Antihypertensive efficacy and safety of losartan alone and in combination with hydrochlorothiazide in adult African Americans with mild to moderate hypertension

A Comparative Study of the Safety and Efficacy Between Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers on the Management of Hypertension: A Systematic Review

Renin-angiotensin-aldosterone system (RAAS) inhibitors, including angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), are commonly used in the management of hypertension. High blood pressure is a vital risk factor for cardiovascular disease. This study aims to establish any significant difference in using ACEIs and ARBs in managing hypertension. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to conduct this systematic review. We searched PubMed, MEDLINE, and ScienceDirect for articles published in the last 20 years (2003 to 2023). Our search was last done on the 27th of June, 2023. Following the initial search, 8,313 articles were found on PubMed. After screening the articles selected from the databases, 10 articles examining 1,621,445 patients were selected for the final study. Three articles were identified that compared ACEI and ARB in their capacity to lower blood pressure. Six articles compared both medications' capacity to reduce cardiovascular events and mortality. Five articles were identified that compared both classes of drugs for adverse effects. This study was made to determine whether or not there is a difference between the use of ACEIs and ARBs in the treatment of hypertension. The study showed that both ACEIs and ARBs are similar in their efficacy in lowering blood pressure. However, ACEI was revealed to be superior to ARB in reducing cardiovascular events and all-cause mortality. ARB was shown to be better tolerated by patients than ACEI.

Oral combined hydrochlorothiazide and lisinopril vs nifedipine for postpartum hypertension: a comparative-effectiveness pilot randomized controlled trial

BACKGROUND

Angiotensin-converting enzyme inhibitors and diuretics may be underutilized for postpartum hypertension because of their teratogenicity during pregnancy.

OBJECTIVE

We evaluated whether combined oral hydrochlorothiazide and lisinopril therapy produced superior short-term blood pressure control when compared with nifedipine among postpartum individuals with hypertension requiring pharmacologic treatment.

STUDY DESIGN

We performed a pilot randomized controlled trial (October 2021 to June 2022) that included individuals with chronic hypertension or hypertensive disorders of pregnancy with 2 systolic blood pressure measurements ≥150 mm Hg and/or diastolic blood pressure measurements ≥100 mm Hg within 72 hours after delivery. Participants were randomized to receive either combined hydrochlorothiazide and lisinopril therapy or nifedipine therapy after stratifying the participants by diagnosis (chronic hypertension vs hypertensive disorders of pregnancy). The primary outcome was stage 2 hypertension (systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg) determined using a home blood pressure monitor on days 7 to 10 after delivery or at readmission to the hospital for blood pressure control. The secondary outcomes included severe maternal morbidity (any of the following: intensive care unit admission; hemolysis, elevated liver enzymes, low platelet count syndrome; eclampsia; stroke; cardiomyopathy; or maternal death), need for intravenous medications after randomization, hospital length of stay, blood pressure during first clinic visit, medication compliance, and adverse events. A pilot trial with 70 individuals was planned given the limited available data on combined hydrochlorothiazide and lisinopril therapy use in postpartum care. We calculated relative risks and 95% credible intervals in an intention-to-treat analysis. Finally, we conducted a preplanned Bayesian analysis to estimate the probability of benefit or harm with a neutral informative prior.

RESULTS

Of 111 eligible individuals, 70 (63%) agreed and were randomized (31 in the hydrochlorothiazide and lisinopril group and 36 in the nifedipine group; 3 withdrew consent after randomization), and the characteristics were similar at baseline between the groups. The primary outcome was unavailable for 9 (12.8%) participants. The primary outcome occurred in 27% of participants in the hydrochlorothiazide and lisinopril group and in 43% of the participants in the nifedipine group (posterior adjusted relative risk, 0.74; 95% credible interval, 0.40-1.31). Bayesian analysis indicated an 85% posterior probability of a reduction in the primary outcome with combined hydrochlorothiazide and lisinopril therapy relative to nifedipine treatment. No differences were noted in the secondary outcomes or adverse medication events.

CONCLUSION

The results of the pilot trial suggest a high probability that combined hydrochlorothiazide and lisinopril therapy produces superior short-term BP control when compared with nifedipine. These findings should be confirmed in a larger trial.

A Review of ACE Inhibitors and ARBs in Black Patients With Hypertension

Objective: To review current guidelines and recent data evaluating the efficacy and safety of angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) in black hypertensive patients. Data Sources: Articles evaluating race-specific outcomes in hypertension were gathered using a MEDLINE search with keywords black, African American, ACE inhibitor, angiotensin receptor blocker, angiotensin system, and hypertension. Studies published from 2000 through April 2018 were reviewed. Study Selection and Data Extraction: Six guidelines, 8 monotherapy publications, and 5 combination therapy publications included race-specific results and were included in the review. The authors individually compared and contrasted the results from each publication. Data Synthesis: Numerous monotherapy trials indicate that black patients may have a reduced blood pressure (BP) response with ACE inhibitors or ARBs compared with white patients. Conversely, additional studies propose that race may not be the primary predictor of BP response. Reduced efficacy is not observed in trials involving combination therapy. Some studies suggest increased cardiovascular and cerebrovascular morbidity and mortality with ACE inhibitor or ARB monotherapy in black patients; however, data are conflicting. Relevance to Patient Care and Clinical Practice: This article clarifies vague guideline statements and informs clinicians on the appropriate use of ACE inhibitors or ARBs for hypertension treatment in black patients through an in-depth look into the evidence. Conclusions: Potentially reduced efficacy and limited outcomes data indicate that ACE inhibitors or ARBs should not routinely be initiated as monotherapy in black hypertensive patients. Use in combination with a calcium channel blocker or thiazide diuretic is efficacious in black patients, and there are no data showing that this increases or decreases cardiovascular or cerebrovascular outcomes.

Synthesis and Evaluation of 5-(o-Tolyl)-1H-tetrazole Derivatives as Potent Anticonvulsant Agents

A series of 5-(o-tolyl)-1H-tetrazole derivatives were synthesized and evaluated for their anticonvulsant activities. 1-(2-Methylbenzyl)-5-(o-tolyl)-1H-tetrazole (3h) showed important anticonvulsant activity against the MES-induced seizures, as well as lower neurotoxicity with an ED₅₀ value of 12.7 mg/kg and a TD₅₀ value of over 500 mg/kg after intraperitoneal injection into mice, providing 3h with a high protective index (TD₅₀ /ED₅₀ ) of over 39.4. The achieved results prove that the distinctive compounds could be valuable as a model for future development, adaptation, and investigation to construct more active analogues.

Systematic review: antihypertensive drug therapy in patients of African and South Asian ethnicity

Despite the large differences in the epidemiology of hypertension across Europe, treatment strategies are similar for national populations of white European descent. However, hypertensive patients of African or South Asian ethnicity may require ethnic-specific approaches, as these population subgroups tend to have higher blood pressure at an earlier age that is more difficult to control, a higher occurrence of diabetes, and more target organ damage with earlier cardiovascular mortality. Therefore, we systematically reviewed the evidence on antihypertensive drug treatment in South Asian and African ethnicity patients. We used the Cochrane systematic review methodology to retrieve trials in electronic databases including CENTRAL, PubMed, and Embase from their inception through November 2015; and with handsearch. We retrieved 4596 reports that yielded 35 trials with 7 classes of antihypertensive drugs in 25,540 African ethnicity patients. Aside from the well-known blood pressure efficacy of calcium channel blockers and diuretics, with lesser effect of ACE inhibitors and beta-blockers, nebivolol was not more effective than placebo in reducing systolic blood pressure levels. Trials with morbidity and mortality outcomes indicated that lisinopril and losartan-based therapy were associated with a greater incidence of stroke and sudden death. Furthermore, 1581 reports yielded 16 randomized controlled trials with blood pressure outcomes in 1719 South Asian hypertensive patients. In contrast with the studies in African ethnicity patients, there were no significant differences in blood pressure lowering efficacy between drugs, and no trials available with mortality outcomes. In conclusion, in patients of African ethnicity, treatment initiated with ACE inhibitor or angiotensin II receptor blocker monotherapy was associated with adverse cardiovascular outcomes. We found no evidence of different efficacy of antihypertensive drugs in South Asians, but there is a need for trials with morbidity and mortality outcomes. Screening for cardiovascular risk at a younger age, treating hypertension at lower thresholds, and new delivery models to find, treat and follow hypertensives in the community may help reduce the excess cardiovascular mortality in these high-risk groups.

