and candesartan (CAN)/amlodipine (AM), are widely used for treating hypertension in Japan. In this study, it was investigated whether there are differences in the antioxidant effect in the brain and the sympathoinhibitory effect between OLM/AZ and CAN/AM combination therapies in stroke-prone spontaneously hypertensive rats (SHRSP). OLM/AZ (10/8 mg kg(-1) day(-1)), CAN/AM (4/2.5 mg kg(-1) day(-1)), or vehicle was orally administered for 30 days to SHRSP. OLM/AZ and CAN/AM markedly decreased systolic blood pressure to the same extent. OLM/AZ decreased HR to a greater extent than CAN/AM. Urinary norepinephrine excretion as a marker of sympathetic activity was unchanged in the CAN/AM group, but reduced in the OLM/AZ group. Oxidative stress in the whole brain assessed using the in vivo electron spin resonance method was similarly decreased in both OLM/AZ and CAN/AM groups. Importantly, thiobarbituric acid reactive substance levels in the brainstem were significantly lower in the OLM/AZ group, but not in the CAN/AM group, than in the vehicle group. These results suggest that combination therapy of either OLM/AZ or CAN/AM does not induce reflex-mediated sympathetic activation despite the marked blood pressure reduction, which is associated with an antioxidant effect in the brain regions affecting the sympathetic activity. Furthermore, the antioxidant effect in the brainstem and the sympathoinhibitory effect of OLM/AZ combination may be greater than those of CAN/AM combination treatment.

Blood pressure lowering efficacy of diuretics as second-line therapy for primary hypertension

BACKGROUND

Diuretics are widely prescribed for hypertension not only as a first-line drug but also as a second-line drug. Therefore, it is essential to determine the effects of diuretics on blood pressure (BP), heart rate and withdrawals due to adverse effects (WDAEs) when given as a second-line drug.

OBJECTIVES

To quantify the additional reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP) of diuretic therapy as a second-line drug in patients with primary hypertension

SEARCH STRATEGY

CENTRAL (The Cochrane Library 2008, Issue 2), MEDLINE (1966-July 2008), EMBASE (1988-July 2008) and bibliographic citations of articles and reviews were searched.

SELECTION CRITERIA

Double-blind, randomized, controlled trials evaluating the BP lowering efficacy of a diuretic in combination therapy with another class of anti-hypertensive drugs compared with the respective monotherapy (without a diuretic) for a duration of 3 to 12 weeks in patients with primary hypertension.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted the data and assessed trial quality.

MAIN RESULTS

Fifty-three double-blind RCTs evaluating a thiazide in 15129 hypertensive patients (baseline BP of 156/101 mmHg) were included. Hydrochlorothiazide was the thiazide used in 49/53 (92%) of the included studies. The additional BP reduction caused by the thiazide as a second drug was estimated by comparing the difference in BP reduction between the combination and monotherapy groups. Thiazides as a second-line drug reduced BP by 6/3 and 8/4 mmHg at doses of 1 and 2 times the manufacturer's recommended starting dose respectively. The BP lowering effect was dose related. The effect was similar to that obtained when thiazides are used as a single agent. Only 3 double-blind RCTs evaluating loop diuretics were identified. These RCTs showed a BP lowering effect of a starting dose of about 6/3 mmHg.

AUTHORS' CONCLUSIONS

Thiazides when given as a second-line drug have a dose related effect to lower blood pressure that is similar to when they are added as a first-line drug. This means that the BP lowering effect of thiazides is additive. Loop diuretics appear to have a similar blood pressure lowering effect as thiazides at 1 times the recommended starting dose. Because of the short duration of the trials and lack of reporting of adverse events, this review does not provide a good estimate of the incidence of adverse effects of diuretics given as a second-line drug.