Angiotensin II status and sympathetic activation among hypertensive patients in Uganda: a cross-sectional study

Background

Sympathetic activation and renin-angiotensin system are essential for development and sustenance of hypertension. However, the status of these systems has not been well evaluated among patients in an African setting. This study therefore set out to assess the angiotensin II status and sympathetic activation among hypertensive patients in Uganda.

Methods

In this cross sectional study conducted at Mulago, the national referral hospital, blood samples were taken to measure angiotensin II, metanephrines and normetanephrines. Urine samples were also taken for measuring urine creatinine and sodium. The angiotensin II categories were defined using the Mosby’s Diagnostic and Laboratory Test References. 9th ed while the metanephrines and normetanephrine categories were defined using the Makerere University Biosafety II Immunology Laboratory reference values.

Results

162 patients were consented and enrolled into the study, of these 136 (84 %) had low, 15 (9 %) had normal, while, 11 (7 %) had high angiotensin II levels. 142 (88 %) participants had normal levels of metanephrine, while 20 (12 %) had high levels. Only 88 were assessed for metanephrines and of these 85 (97 %) had normal, while 3 (3 %) had raised levels. Urine sodium was associated with low and normal angiotensin II levels (P value 0.007). Female gender and diastolic blood pressure were associated with a protective effect against high normetanephrines (OR 0.29, P value 0.015), 80–89 mmHg (OR 0.19, p value 0.053), above 100 mmHg (OR 0.27, p value 0.022). Current smoking status was associated with high risk for abnormal normetanephrines (OR 17.6, P value −0.022) while former smoking was associated with high risk for abnormal metanephrines (OR 18.7, p value 0.022). After multivariate analysis, all the significant variables at bivariate analysis were still significant except those who stopped smoking and those with a BP at 80–89 which were not significant.

Conclusions

Hypertensive patients in this setting have predominantly low angiotensin II hypertension as a result of high salt intake. Sympathetic activation is not a significant mechanism of hypertension in this study population, more so in the females, with the exception of smokers who have a highly activated sympathetic system. Therefore, the use of agents targeting renin angiotensin and sympathetic systems as single first line antihypertensive agents in this setting should be re-evaluated if such patients are to be treated effectively.

Efficacy of fimasartan/hydrochlorothiazide combination in hypertensive patients inadequately controlled by fimasartan monotherapy

Background

The study reported here compared the blood pressure (BP)-lowering efficacy of fimasartan alone with that of fimasartan/hydrochlorothiazide (HCTZ) combination in patients whose BP goal was not achieved after 4 weeks of treatment with once-daily fimasartan 60 mg.

Methods

Patients with sitting diastolic blood pressure (siDBP) ≥90 mmHg with 4 weeks of once-daily fimasartan 60 mg were randomly assigned to receive either once-daily fimasartan 60 mg/HCTZ 12.5 mg or fimasartan 60 mg for 4 weeks. After 4 weeks, the dose was increased from fimasartan 60 mg/HCTZ 12.5 mg to fimasartan 120 mg/HCTZ 12.5 mg or from fimasartan 60 mg to fimasartan 120 mg if siDBP was ≥90 mmHg.

Results

Of the 263 randomized patients, 256 patients who had available efficacy data were analyzed. The fimasartan/HCTZ treatment group showed a greater reduction of siDBP compared to the fimasartan treatment group at Week 4 (6.88±8.10 mmHg vs 3.38±7.33, P=0.0008), and the effect persisted at Week 8 (8.67±9.39 mmHg vs 5.02±8.27 mmHg, P=0.0023). Reduction of sitting systolic BP in the fimasartan/HCTZ treatment group was also greater than that in the fimasartan treatment group (at Week 4, 10.50±13.76 mmHg vs 5.75±12.18 mmHg, P=0.0069 and, at Week 8, 13.45±15.15 mmHg vs 6.84±13.57 mmHg, P=0.0007). The proportion of patients who achieved a reduction of siDBP ≥10 mmHg from baseline and/or a mean siDBP <90 mmHg after 4 weeks of treatment was higher in the fimasartan/HCTZ treatment group than in the fimasartan treatment group (53.6% vs 39.8%, P=0.0359). The overall incidence of adverse drug reaction was 11.79% with no significant difference between the treatment groups.

Conclusion

The combination treatment of fimasartan and HCTZ achieved better BP control than fimasartan monotherapy, and had comparable safety and tolerance to fimasartan monotherapy.

Blood pressure-lowering efficacy of monotherapy with thiazide diuretics for primary hypertension

BACKGROUND

Hypertension is a modifiable cardiovascular risk factor. Although it is established that low-dose thiazides reduce mortality as well as cardiovascular morbidity, the dose-related effect of thiazides in decreasing blood pressure has not been subject to a rigorous systematic review. It is not known whether individual drugs within the thiazide diuretic class differ in their blood pressure-lowering effects and adverse effects.

OBJECTIVES

To determine the dose-related decrease in systolic and/or diastolic blood pressure due to thiazide diuretics compared with placebo control in the treatment of patients with primary hypertension. Secondary outcomes included the dose-related adverse events leading to patient withdrawal and adverse biochemical effects on serum potassium, uric acid, creatinine, glucose and lipids.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2014, Issue 1), Ovid MEDLINE (1946 to February 2014), Ovid EMBASE (1974 to February 2014) and ClinicalTrials.gov.

SELECTION CRITERIA

We included double-blind, randomized controlled trials (RCTs) comparing fixed-dose thiazide diuretic monotherapy with placebo for a duration of 3 to 12 weeks in the treatment of adult patients with primary hypertension.

DATA COLLECTION AND ANALYSIS

Two authors independently screened articles, assessed trial eligibility, extracted data and determined risk of bias. We combined data for continuous variables using a mean difference (MD) and for dichotomous outcomes we calculated the relative risk ratio (RR) with 95% confidence interval (CI).

MAIN RESULTS

We included 60 randomized, double-blind trials that evaluated the dose-related trough blood pressure-lowering efficacy of six different thiazide diuretics in 11,282 participants treated for a mean duration of eight weeks. The mean age of the participants was 55 years and baseline blood pressure was 158/99 mmHg. Adequate blood pressure-lowering efficacy data were available for hydrochlorothiazide, chlorthalidone and indapamide. We judged 54 (90%) included trials to have unclear or high risk of bias, which impacted on our confidence in the results for some of our outcomes.In 33 trials with a baseline blood pressure of 155/100 mmHg, hydrochlorothiazide lowered blood pressure based on dose, with doses of 6.25 mg, 12.5 mg, 25 mg and 50 mg/day lowering blood pressure compared to placebo by 4 mmHg (95% CI 2 to 6, moderate-quality evidence)/2 mmHg (95% CI 1 to 4, moderate-quality evidence), 6 mmHg (95% CI 5 to 7, high-quality evidence)/3 mmHg (95% CI 3 to 4, high-quality evidence), 8 mmHg (95% CI 7 to 9, high-quality evidence)/3 mmHg (95% CI 3 to 4, high-quality evidence) and 11 mmHg (95% CI 6 to 15, low-quality evidence)/5 mmHg (95% CI 3 to 7, low-quality evidence), respectively.Direct comparison of doses did not show evidence of dose dependence for blood pressure-lowering for any of the other thiazides for which RCT data were available: bendrofluazide, chlorthalidone, cyclopenthiazide, metolazone or indapamide.In seven trials with a baseline blood pressure of 163/88 mmHg, chlorthalidone at doses of 12.5 mg to 75 mg/day reduced average blood pressure compared to placebo by 12.0 mmHg (95% CI 10 to 14, low-quality evidence)/4 mmHg (95% CI 3 to 5, low-quality evidence).In 10 trials with a baseline blood pressure of 161/98 mmHg, indapamide at doses of 1.0 mg to 5.0 mg/day reduced blood pressure compared to placebo by 9 mmHg (95% CI 7 to 10, low-quality evidence)/4 (95% CI 3 to 5, low-quality evidence).We judged the maximal blood pressure-lowering effect of the different thiazides to be similar. Overall, thiazides reduced average blood pressure compared to placebo by 9 mmHg (95% CI 9 to 10, high-quality evidence)/4 mmHg (95% CI 3 to 4, high-quality evidence).Thiazides as a class have a greater effect on systolic than on diastolic blood pressure, therefore thiazides lower pulse pressure by 4 mmHg to 6 mmHg, an amount that is greater than the 3 mmHg seen with angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs) and renin inhibitors, and the 2 mmHg seen with non-selective beta-blockers. This is based on an informal indirect comparison of results observed in other Cochrane reviews on ACE inhibitors, ARBs and renin inhibitors compared with placebo, which used similar inclusion/exclusion criteria to the present review.Thiazides reduced potassium, increased uric acid and increased total cholesterol and triglycerides. These effects were dose-related and were least for hydrochlorothiazide. Chlorthalidone increased serum glucose but the evidence was unclear for other thiazides. There is a high risk of bias in the metabolic data. This review does not provide a good assessment of the adverse effects of these drugs because there was a high risk of bias in the reporting of withdrawals due to adverse effects.

AUTHORS' CONCLUSIONS

This systematic review shows that hydrochlorothiazide has a dose-related blood pressure-lowering effect. The mean blood pressure-lowering effect over the dose range 6.25 mg, 12.5 mg, 25 mg and 50 mg/day is 4/2 mmHg, 6/3 mmHg, 8/3 mmHg and 11/5 mmHg, respectively. For other thiazide drugs, the lowest doses studied lowered blood pressure maximally and higher doses did not lower it more. Due to the greater effect on systolic than on diastolic blood pressure, thiazides lower pulse pressure by 4 mmHg to 6 mmHg. This exceeds the mean 3 mmHg pulse pressure reduction achieved by ACE inhibitors, ARBs and renin inhibitors, and the 2 mmHg pulse pressure reduction with non-selective beta-blockers as shown in other Cochrane reviews, which compared these antihypertensive drug classes with placebo and used similar inclusion/exclusion criteria.Thiazides did not increase withdrawals due to adverse effects in these short-term trials but there is a high risk of bias for that outcome. Thiazides reduced potassium, increased uric acid and increased total cholesterol and triglycerides.

Antihypertensive prescribing patterns for adolescents with primary hypertension

BACKGROUND

Hypertension is an increasingly common problem in adolescents yet current medical management of primary hypertension in adolescents has not been well-described.

METHODS

We identified adolescents with primary hypertension by International Classification of Diseases, Ninth Revision codes and looked at prescription patterns chronologically for antihypertensive drug class prescribed and the specialty of prescribing physician. We also examined patient demographics and presence of obesity-related comorbidities.

RESULTS

During 2003-2008, there were 4296 adolescents with primary hypertension (HTN); 66% were boys; 73% were aged 11 to 14 years; 53% were black, 41% white, and 4% Hispanic; and 48% had obesity-related comorbidity. Twenty-three percent (977) received antihypertensive prescription. White subjects (odds ratio [OR]: 1.61; confidence interval [CI]: 1.39-1.88), older adolescents (≥15 years, OR: 2.11; CI: 1.79-2.48), and those with comorbidity (OR: 1.57; CI: 1.36-1.82) were more likely to receive antihypertensive prescriptions controlling for gender and years of Medicaid eligibility in logistic regression. Angiotensin converting enzyme inhibitors were the most frequently prescribed monotherapy. Nearly two-thirds of adolescents received prescriptions from adult primary care physicians (PCPs) only. More than one-quarter of adolescents who received a prescription received combination therapy, which was most often prescribed by adult PCPs.

CONCLUSIONS

Adult PCPs were the leading prescribers of antihypertensives for adolescents with primary HTN. Race differences exist in physicians' prescribing of antihypertensives to adolescents with primary HTN. The choice of antihypertensives by physicians of different specialties warrants additional study to understand the underlying rationale for treatment decisions and to determine treatment effectiveness.

An evaluation of the efficacy of olmesartan medoxomil in Black patients with hypertension

Blacks appear to have a more modest blood pressure (BP) response to angiotensin receptor blocker (ARB) monotherapy than non-Blacks. This post-hoc analysis compared the BP-lowering efficacy of olmesartan medoxomil (OM), losartan potassium (LOS), and valsartan (VAL) in Black versus non-Black participants in a randomized, forced-titration study. Patients were randomized to OM 20, LOS 50, and VAL 80mg/day or placebo for 4 weeks and uptitrated to 40, 100, and 320mg/day doses, respectively, by study end. The primary end point was the mean change from baseline in diastolic BP (DBP) at week 8. All treatments produced significant reductions in mean DBP and systolic BP (SBP) in Blacks (n=150; P < .001). BP <140/90mm Hg was achieved in 35.0%, 15.6%, 29.7%, and 5.0% of Blacks receiving OM, LOS, VAL, and placebo, respectively, and in 41.0%, 21.1%, 28.8%, and 14.5% of non-Blacks receiving OM, LOS, VAL, and placebo, respectively, after 8 weeks. BP-lowering efficacy of the three agents was similar at 3 months. OM had the greatest early efficacy, with numerically greater mean reductions in DBP and SBP, and a higher proportion of Black and non-Black patients achieving goal BP of 140/90mm Hg at week 8.

Clinical experience in treating hypertension with fixed-dose combination therapy: angiotensin II receptor blocker losartan plus hydrochlorothiazide

The goal of antihypertensive treatment is to reduce cardiovascular and cerebrovascular events associated with high blood pressure. A combination therapy with different antihypertensive agents is more successful than monotherapy in most hypertensive patients, with the added advantage of a better safety profile. Therefore, treatment of hypertensive patients with fixed-dose combination therapy consisting of the angiotensin II receptor blocker losartan along with hydrochlorothiazide (HCTZ) has several potential benefits over monotherapy with each individual component. It provides more effective blood pressure control, a reduction in the likelihood of adverse effects and facilitation of patient compliance due to a simple once-daily regimen. One of the advantages of the combination of losartan with HCTZ is the potential reduction in HCTZ-induced metabolic disorders; in particular, this combination can have attractive benefits for patients of hyperuricemia. Losartan plus HCTZ fixed-dose combination therapy is frequently recommended for the treatment of hypertension and lowers blood pressure in mild-to-moderate and even severe hypertensive patients to a level comparable with other classes of antihypertensive agents in combination with HCTZ. Fixed-dose combination therapy with losartan plus HCTZ is a logical choice as antihypertensive therapy for patients in whom combination therapy is necessary to achieve additional blood pressure reduction.

Inhibition of the renin-angiotensin-aldosterone system to prevent ischemic and atherothrombotic events

Blood pressure (BP) is a continuous risk factor for ischemic and atherosclerotic events such as stroke and ischemic heart disease, and controlling BP is a well-established component of any cardiovascular or cerebrovascular risk reduction regimen. In most patients, > or =2 medications with different mechanisms of action will be necessary to reach recommended BP goals. The neuroendocrine effects of the renin-angiotensin-aldosterone-system (RAAS) have proven to be excellent therapeutic targets for BP lowering. A number of antiatherosclerotic effects have been attributed to angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in addition to their antihypertensive effects. Because they have complementary actions on the RAAS, combination therapy with these agents has become the focus of recent clinical trials. This review describes the clinical data assessing the efficacy of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers individually and in combination in reducing the risk of stroke and ischemic heart disease.

Blood pressure responder rates versus goal rates: which metric matters?

Reducing blood pressure (BP) to guideline-recommended goals associated with reductions in cardiovascular risk is central to effective hypertension management. In addition to measuring BP reduction, clinical trials of antihypertensive agents should assess the percentage of patients responding to treatment. The Food and Drug Administration's defined rate of response required for drug approval is a reduction in diastolic BP (DBP) to <90 mmHg and/or a DBP reduction of > or = 10 mmHg. Consequently, some patients may be counted as responders even if they have not reached DBP <90 mmHg. An antihypertensive agent's effectiveness may be better assessed by the proportion of patients who achieve recommended BP goals. This article analyzes the frequency of response rates versus goal rates as endpoints in randomized trials since January 2001. Data showed that goal rates, especially combined systolic BP (SBP)/DBP goal rates, are consistently lower than response rates in studies evaluating both endpoints. Goal rates incorporating both SBP and DBP, or having a focus on SBP for individuals >50 years of age, provide the most clinically relevant information and are a more clinically relevant metric of an agent's ability to reduce BP than DBP alone.