The effects of replacing dihydropyridine calcium‐channel blockers with angiotensin II receptor blocker on the quality of life of hypertensive patients

Hypertension is a major risk factor for cardiovascular events and the goal of treating hypertension is to prevent complications due to these events. However, some other properties, including few side-effects and improvement of the quality of life (QOL), are desirable in a drug as well as its antihypertensive effect. Dehydropydine calcium-channel blockers (DCCBs) are the most frequently used antihypertensive agents in Japan. The antihypertensive effect of DCCBs is satisfactory, but side-effects, e.g. nocturia, flushing and palpitations, are a problem. The aim was to evaluate the effects of a change of treatment from DCCBs on the QOL of hypertensive patients. An open study was performed to evaluate the effects of switching treatment from DCCBs to angiotensin II receptor blocker (ARB) therapy on the QOL of hypertensive patients. The ARBs have been reported to be effective and well-tolerated antihypertensive drugs. Candesartan cilexetil was selected because it is the most frequently used ARB in Japan. One hundred patients with mild to moderate hypertension, being treated with DCCBs, were randomly selected to receive candesartan cilexetil (8-12 mg once a day). The patients were followed for 3 months, while blood pressure (BP), side-effects and QOL were monitored. BP was equally well controlled before and after the change of antihypertensive therapy. The candesartan cilexetil-treated patients exhibited improvement of several aspects of QOL, including general symptoms, physical symptoms and well-being, work and satisfaction and sleep scale. Emotional state and cognitive function also improved. Patients aged 65 years or younger achieved significant improvement of sexual function. Changing treatment from DCCBs to ARB therapy achieved equal BP control with a lower drug dose. Moreover, the change to cadesartan cilexetil had a positive impact on the QOL.

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.

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.

Amlodipine Besylate versus Candesartan Cilexetil in Hypertensive Patients - Office and Self-Measured Blood Pressure : A Randomised, Double-Blind, Comparative, Multicentre Trial

OBJECTIVE

The aim of this study was to compare the antihypertensive efficacy and tolerability of the calcium channel antagonist amlodipine besylate versus the angiotensin II type 1 receptor antagonist candesartan cilexetil in hypertensive patients.

PATIENTS AND METHODS

After a 2-week placebo washout period, 326 patients with essential hypertension were randomised to receive amlodipine 5mg once daily or candesartan cilexetil 8mg once daily in a double-blind, parallel-group design with a 12-week active treatment period followed by a 4-day placebo drug-free period. The initial daily dose could be doubled at week 6 if office diastolic blood pressure (DBP) was still >/=90mm Hg. BP changes were assessed daily through patient self-measurements, and fortnightly by office BP measurements.

RESULTS

A total of 294 patients (151 amlodipine and 143 candesartan cilexetil) were included in the per-protocol analysis of the primary endpoint of BP change from baseline at 12 weeks. Reductions in sitting office systolic BP (SBP) [amlodipine 24.4mm Hg, candesartan cilexetil 22.3mm Hg] and DBP (amlodipine 14.9mm Hg, candesartan cilexetil 14.8mm Hg) were statistically equivalent within the chosen range of equivalence (5mm Hg for SBP and 3mm Hg for DBP). The proportion of controlled patients (office BP <140/90mm Hg) at the end of therapy was similar in both treatment groups (amlodipine 46.9%, candesartan cilexetil 44.4%). The reduction in self-measured DBP was significantly greater (p < 0.05) for amlodipine (7.2mm Hg) compared with candesartan cilexetil (4.8mm Hg). There was no significant difference between the two treatments in the incidence of adverse events reported.

CONCLUSIONS

Amlodipine besylate and candesartan cilexetil were both very effective in lowering office BP after 12 weeks of treatment. There was a trend towards a better self-measured BP reduction with amlodipine compared with candesartan cilexetil. The overall incidence of adverse events was comparable between the two treatments.