Efficacy and safety of losartan 100 mg or losartan 100 mg plus hydrochlorothiazide 25 mg in the treatment of patients with essential arterial hypertension and CV risk factors: observational, prospective study in primary care

BACKGROUND

Patients with high cardiovascular risk are prevalent in ambulatory care. To achieve adequate blood pressure control, such patients require higher drug doses and/or combination therapy. We aimed to assess the efficacy and safety of losartan 100 mg as monotherapy or in fixed-dose combination with hydrochlorothiazide 25 mg.

DESIGN AND METHODS

Multicentre, prospective, open observational study over 13 weeks in patients with essential hypertension, whose blood pressure was not adequately controlled despite pretreatment. Main outcome parameters were the systolic (SBP) and diastolic (DBP) blood pressure reduction, the rate of normalized patients at study end compared to baseline, and the number and type of adverse events (AEs).

RESULTS

Of the 7702 documented patients, 53.1% (N = 4088) were men, with a mean age of 63.5 +/- 10.7 years. Comorbidities were frequent (diabetes mellitus in 57.4% [N = 4418], coronary heart disease in 30.3% [N = 2330], left ventricular hypertrophy in 28.2% [N = 2172], heart failure in 14.0% [N = 1079], and peripheral arterial disease in 9.0% [N = 690]). Patients received losartan 100 mg in 45.7% (N = 3521), losartan/HCTZ in 53.8% (N = 4143); additional antihypertensive drugs were given in 45.5% (N = 3505). Physicians reported somewhat lower target values than those stipulated by the guidelines (irrespective of age, gender, and concomitant diseases except for diabetes). Mean SBP/DBP decreased from a baseline value of 158/93 mmHg by 24/12 mmHg at study end. The BP lowering effect was similar in subgroups by treatment or comorbidity, respectively, however target attainment rates were substantially higher in non-diabetic patients. Metabolic and renal parameters (fasting glucose, HbA(1c), serum creatinine and albumin in urine) showed trends for improvement. Tolerability was very good, as only 0.43% (N = 33) experienced an AE (in 0.31% [N = 24] serious AEs), and 0.08% (N = 6) discontinued therapy due to reasons related to study drug.

CONCLUSION

In high-risk patients, treatment with losartan 100 mg or losartan/HCTZ 100/25 mg was effective and well tolerated, irrespective of comorbidity. These findings from a real-life setting are in line with those from randomized controlled trials.

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.

Prescribing patterns in hypertension: the emerging role of fixed-dose combinations for attaining BP goals in hypertensive patients

BACKGROUND

The attainment of clinical blood pressure (BP) goals can markedly reduce cardiovascular morbidity and mortality, yet approximately two-thirds of treated hypertensive patients in the United States have uncontrolled BP. Consequently, more aggressive management of hypertension, frequently involving combination therapy (e.g., fixed-dose combination [FDC] therapy), is needed to achieve the recommended BP goals of <140/90 mmHg for most patients, and <130/80 mmHg for high-risk patients.

SCOPE

This article, based on data from an extensive Medline search ('hypertension' AND 'prescribe', 'prescribing' OR 'prescription', date range: 1995-2007), focuses on prescribing patterns for antihypertensive medication, and on the emerging role of combination therapy, specifically FDC therapy, in treating hypertensive patients to target BP levels.

FINDINGS

Although the use of antihypertensive combination therapy has increased substantially in US adults over the last 20 years, such therapy remains considerably underutilized. Numerous studies have shown that combination therapies, including FDCs, can markedly reduce BP and adverse events relative to monotherapies, and this paper overviews data for various combination therapies: angiotensin-receptor blocker (ARB) + diuretic; angiotensin-converting enzyme (ACE) inhibitor + diuretic; calcium-channel blocker (CCB) + ACE inhibitor; and CCB + ARB. Specifically, fixed-dose CCB/ARB combinations of amlodipine with losartan, valsartan, or olmesartan medoxomil have recently been developed, and combination therapy schedules of amlodipine plus one of these ARBs have shown greater BP-lowering efficacy compared with the constituent monotherapies. Furthermore, in two large studies in a total of >3000 patients, CCB + ARB combination therapy was associated with significantly lower incidences of headache and peripheral edema than CCB monotherapy.

CONCLUSION

Guidelines for hypertension management clearly support the greater use of multidrug therapy, especially in high-risk patients. FDCs (e.g., various emerging CCB/ARB combinations) are a valuable option for such high-risk patients, as these combinations offer the potential to reduce adverse events, increase compliance, lower treatment costs, and improve BP goal-attainment rates.

Maximising antihypertensive effects of angiotensin II receptor blockers with thiazide diuretic combination therapy: focus on irbesartan/hydrochlorothiazide

BACKGROUND

Evidence-based guidelines for the management of hypertension are now well established. Studies have shown that more than 60% of patients with hypertension will require two or more drugs to achieve current treatment targets.

DISCUSSION

Combination therapy is recommended as first-line treatment by the JNC-7 guidelines for patients with a blood pressure > 20 mmHg above the systolic goal or 10 mmHg above the diastolic goal, while the International Society of Hypertension in Blacks recommends combination therapy when BP exceeds targets by > 15/10 mmHg. Current European Society of Hypertension-European Society of Cardiology guidelines also recommend the use of low-dose combination therapy in the first-line setting. Furthermore, JNC-7 recommends that a thiazide-type diuretic should be part of initial first-line combination therapy. Thiazide/diuretic combinations are available for a variety of classes of antihypertensive, including ACE inhibitors, angiotensin receptor blockers (ARBs), beta blockers and centrally acting agents. This article focuses on clinical data investigating the combination of an ARB, irbesartan, with the diuretic, hydrochlorothiazide.

CONCLUSIONS

These data indicate that the ARB/HCTZ combination has greater potency and a similar side effect profile to ARB monotherapy and represents a highly effective approach for attaining goal BP levels using a therapeutic strategy that very effectively lowers BP, is well tolerated and minimises diuretic-induced metabolic effects.

Antihypertensive efficacy and safety of fixed-dose combination therapy with losartan plus hydrochlorothiazide in Japanese patients with essential hypertension

A randomized, double-blind, placebo-controlled, parallel-group multicenter study was conducted to evaluate the antihypertensive efficacy and safety of 8-week treatment with one of three fixed-dose combinations-losartan 50 mg plus hydrochlorothiazide 12.5 mg, losartan 50 mg plus hydrochlorothiazide 6.25 mg, or losartan 25 mg plus hydrochlorothiazide 6.25 mg-in comparison with those of hydrochlorothiazide 12.5 mg alone, losartan 50 mg alone, or placebo in Japanese patients with essential hypertension. Significant reductions in sitting diastolic blood pressure (DBP) and systolic blood pressure (SBP) were seen in all three combination groups compared with the placebo group (each p<0.001). The greatest reductions in DBP and SBP were observed in the losartan 50 mg plus hydrochlorothiazide 12.5 mg group (12.7 and 18.0 mmHg, respectively). The reductions in the losartan 50 mg plus hydrochlorothiazide 12.5 mg group were significantly greater (each p<0.001) than those in the placebo group and each of the monotherapy groups. There were no significant differences in the incidences of clinical and laboratory drug-related adverse events between any of the combination groups and the placebo group. All combination groups showed improved hypokalemia and hyperuricemia compared to the hydrochlorothiazide 12.5 mg group. These results demonstrated that once-daily, fixed-dose combination therapy with losartan 50 mg plus hydrochlorothiazide 12.5 mg is well tolerated and more efficacious in lowering DBP and SBP than monotherapy in Japanese hypertensive patients.

The management of hypertension in African Americans

The prevalence of hypertension in blacks in the United States is among the highest in the world. Compared with whites, blacks develop hypertension at an earlier age, their average blood pressures are much higher and they experience worse disease severity. Consequently, blacks have a 1.3 times greater rate of nonfatal stroke, 1.8 times greater rate of fatal stroke, 1.5 times greater rate of heart disease death, 4.2 times greater rate of end-stage kidney disease, and a 50% higher frequency of heart failure; overall, mortality due to hypertension and its consequences is 4 to 5 times more likely in African Americans than in whites. The increased prevalence of hypertension and excessive target organ damage is due to a combination of genetic and, most likely, environmental factors. There are no clinical trial data at present to suggest that lower-than-usual BP targets should be set for high-risk demographic groups such as African Americans. The primary means of prevention and early treatment of hypertension in African Americans will be the appropriate use of lifestyle modification. The International Society of Hypertension in Blacks guidelines realize that most patients will require combination therapy, many of them first-line, to reach appropriate BP goals. Although certain classes and combinations of antihypertensive agents have been well-established to be effective, the choice of drugs for combination therapy in African American patients may be different. Within the African American group, the responsiveness to monotherapy with ACE inhibitors, angiotensin receptor blockers, and beta blockers may be less than the responsiveness to diuretics and calcium channel blockers, but these differences are corrected when diuretics are added to the neurohormonal antagonists. Of note, African American patients with systolic BP >15 mm Hg or a diastolic BP >10 mm Hg above goal should be treated with first-line combination therapy.

WITHDRAWN: Effect of antihypertensive drugs on mortality, morbidity and blood pressure in blacks

BACKGROUND

Black people have a greater prevalence of elevated blood pressure leading to excess morbidity and mortality.

OBJECTIVES

To systematically review the effects of different antihypertensive drugs on mortality, morbidity and blood pressure black adults with elevated blood pressure.

SEARCH STRATEGY

Medline, Embase, LILACS, African Index Medicus, the Cochrane Library November 2003; Pubmed September 2003 to March 2004. Searches were conducted without language restriction.

SELECTION CRITERIA

Randomised controlled trials of drugs versus placebo (blood pressure outcomes) or versus placebo or other drugs (morbidity and mortality outcomes).

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data unblinded. Disagreements were resolved by discussion. Authors were contacted twice to obtain missing information.

MAIN RESULTS

Full reports or abstracts from more than 2900 references of papers yielded 30 trials considering 53 interventions with 8 classes of antihypertensive drugs in 20,006 black patients from Africa, the Caribbean, and the United States of America, aged 18 to >80 years. In one large trial the main morbidity and mortality outcomes did not differ significantly between initial treatment drug classes when drugs were added to reach goal blood pressures. However, the comparison ACE Inhibitors vs diuretic favoured the diuretic for stroke 1.40 [1.17 to 1.68]; combined CHD 1.15 [1.02 to 1.30] and combined CVD 1.19 [1.09 to 1.30] and the comparison alpha blocker vs diuretic favoured the diuretic for combined CVD 1.40 [1.25 to 1.57]. In addition, all comparisons for heart failure favoured diuretic (1.47 [1.24 to 1.74] vs calcium blocker; 1.32 [1.11 to 1.58] vs ACE Inhibitor; and 2.18 [1.73 to 2.74] vs alpha blocker. The results also showed a greater occurrence of diabetes with diuretics. No significant differences were detected between placebo and beta adrenergic blockers in the reduction of systolic blood pressure (weighted mean difference [95% CI], -3.52 [-7.50 to 0.46] mm Hg). In addition, ACE inhibitors did not significantly differ from placebo in achievement of goal diastolic blood pressure (risk difference [95% CI], 5% [-10% to 21%]). Calcium blockers, diuretics, centrally acting agents, alpha adrenergic blockers and angiotensin II antagonists were all more effective than placebo in reducing blood pressure in the pooled analyses. Only calcium blockers remained effective in all prespecified subgroups, including baseline diastolic blood pressure >109 mm Hg.

AUTHORS' CONCLUSIONS

When first-line drugs from different classes are compared in the treatment of black people, there is no evidence of differential effects on most mortality and morbidity outcomes. Those morbidity differences that were found favoured diuretics. Drugs differ in their ability to reduce blood pressure in black people. Calcium blockers were the only drug class that reduced blood pressure in all subgroups of black people including those with severe hypertension. Beta-blockers, angiotensin receptor blocker, alpha blockers and ACE Inhibitors were least good at reducing blood pressure in black adults.

Dispelling the Myth of “Aggressive” Antihypertensive Therapy

Data from well designed randomized trials have proven the effectiveness of an intensive approach to hypertension management in reducing morbidity and mortality. Based on these data, guidelines recommend a blood pressure goal of <140/90 mm Hg in the general population, with lower goals for high-risk patients. Clinical trials also show that most patients will require at least two antihypertensive agents to reach goal. Despite this evidence base, only about one third of individuals with hypertension receive sufficient therapy to attain a blood pressure of <140/90 mm Hg. Physicians may be reluctant to use multiple antihypertensive agents to achieve this goal because they may consider it to be "aggressive" and not always in the best interests of the patient, especially in those deemed at low risk. Such perceptions may be founded on several myths: 1) the approach demands a complex, time-consuming titration-to-response strategy, during which the patient may be lost to follow-up; 2) it increases the pill burden, which will decrease patient compliance; 3) it increases treatment-related side effects; and 4) it is not cost-effective. The availability of fixed-dose combinations containing two antihypertensive agents should help to dispel these myths. Careful selection of efficacious, well tolerated, once-daily, fixed-dose combinations allows goal blood pressure to be achieved quickly in a broad range of patients and encourages patient concordance with therapy. Such formulations are also cost-effective. Thus, reducing blood pressure using multiple drugs as fixed-dose combinations is a strategy that recognizes the multiple pathophysiologic changes that lead to hypertension.

The influence of estimated creatinine clearance on plasma homocysteine in hypertensive patients with normal serum creatinine

OBJECTIVES

To examine the relation of estimated creatinine clearance (eCrCl) and plasma total homocysteine (tHcy) in hypertensive patients with a normal serum creatinine level.

DESIGN AND METHODS

A total of 137 hypertensive patients (mean age 66.6 years, 69 men) with serum creatinine level </=1.5 mg/dL gave 10-h fasting blood samples for measurement of tHcy, serum folic acid, and serum vitamin B(12).

RESULTS

95 patients fell into a chronic renal insufficiency (CRI) group (eCrCl< or =60 mL/min/1.73 m(2)) and 42 into a normal renal function (NRF) group (eCrCl>60 mL/min/1.73 m(2)). The CRI group was older (p<0.001), had higher tHcy (p<0.001), higher serum urea nitrogen (p<0.001), higher serum creatinine (p<0.001), lower eCrCl (p<0.001), and lower diastolic blood pressure (p=0.001). In univariate analysis, eCrCl had the strongest correlation with tHcy (r=-0.453, p<0.001). Significant correlations, ranging in decreasing order from r=-0.418, p<0.001 to r=-0.170, p=0.047, were also noted between tHcy and twelve other variables. In multivariate analysis, only eCrCl (p<0.001), usage of fibrate (p<0.001), serum level of vitamin B(12) (p=0.002), serum level of folic acid (p=0.009), and smoking (p=0.027) were independent predictors of tHcy.

CONCLUSION

eCrCl is a strong independent predictor of tHcy in hypertensive patients with normal serum creatinine.

Randomized, Double-Blind, Crossover Comparison of Amlodipine and Valsartan in African-Americans with Hypertension Using 24-Hour Ambulatory Blood Pressure Monitoring

STUDY OBJECTIVE

To compare the efficacy of amlodipine and valsartan in African-American patients with hypertension using ambulatory blood pressure monitoring (ABPM).

DESIGN

Prospective, randomized, double-blind, crossover comparison study.

SETTING

University-affiliated cardiac center clinic.

PATIENTS

Twenty African-Americans (12 men, 8 women), with a history of uncomplicated hypertension (blood pressure > 140/90 mm Hg).

INTERVENTION

Patients were randomized to receive amlodipine 5 or 10 mg/day or valsartan 80 or 160 mg/day for 8-10 weeks, depending on response. Dosages were titrated to achieve a blood pressure of 140/90 mm Hg or below. For patients whose blood pressures were not controlled, hydrochlorothiazide 12.5 mg/day was added to their regimens. Patients then underwent 24-hour ABPM. After an intervening washout period during which baseline blood pressure was reestablished, patients received the other treatment.

MEASUREMENTS AND MAIN RESULTS

Mean +/- SD baseline blood pressure before the two ABPM periods were 155 +/- 12/100 +/- 8 mm Hg and 156 +/- 11/101 +/- 9 mm Hg, respectively. Fifteen (75%) patients achieved goal blood pressure with amlodipine and 14 (70%) with valsartan (p=0.62). Final daily dosages were as follows: amlodipine 5 mg in nine patients, 10 mg in five patients, and 10 mg plus hydrochlorothiazide in six patients; valsartan 80 mg in nine patients, 160 mg in four patients, and 160 mg plus hydrochlorothiazide in seven patients. Ambulatory blood pressure monitoring was not completed in three patients due to adverse effects: headache and dizziness (one patient each, amlodipine and valsartan) and hyperkalemia (one patient, valsartan). Four patients (20%) in each treatment group had drug-related adverse effects. Results of ABPM including averages for 24-hour, daytime, nighttime, first 4 hours, and last 8 hours, and trough:peak ratios were not significantly different between the amlodipine- and valsartan-based treatments.