Current and future uses of candesartan in the treatment of heart failure

Candesartan is an angiotensin receptor antagonist that is long acting, well absorbed from the gastrointestinal tract and demonstrates an insurmountable receptor antagonism. It is an effective once-daily antihypertensive therapy that maintains good control of blood pressure for over 24 h. More recently, candesartan was shown to be an effective therapy for heart failure patients, producing a significant reduction in mortality and morbidity. Importantly, the studies have demonstrated that candesartan is effective in heart failure patients intolerant to angiotensin-converting enzyme inhibitors (ACE-I), as well as in addition to ACE-I. This paper reviews the data supporting the use of candesartan to treat patients with clinical heart failure.

Candesartan cilexetil: a pharmacoeconomic review of its use in chronic heart failure and hypertension

The addition of candesartan cilexetil (Atacand, Amias, Blopress, Kenzen, Ratacand) to standard therapy for chronic heart failure (CHF) provided important clinical benefits at little or no additional cost in France, Germany and the UK, according to a detailed economic analysis focusing on major cardiovascular events and prospectively collected resource-use data from the CHARM-Added and CHARM-Alternative trials in patients with CHF and left ventricular (LV) systolic dysfunction. Results of a corresponding cost-effectiveness analysis showed that candesartan cilexetil was either dominant over placebo or was associated with small incremental costs per life-year gained, depending on the country and whether individual trial or pooled data were used. Preliminary data from a US cost-effectiveness analysis based on CHARM data also showed favourable results for candesartan cilexetil. Two cost-effectiveness analyses of candesartan cilexetil in hypertension have been published, both conducted in Sweden. Data from the SCOPE trial in elderly patients with hypertension, which showed a significant reduction in nonfatal stroke with candesartan cilexetil-based therapy versus non-candesartan cilexetil-based treatment, were incorporated into a Markov model and an incremental cost-effectiveness ratio of euro12 824 per QALY gained was calculated (2001 value). Another modelled cost-effectiveness analysis of candesartan cilexetil was based on the ALPINE trial, in which the incidence of new-onset diabetes was significantly lower in patients with newly diagnosed hypertension who were randomised to candesartan cilexetil (with or without felodipine) than among those who received hydrochlorothiazide (with or without atenolol). Although candesartan cilexetil was dominant over hydrochlorothiazide, the ALPINE cost-effectiveness analysis relied on a small number of clinical events and did not evaluate the incremental cost of candesartan cilexetil per life-year or QALY gained. In conclusion, despite some inherent limitations, economic analyses incorporating CHARM data and conducted primarily in Europe have shown that candesartan cilexetil appears to be cost effective when added to standard CHF treatment in patients with CHF and compromised LV systolic function. The use of candesartan cilexetil as part of antihypertensive therapy in elderly patients with elevated blood pressure was also deemed to be cost effective in a Swedish analysis, primarily resulting from a reduced risk of nonfatal stroke (as shown in the SCOPE study); however, the generalisability of results to other contexts has not been established. Cost-effectiveness analyses comparing candesartan cilexetil with ACE inhibitors or other angiotensin receptor blockers in CHF or hypertension are lacking, and results reported for candesartan cilexetil in a Swedish economic analysis of ALPINE data focusing on outcomes for diabetes require confirmation and extension.

Efficacy and tolerability of candesartan cilexetil vs. amlodipine as assessed by home blood pressure in hypertensive patients

This randomised, double-blind study compared the anti-hypertensive efficacy and tolerability of Candesartan cilexetil (CC 8-16 mg) and Amlodipine (AML 5-10 mg) on home blood pressure (HBP) measurements in mild-to-moderate hypertensive patients. After a 2-week wash-out, patients aged 18-74 years, with a sitting diastolic blood pressure (sDBP)=95-115 mmHg, untreated or intolerant to therapy or uncontrolled were randomised to CC 8 mg or AML 5 mg O.D. for 12 weeks (W12). Patients not normalised or not responders at W12 had their dose doubled for the remaining 6 weeks. HBP was measured before each visit, during 5 days (three measurements in the morning, 24 h after last dose and before drug intake and three measurements before bedtime). The primary criterion was the comparison of mean morning sDBP at baseline and post-treatment. A total of 638 patients were enrolled, 540 of whom were randomised to CC or AML. The intent-to-treat and safety analyses were performed in 532 patients while 321 constituted the per protocol population. Baseline characteristics and BP values of the two groups were similar. Morning sDBP did not differ between groups at W12, but AML patients had significantly more adverse events (AEs) than those treated by CC (28 vs. 20%, p=0.03); 6% of AML patients vs. 1% of CC patients were withdrawn due to AEs (p=0.009). CC demonstrates a better tolerability over AML and an equivalent anti-hypertensive efficacy in terms of morning home DBP after 12 weeks of treatment.