CONCLUSION

Based on both clinic blood pressure measurements and ABPM data, amlodipine and valsartan produced similar reductions in blood pressure in African-American patients with uncomplicated hypertension.

Renal risk and renoprotection among ethnic groups with type 2 diabetic nephropathy: a post hoc analysis of RENAAL

Type 2 diabetes is becoming the leading cause of end-stage renal disease (ESRD) worldwide. Prevalence of ESRD and the antihypertensive response to renin-angiotensin system intervention are suggested to vary among different ethnicities. The Reduction in Endpoints in Non-insulin dependent diabetes mellitus with the Angiotensin II Antagonist Losartan (RENAAL) study, which included different ethnic groups, demonstrated a renoprotective effect of losartan. A post hoc analysis from RENAAL was performed where we examined in each ethnic group the ESRD risk, identified independent predictors for ESRD, effect of degree of baseline albuminuria, effect of 6-month antiproteinuric response to therapy on ESRD, and renoprotective effect of losartan assessed by albuminuria reduction and ESRD. Baseline albuminuria was the strongest predictor for ESRD in every ethnic group. Albuminuria reduction was associated with reduced risk of ESRD while losartan reduced albuminuria in every ethnic group. When accounting for independent predictors of ESRD, losartan exhibited renoprotection in all ethnic groups. In this type 2 diabetic population with nephropathy, baseline albuminuria is the predominant risk parameter for ESRD; early antiproteinuric effect of losartan predicts long-term renoprotection; and losartan appears to be renoprotective in all ethnic groups. Since the RENAAL study was not powered to determine ethnic responses, these results underline the need for prospective trials where the aim is renal protection among different ethnic groups.

Angiotensin II antagonists: clinical experience in the treatment of hypertension, prevention of cardiovascular outcomes and renal protection in diabetic nephropathy and proteinuria

Angiotensin II antagonists (AIIAs) were introduced to treat hypertension about 10 years ago. During this period they were evaluated not only in terms of efficacy and safety but also in several large studies with clinical outcomes. They are efficacious in all clinical forms of hypertension and are effective also in all ethnic groups. Cardiovascular and renal protection in proteinuric diabetic nephropathy beyond blood pressure reduction was proved in major clinical studies: Losartan Intervention For Endpoint reduction in hypertension study (LIFE), Reduction of Endpoint in Non-Insulin dependent Diabetes Mellitus with the AII Antagonist Losartan (RENAAL) and Irbesartan Type 2 Diabetic Nephropathy Trial (IDNT). Their blood pressure independent protective effect is also mentioned by the blockade of AT1 receptor. As a class AIIs have a tolerability profile similar to placebo.

Angiotensin II antagonists--therapeutic benefits spanning the cardiovascular disease continuum from hypertension to heart failure and diabetic nephropathy

BACKGROUND

The cardiovascular benefits of angiotensin II antagonists (AIIAs) have been evaluated not only in terms of their ability to lower blood pressure but also on their ability to prevent strokes, cardiac events, and target organ damage. This review summarizes the body of evidence-based data demonstrating the efficacy of AIIAs across the spectrum of cardiovascular disease.

METHODS

A PubMed/MEDLINE search of English-language articles (1990 to September 2005) was used to identify articles describing clinical studies, particularly outcome trials, or mechanisms of therapeutic action pertinent to the therapy of cardiovascular disease or nephropathy.

FINDINGS

The antihypertensive efficacy of AIIAs is apparent across a wide spectrum of hypertensive patients, including black and Asian patients and patients with isolated systolic hypertension. More importantly, large outcome-based studies have demonstrated the efficacy of AIIAs across the continuum of cardiovascular disease, including hypertension, heart failure, post-myocardial infarction, and diabetic nephropathy. The Losartan Intervention For Endpoint reduction in hypertension study (LIFE), Reduction of Endpoints in Non-insulin-dependent Diabetes Mellitus with the AII Antagonist Losartan (RENAAL), and the Irbesartan Type 2 Diabetic Nephropathy Trial (IDNT) indicate that AIIAs confer cardiovascular and renal protective effects beyond their ability to lower blood pressure. These bloodpressure independent protective benefits of AIIAs may arise not only by blocking the deleterious effects of AII mediated via the AT1-receptor but may also be due to beneficial molecule-specific effects. As a class, AIIAs are well tolerated with an overall adverse event profile generally comparable to placebo and superior to that typically seen with calcium channel blockers, ACE inhibitors, diuretics, and beta-blockers.

CONCLUSIONS

By utilizing the body of clinical trial evidence as a guide to rational prescribing of AIIAs, practitioners can expect to deliver clinical benefits to their patients in terms of survival, prognosis, and quality of life.

Global differences in blood pressure control and clinical outcomes in the INternational VErapamil SR-Trandolapril STudy (INVEST)

BACKGROUND

The INternational VErapamil SR-Trandolapril Study (INVEST), a prospective, randomized, antihypertensive trial, found that two different medication regimens produced similar blood pressure (BP) control with equivalent cardiovascular (CV) outcomes (death from any cause, nonfatal myocardial infarction [MI], or nonfatal stroke).

HYPOTHESIS

The study was undertaken to investigate whether differences exist by global regions in demographics, treatment, and outcomes in the INVEST trial.

METHODS

Data were analyzed for 22,576 patients with stable coronary artery disease (CAD) enrolled in INVEST. We investigated differences in patient characteristics, treatment approaches, BP control, and clinical outcomes by creating three global regions based on geographical location: Northern Americas (NA), Caribbean (CA), and Eurasia (EA).

RESULTS

We observed significant regional differences in patient characteristics, treatment patterns, BP control, and CV outcomes. At baseline, patients from NA were older and had greater body mass index, higher rates of diabetes, peripheral vascular disease, and coronary revascularization, but lower rates of MI or left ventricular hypertrophy than patients in CA and EA. At 24 months, there were regional differences in both study and nonstudy antihypertensive drug use. Despite having higher mean baseline BP, patients from CA and EA achieved lower mean systolic BP throughout study follow-up. Furthermore, patients from both CA and EA had lower rates of all-cause mortality, fatal or nonfatal MI, fatal or nonfatal stroke, and newly diagnosed diabetes than patients from NA.

CONCLUSIONS

In INVEST, regional differences in medication utilization, BP control, and CV outcomes were identified. These disparities warrant further investigation to define appropriate care for patients with hypertension and stable CAD from an international public health perspective.

Clinical Pharmacology of Antihypertensive Therapy

Adequate control of blood pressure poses challenges for hypertensive patients and their physicians. Success rates of greater than 80% in reducing blood pressure to target values among high-risk hypertensive patients reported by several recent clinical trials argue that effective medications currently are available. Yet, only 34% of hypertensive patients in the United States are at their goal blood pressure according to the most recent national survey. Rational selection of antihypertensive drugs that target both the patient's blood pressure and comorbid conditions coupled with more frequent use of low-dose drug combinations that have additive efficacy and low adverse-effect profiles could improve significantly US blood pressure control rates and have a positive impact on hypertension-related cardiovascular and renal mortality and morbidity. This article reviews the pharmacokinetic and pharmacodynamic principles that underlie the actions of drugs in each of the classes of antihypertensive agents when used alone and in combination, provides practical pharmacologic information about the drugs most frequently prescribed for treatment of hypertension in the outpatient setting, and summarizes the current data influencing the selection of drugs that might be used most effectively in combination for the majority of hypertensive patients whose blood pressures are not controlled adequately by single-drug therapy.

Thiazide diuretics enhance nocturnal blood pressure fall and reduce proteinuria in immunoglobulin A nephropathy treated with angiotensin II modulators

OBJECTIVE

We examined whether thiazide diuretics could restore nocturnal blood pressure (BP) decline and reduce urinary protein excretion in patients with glomerulopathy treated with angiotensin II modulators (angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers).