Angiotensin receptor blockade in the challenging era of systolic hypertension

Systolic blood pressure is a major cardiovascular risk factor which is often associated with arterial stiffness. Markers of arterial stiffness, such as pulse pressure and carotid-femoral pulse wave velocity, have been proved independent predictors of cardiovascular risk. Recent evidence suggests that the renin-angiotensin system is involved in the pathogenesis of systolic hypertension and arterial stiffness. Outcome trials have shown impressive cardiovascular protection by reducing systolic blood pressure (BP) with drug treatment. However, in clinical practice systolic hypertension remains largely uncontrolled, first, because systolic BP goal is more difficult to be reached than diastolic and, second, because physicians are often reluctant to intensify treatment in patients with systolic BP close to 150 mmHg. Recent trials have focused on the effects of antihypertensive drugs not only on blood pressure, but also on pulse pressure and pulse-wave velocity. Blockade of the renin-angiotensin-aldosterone system, using angiotensin-converting enzyme inhibitors and more recently angiotensin receptor blockers, has been shown to provide beneficial effects on arterial stiffness that appear to be independent of their antihypertensive effects. Recent outcome trials have shown significant cardiovascular protection with angiotensin receptor blockers. These drugs have an excellent placebolike profile of adverse effects which is maintained when these drugs are combined with low-dose diuretics. Therefore, an angiotensin receptor blocker-based treatment strategy appears to be an attractive and evidence-based approach for the management of systolic hypertension, the reduction of arterial stiffness and the prevention of cardiovascular disease.

Effect of amlodipine on systolic blood pressure

BACKGROUND

Systolic hypertension is the most common form of hypertension, particularly in people aged >60 years. Caused by decreased compliance of large arteries, systolic hypertension is an independent risk factor for cardiovascular disease. Recent studies have demonstrated that it is more important to control systolic blood pressure (SBP) than diastolic blood pressure (DBP).

OBJECTIVE

The objective of this study was to perform a systematic literature review to examine the effectiveness of amlodipine in lowering SBP in a variety of patient subgroups and clinical settings.

METHODS

The literature review methodology included identifying, selecting, appraising, extracting, and synthesizing primary research studies. Following an a priori protocol, published literature was searched from 1980 to 2001 using 3 electronic databases. A manual review of the reference lists of recent review articles and all accepted studies was performed. Parallel-group, randomized, controlled trials that included at least 10 adults with baseline hypertension (SBP>or=140 mm Hg, DBP>or=90 mm Hg, or both), included at least 1 arm randomized to initial treatment with amlodipine monotherapy, had a minimum treatment duration of 8 weeks, and reported baseline and end-point blood pressure were included.

RESULTS

Of 696 citations identified, 85 primary studies met all inclusion criteria. Comparable treatment arms were pooled, and weightd mean SBP was calculated. In the amlodipine monotherapy arms, which included >5000 patients, SBP decreased by a mean of 17.5 mm Hg from baseline. The effect of amlodipine in reducing SBP was greater in elderly patients (age>or=60 years) and patients with author-defined isolated systolic hypertension. The dose was titrated to achieve the target blood pressure in 73 of 89 amlodipine treatment arms, whereas 16 treatment arms reported fixed doses. The median daily dose was 5 mg (range, 1.25-15 mg) in both the fixed-dose and dose-titration groups.

CONCLUSIONS

In this review of the published literature, amlodipine monotherapy was effective in reducing SBP. Antihypertensive agents such as amlodipine warrant consideration for the management of patients with inadequately controlled SBP.

Candesartan cilexetil: an update of its use in essential hypertension

Candesartan cilexetil is converted to the angiotensin II receptor antagonist candesartan during absorption from the gastrointestinal tract. The selective and competitive binding of candesartan to the angiotensin II type 1 (AT(1)) receptor prevents binding of angiotensin II, a key mediator in the renin-angiotensin system. Significant reductions in systolic BP and diastolic BP are achieved with a once-daily dosage of candesartan cilexetil 2 to 32 mg/day in patients with mild to moderate hypertension. In randomised studies, candesartan cilexetil 8 to 16 mg/day was at least as effective as therapeutic dosages of losartan or other angiotensin II receptor antagonists. At a dosage of up to 32 mg/day candesartan cilexetil demonstrated greater antihypertensive efficacy than losartan 50 or 100 mg/day. In comparative trials, candesartan cilexetil demonstrated similar or greater antihypertensive efficacy compared with enalapril or hydrochlorothiazide and equivalent efficacy compared with amlodipine. The efficacy of candesartan cilexetil is not affected by age, and the drug provided significant BP reductions in Black patients and in those with severe hypertension. Long-term clinical studies to assess the effects of treatment with candesartan cilexetil on cardiovascular morbidity and mortality are ongoing. Regression of left ventricular hypertrophy has been seen with candesartan cilexetil treatment in patients with hypertension. Furthermore, the drug has favourable effects on renal function in patients with hypertension with or without coexisting diabetes mellitus. Renal vascular resistance and albumin excretion were reduced following treatment with candesartan cilexetil. Glucose homeostasis and lipid metabolism were not affected by treatment in patients with type 2 diabetes mellitus. Candesartan cilexetil is well tolerated and is not associated with cough, a common adverse effect of angiotensin converting enzyme inhibitor treatment. A pooled analysis of clinical trials found that the tolerability profile of candesartan cilexetil is not significantly different from that of placebo. Adverse events are not dose-related and are generally of mild to moderate severity.

CONCLUSIONS

Candesartan cilexetil is an effective antihypertensive agent with a tolerability profile similar to that of placebo. Comparative data indicate that candesartan cilexetil has antihypertensive efficacy equivalent to that of other major classes of antihypertensive agents and has a long duration of action. Therefore, candesartan cilexetil is a useful therapeutic option in the management of patients with hypertension.

Combination therapy with AT(1)-receptor blockers

Although current hypertension management guidelines recommend increasingly stringent blood pressure targets, these targets are seldom achieved in clinical practice. Even in patients with mild-to-moderate hypertension, monotherapy is only effective in approximately 50-70% of patients, and thus there is a clear need for combination therapy if stringent blood pressure targets are to be achieved. Drugs used in combination therapy should satisfy a number of prerequisites, including complementary mechanisms of action, enhanced efficacy in combination, and maintained (or improved) tolerability. Evidence is accumulating that combination therapy with an AT(1)-receptor blocker and a diuretic represents a rational and effective treatment option. In clinical trials, the combination of candesartan cilexetil, 16 mg, and hydrochlorothiazide, 12.5 mg, has been shown to be more effective in lowering blood pressure than either agent alone. Furthermore, this combination has been shown to reduce blood pressure to a greater extent, and control blood pressure in a higher proportion of patients, than the combination of losartan, 50 mg, and hydrochlorothiazide, 12.5 mg, both when used instead of or in addition to previous antihypertensive therapy. The placebo-like tolerability of AT(1)-receptor blockers was maintained when these drugs were used in combination with hydrochlorothiazide. The combination of candesartan and a dihydropyridine calcium antagonist has also been shown to be more effective than either component alone. Furthermore, in the Candesartan and Lisinopril Microalbuminuria (CALM) Study, the combination of candesartan and lisinopril reduced blood pressure to a greater extent than either agent alone, and tended to have a greater effect on microalbuminuria.