METHODS

Twenty-five Japanese outpatients (11 men, 14 women; mean age 43 +/- 12 years) with biopsy-proven immunoglobulin (Ig)A nephropathy, preserved renal function (serum creatinine concentration </=1.2 mg/dl), stable non-nephrotic proteinuria (0.5-3 g daily), and treatment with angiotensin II modulators were studied. The patients received a diuretic, trichlormethiazide (2 mg daily) for 4 weeks after a baseline period lasting for 4 weeks.

RESULTS

Diuretic therapy significantly reduced conventional, 24-h, daytime and night-time blood pressures. Nocturnal blood pressure fall was significantly enhanced by diuretic therapy and a significant interaction existed between diuretic therapy and nocturnal fall in mean arterial pressure, which indicated that the degree of nocturnal blood pressure fall was affected by diuretic therapy. The urinary protein excretion rate was significantly reduced from 1.10 +/- 0.62 to 0.63 +/- 0.39 g/day by diuretic therapy. Diuretic/baseline ratio of urinary protein excretion rate was not correlated with diuretic/baseline ratio of conventional, 24-h and daytime mean arterial pressures, but with diuretic/baseline ratio of night-time mean arterial pressure (r = 0.54, P = 0.006).

CONCLUSIONS

Diuretics enhanced nocturnal BP decline and reduced urinary protein excretion in patients with IgA nephropathy treated with angiotensin II modulators. The combination of angiotensin II modulators and diuretics may have additional therapeutic advantages in relieving the renal and cardiovascular risks by reducing nocturnal high blood pressure.

Combination therapy in the management of hypertension: focus on angiotensin receptor blockers combined with diuretics

There is increasing evidence that combination therapy should be emphasized more than it is at present for the initial treatment of hypertensive patients. Recent guidelines acknowledge the value of combination therapy, although some treatment algorithms fail to echo this message. Observations from major clinical trials in the elderly, diabetics, stroke patients, and African Americans all indicate that combination therapy is necessary to control blood pressure in the majority of these patients. Several combination therapies such as an angiotensin II receptor blocker and a diuretic, an angiotensin-converting enzyme inhibitor with a diuretic, a beta blocker with a diuretic, or an angiotensin-converting enzyme inhibitor with a calcium antagonist have been shown to be effective in patients who do not respond to monotherapy. The current review focuses on the newest such combination; an angiotensin II receptor blocker and a diuretic may have an added advantage of being well tolerated. Recent studies have shown that angiotensin II receptor blockers, given alone or combined with a diuretic, may prevent some cardiovascular outcomes independent of their blood pressure-lowering efficacy.

Antihypertensive efficacy of angiotensin receptor blockers in combination with hydrochlorothiazide: a review of the factorial-design studies

Most hypertensive patients require more than one drug for adequate blood pressure (BP) control. The seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure recommends starting treatment with a thiazide diuretic or, when BP is >20/10 mm Hg above goal or in patients with diabetes, using two different antihypertensive agents. Searches of Medline, EMBASE, and BIOSIS databases identified four similarly designed, randomized, factorial studies comparing various doses of angiotensin II receptor blockers with hydrochlorothiazide as monotherapy and in combination. The methodology and results of these studies were compared. The primary efficacy end point in these studies was a decrease from baseline in mean diastolic BP after 8 weeks of therapy. All currently available angiotensin I receptor blocker/hydrochlorothiazide combinations evaluated (irbesartan, olmesartan medoxomil, telmisartan, and valsartan plus hydrochlorothiazide) produced significant systolic BP and diastolic BP reductions. Olmesartan medoxomil/hydrochlorothiazide 40 mg/25 mg provided the largest mean reduction in absolute and placebo-corrected systolic BP/diastolic BP. For all angiotensin II receptor blocker/hydrochlorothiazide combinations evaluated, > or =63% of patients achieved a diastolic BP response (diastolic BP <90 mm Hg or > or =10-mm Hg reduction). In conclusion, the combination of an angiotensin II receptor blocker and hydrochlorothiazide produces more substantial BP responses than monotherapy with either component.

Losartan

Losartan (Cozaar) is an angiotensin AT1 receptor antagonist. It is approved in numerous countries for the treatment of hypertension and has been approved in the UK, the US and several European countries for stroke risk reduction in patients with hypertension and left ventricular hypertrophy (LVH). Losartan is recommended for use alone or with hydrochlorothiazide, but it can also be administered with other antihypertensive medications. In patients with hypertension, losartan effectively lowers blood pressure and also leads to regression of LVH. In the large, well designed LIFE (Losartan Intervention For Endpoint reduction in hypertension) study in patients with hypertension and LVH, losartan was more effective than atenolol in reducing the composite primary endpoint of cardiovascular (CV) mortality, stroke or myocardial infarction (MI). This was mainly due to a significant 25% reduction in the risk of stroke in the losartan group. Losartan recipients also had a significantly lower incidence of new-onset diabetes mellitus compared with atenolol recipients. Similar benefits were observed in several patient subgroups from the LIFE study, but not in the subgroup of Black patients. Losartan is well tolerated and is a cost effective alternative to atenolol in the setting of stroke reduction. Comparative data on clinical outcomes in hypertensive patients for losartan versus other antihypertensive agents would be of interest. Nonetheless, in addition to its established antihypertensive and end organ effects, the LIFE study indicates that, with the possible exception of Black patients, losartan can reduce the risk of stroke in patients with hypertension and LVH.

Clinical guidelines for the treatment of hypertension in African Americans

African Americans represent a population with the highest prevalence of hypertension in the world, associated with earlier onset, more severity, poorer control rates, and more cardiovascular and renal complications than White Americans. The high prevalence of type 2 diabetes mellitus in African Americans, compared with Whites, compounds the excessive burden of cardiovascular and kidney disease. The Hypertension in African American Working Group of the International Society of Hypertension in Blacks recently developed a consensus document that presented a practical, evidence-based approach aimed at achieving better blood pressure control. It was thought that a new approach, targeted at US Blacks, was needed to achieve better blood pressure control and enhanced target tissue protection. Key elements of the document include (i) emphasis on the importance of therapeutic lifestyle modification such as weight loss, decreased sodium ingestion, increased potassium intake, exercise, and weight loss, to name a few; (ii) recommendation of combination antihypertensive agents because of the high prevalence of individuals with >15 mm Hg above SBP goal and/or 10 mmHg above DBP goal (140/90 unless there is also diabetes and/or kidney disease with >1 g proteinuria daily). Effective combinations include beta-adrenoceptor antagonist/diuretic, ACE inhibitor/diuretic, ACE inhibitor/calcium channel antagonist, and angiotensin receptor antagonist/diuretic; and (iii) the recommendations do not differ from other racial/ethnic groups where specific or compelling indications for the use of specific classes of antihypertensive agents exist.

Determinants of blood pressure response to quinapril in black and white hypertensive patients: the Quinapril Titration Interval Management Evaluation trial

Race has been considered an important factor in determining blood pressure response to treatment and selection of antihypertensive drug therapy. Data collected during a clinical trial that evaluated rapidity of medication up-titration with blood pressure response to monotherapy with the angiotensin-converting enzyme (ACE) inhibitor quinapril were used to characterize response in 533 black and 2046 white participants. Our objectives were to examine the influence of race and other factors on blood pressure response and to assess the degree to which nonrace factors account for apparent racial differences in response. Average systolic and diastolic blood pressure responses (baseline minus follow-up) to treatment were assessed with treatment groups combined. Crude systolic and diastolic blood pressure responses averaged 4.7 and 2.4 mm Hg less, respectively, in black compared with white participants; however, the response distributions largely overlapped. In multivariate linear regression models adjusted for study design variables and measured participant characteristics, the racial difference in systolic response was reduced by 51% to 2.3 mm Hg, and diastolic response by 21% to 1.9 mm Hg. In these models, participant characteristics, including age, gender, body size, and pretreatment blood pressure severity, significantly predicted either attenuated or enhanced blood pressure response to treatment. Our findings demonstrate that a large source of variability of blood pressure response to treatment is within, not between, racial groups, and that factors that vary at the level of the individual contribute to apparent racial differences in response to treatment.

Fixed combination therapy of hypertension: focus on valsartan/hydrochlorothiazide combination (Diovan/HCT)

Hypertension is a major risk factor for cardiovascular morbidity and mortality. Monotherapy of hypertension is often ineffective, since it controls approximately 50% of the blood pressure of hypertensive patients. For lowering blood pressure to less than 140/90 mmHg (or <130/80 mmHg among people with diabetes or chronic renal disease) according to JNC-7 guidelines, combination therapy of two or more drugs is often necessary. The combination of a diuretic with an angiotensin-converting enzyme inhibitor (ACEI) or an angiotensin receptor blocker (ARB) is effective and provides the additional benefit of blocking the effects of angiotensin II, which is responsible for cardiovascular remodeling and its complications. ARBs may have an advantage over the ACEIs because they block the action of all angiotensin II directly, whereas ACEIs are ineffective in blocking angiotensin II generated by nonclassical ACE pathways. Valsartan (Diovan, Novartis) is one of the seven currently approved ARBs in the USA for the treatment of hypertension, and it has been shown to be very effective in controlling blood pressure given once-daily in doses of 80-160 or 320 mg. Its fixed combination with hydrochlorothiazide (HCT) is even more effective in controlling blood pressure in 70% of the cases. The most commonly used combinations are valsartan/HCT (Diovan/HCT), 80/12.5 and 160/12.5 mg given once-daily.

Optimal treatment of hypertension in African Americans. Reaching and maintaining target blood pressure goals

Treatment of hypertension in African Americans has special challenges, including a lack of objective trial data on which to base decisions and differing benefits and responses than with other patients. However, adequate control is possible and should be the goal of treating physicians. This article describes current "best practice" guidance on appropriate treatment of high blood pressure in African Americans. Two patient scenarios offer insight into clinical strategies.

Evolving strategies for the use of combination therapy in hypertension

Two thirds of patients with hypertension require more than one drug to achieve goal blood pressure. Rational antihypertensive drug combinations are based on their ability to produce additive blood pressure reduction and reduce the incidence of dose-dependent side effects. Some combinations exhibit side-effect neutralization in which side effects associated with one drug are neutralized by a second agent. Fixed-dose combinations improve adherence by reducing the number of pills and simplifying the treatment regimen. Because volume overload is common, low-dose diuretics are often included in drug combinations. Combinations of diuretics with potassium-sparing diuretics, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, and b-blockers are useful in treating large segments of the hypertensive population. Combinations of calcium channel blockers and angiotensin converting enzyme inhibitors are also effective and reduce the incidence of calcium blocker-related edema. Combinations of agents affecting the renin-angiotensin system by different mechanisms are currently the subject of active investigation.

A multicenter, randomized, double-blind, placebo-controlled, 8-week trial of the efficacy and tolerability of once-daily losartan 100 mg/hydrochlorothiazide 25 mg and losartan 50 mg/hydrochlorothiazide 12.5 mg in the treatment of moderate-to-severe essential hypertension

BACKGROUND

Many patients with moderate-to-severe hypertension require multiple drug therapy to achieve blood-pressure goals. Fixed-dose combination therapy with losartan and hydrochlorothiazide may be useful in this population.

OBJECTIVE

This study was conducted to obtain additional data on the antihypertensive efficacy and tolerability of once-daily, fixed-dose combinations of losartan and hydrochlorothiazide.

METHODS

This was a multicenter, randomized, double-blind, parallel-group, placebo-controlled trial. Patients > or = 21 years of age with moderate-to-severe essential hypertension, defined as a mean trough sitting diastolic blood pressure (SiDBP) of 105 to 115 mm Hg, were randomly assigned in a 2:2:1 ratio to receive losartan 100 mg/hydrochlorothiazide 25 mg (L100/25), losartan 50 mg/hydrochlorothiazide 12.5 mg (L50/12.5), or placebo (PBO) once daily for 8 weeks. The primary efficacy measurement was the mean change from baseline in trough SiDBP in the L100/25 versus L50/12.5 treatment groups. Responders were defined as patients with mean trough SiDBP <90 mm Hg or a > or = 10-mm Hg decrease in mean trough SiDBP.

RESULTS

A total of 446 patients were randomly assigned to receive L100/25 (n = 173), L50/12.5 (n = 184), or PBO (n = 89). At week 8, mean trough SiDBP was significantly lower than at baseline in the L100/25 (-17.5 mm Hg), L50/12.5 (-15.2 mm Hg), and PBO groups (-8.5 mm Hg) (all P < 0.001). The difference between the active-treatment groups was statistically significant (-2.2 mm Hg; 95% Cl, range -3.8 to -0.6) (P = 0.006), as was the difference between the L100/25 and PBO groups (-9.0 mm Hg; 95% CI, range -I1.0 to -7.0) (P < 0.001) and the L50/12.5 and PBO groups (-6.7 mm Hg; 95% CI, range -8.7 to -4.8) (P < 0.001). At week 8, the percentages of responders were 86.7% (144 of 166), 78.9% (142 of 180), and 50.0% (42 of 84) in the L100/25, L50/12.5, and PBO groups, respectively. The incidence of adverse experiences (AEs) was 34.7% (60 of 173) in the L100/25 group, 23.9% (44 of 184) in the L50/12.5 group, and 32.6% (29 of 89) in the PBO group. The incidence of drug-related AEs was similar among the treatment groups (L100/25, 7.5% [13 of 173]; L50/12.5, 7.1% [13 of 184]; and PBO, 11.2% [10 of 89]).

CONCLUSIONS

This study demonstrates the antihypertensive efficacy and tolerability of the once-daily, fixed-dose combination L50/12.5 in patients with moderate-to-severe essential hypertension. In this study, L100/25 provided additional anti-hypertensive efficacy beyond that of L50/12.5 (and both were more efficacious than PBO). Approximately 4 of 5 patients (78.9%) treated with L50/12.5 responded to therapy, as did nearly 9 of 10 patients (86.7%) treated with L100/25. The tolerability profiles of L50/12.5 and L100/25 were similar to that of PBO.

Rationale for fixed-dose combinations in the treatment of hypertension: the cycle repeats

Single-drug therapy remains the preferred way to begin treatment of hypertension, although in many patients this is unable to bring blood pressure (BP) to goal levels. Single-drug therapy, even when maximally titrated, is at best only modestly effective in normalising BP in Stage-I or II hypertension, which represents the majority of the hypertensive population. It is increasingly appreciated that the elusive goal of a 'normal' BP is achieved only if multi-drug therapy is employed. This is especially so when considered in the context of today's lower BP goals. The options for multi-drug therapy are quite simple: either fixed-dose combination therapy or drugs added sequentially one after another to then arrive at an effective multi-drug regimen. Advocates exist for both approaches. A considerable legacy, dating to the 1950's, exists for fixed-dose combination therapies. The rationale to this approach has remained constant. Fixed-dose combination therapy successfully reduces BP because two drugs, each typically working at a separate site, block different effector pathways. In addition, the second drug of such two-drug combinations may check counter-regulatory system activity triggered by the other. For example, a diuretic and beta-blocker combination may find the diuretic correcting the salt-and-water retention which occasionally accompanies beta-blocker therapy. The pattern of adverse effects also differs with fixed-dose combination therapy, in part, because less drug is generally being given. In addition, one component of a fixed-dose combination therapy can effectively counterbalance the tendency of the other to produce adverse effects. For example, the peripheral oedema, that accompanies calcium channel antagonist therapy, occurs less frequently when an ACE inhibitor is co-administered. ACE inhibitors improve, if not eliminate, the peripheral oedema associated with calcium channel antagonists because of their proven ability to cause venodilation. In addition, diuretic therapy-induced volume contraction may generate a state of secondary hyperaldosteronism and thereby electrolyte abnormalities such as hypokalaemia and/or hypomagnesaemia. In many cases, the co-administration of either an ACE inhibitor or an angiotensin II receptor blocker with a diuretic corrects the aforementioned electrolyte disturbances. Fixed-dose combination therapy has a proven record of reducing BP. This form of treatment has been available for close to a half-century. Over that period of time, many physicians have taken advantage of this therapeutic approach even when academic opinion was less than charitable to this concept. Academic opinion is rarely immutable and occasionally irrelevant to prescription practice. Prescription practice is driven by many considerations including ease of use, cost and tolerance of a therapy. Most importantly, the therapeutic pathway taken should successfully result in goal BP being reached in a large number of those treated. Unfortunately, despite the simplicity of the concept behind fixed-dose combination therapy, its success will ultimately rest on cost. If made truly cost-competitive, it will gain an increasing share of the hypertensive market. If not, market forces will relegate it to a secondary role for hypertension treatment.