Double-blind comparison of losartan, lisinopril, and metolazone in elderly hypertensive patients with previous angiotensin-converting enzyme inhibitor-induced cough

Angiotensin-converting enzyme inhibitor induced cough compared with placebo, and other antihypertensives: A systematic review, and network meta-analysis

Studies have shown that angiotensin converting enzyme inhibitors (ACEIs) are superior in primary and secondary prevention for cardiac mortality and morbidity to angiotensin receptor blocker (ARBs). One of the common side effects from ACEI is dry cough. The aims of this systematic review, and network meta-analysis are to rank the risk of cough induced by different ACEIs and between ACEI and placebo, ARB or calcium channel blockers (CCB). We performed a systematic review, and network meta-analysis of randomized controlled trials to rank the risk of cough induced by each ACEI and between ACEI and placebo, ARB or CCB. A total of 135 RCTs with 45,420 patients treated with eleven ACEIs were included in the analyses. The pooled estimated relative risk (RR) between ACEI and placebo was 2.21 (95% CI: 2.05-2.39). ACEI had more incidences of cough than ARB (RR 3.2; 95% CI: 2.91, 3.51), and pooled estimated of RR between ACEI and CCB was 5.30 (95% CI: 4.32-6.50) Moexipril ranked as number one for inducing cough (SUCRA 80.4%) and spirapril ranked the least (SUCRA 12.3%). The order for the rest of the ACEIs are as follows: ramipril (SUCRA 76.4%), fosinopril (SUCRA 72.5%), lisinopril (SUCRA 64.7%), benazepril (SUCRA 58.6%), quinapril (SUCRA 56.5%), perindopril (SUCRA 54.1%), enalapril (SUCRA 49.7%), trandolapril (SUCRA 44.6%) and, captopril (SUCRA 13.7%). All ACEI has the similar risk of developing a cough. ACEI should be avoided in patients who have risk of developing cough, and an ARB or CCB is an alternative based on the patient's comorbidity.

Rare case of losartan-induced cough complicated by rectus sheath haematoma: in a patient on rivaroxaban therapy

Spontaneous rectus sheath haematomas and cough secondary to losartan are individually rare conditions. Abdominal wall haematomas present with abdominal pain and abdominal mass. Most patients are managed conservatively; Surgery or embolisation is indicated for shock, infection, rupture into the peritoneum or intractable pain. This is a man aged 65 years presented with dry cough and right-sided abdominal pain. He started losartan a few weeks prior to the onset of cough and had been on rivaroxaban for prior deep venous thrombosis. The right side of his abdomen was distended, bruised and tender. His haemoglobin dropped from 13.3to 9.5 g/dL. CT abdomen/pelvis showed a large 14.5×9.1×4.5 cm haematoma within the right lateral rectus muscle. His only risk factor for developing rectus sheath haematoma was cough in the setting of anticoagulation. Dry cough due to angiotensin receptor blockers is rare, but can have very serious consequences.

Tolerability of angiotensin-receptor blockers in patients with intolerance to angiotensin-converting enzyme inhibitors: a systematic review and meta-analysis

BACKGROUND

Between 5% and 20% of patients treated with angiotensin-converting enzyme inhibitors (ACE inhibitors) develop intolerance. Angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) can be used as an alternative treatment.

OBJECTIVE

In this study we aimed to evaluate the tolerability of ARBs in patients with intolerance to ACE inhibitors.

DATA SOURCES

The electronic databases PubMed, MEDLINE/EMBASE via Dialog, CENTRAL, and ISI Web of Knowledge were searched.

STUDY SELECTION

Randomized controlled trials (RCTs) evaluating ARBs in patients with intolerance to ACE inhibitors were selected.

DATA SYNTHESIS

Risk ratio (RR) and 95% confidence intervals (CIs) were estimated assuming the random effects method. We found 11 RCTs comparing ARBs with ACE inhibitors, diuretics, or placebo, and one RCT comparing high-dose versus low-dose ARB.

RESULTS

ARBs had fewer cough events versus ACE inhibitors (RR 0.37; 95% CI 0.28, 0.48). ARBs had drug discontinuation (RR 0.99; 95% CI 0.84, 1.17) and cough risk (RR 1.01; 95% CI 0.74, 1.39) rates similar to placebo. Angioedema risk with ARBs was also similar to placebo (RR 1.62; 95% CI 0.17, 15.79). Compared with placebo, hypotension (RR 2.63; 95% CI 1.77, 3.92), renal dysfunction (RR 2.07; 95% CI 1.45, 2.95) and hyperkalemia (RR 3.37; 95% CI 1.60, 7.11) were more frequent with ARBs.

CONCLUSIONS

ACE inhibitor rechallenge should be discouraged in patients with previous intolerance to ACE inhibitors due to a higher risk of cough. ARBs had cough and angioedema incidences similar to placebo. Despite a significantly higher incidence of hypotension, renal dysfunction and hyperkalemia, discontinuation of ARBs was similar to placebo.

A regulator’s view of comparative effectiveness research

Background ‘Comparative effectiveness’ is the current enthusiasm, and for good reason. After knowing a treatment works, the most critical question is how it compares with alternatives. Comparative studies are not commonly conducted by drug companies and they represent a significant methodological challenge. Comparative data could include evidence of overall superiority to an alternative or advantages in identifiable subsets, for example, people who do not respond to or tolerate alternatives, or members of a genetic subset and could also include convincing evidence that there is little difference between two treatments.

Purpose To describe regulations, guidance, and Food and Drug Administration experience related to studies of comparative effectiveness, including approaches to showing superiority and problems encountered in showing similarity.

Methods Review of Food and Drug Administration regulations and guidance and experience with showing superiority and similarity, particularly related to randomized trials and epidemiologic studies.

Results Methods exist, and they have been successful for showing overall superiority of one drug over another, advantages in specific population subsets. Efforts to show true equivalence face problems of definition and very large sample sizes needed to rule out small differences.

Limitations There is need for further discussion of what is meant by similarity or equivalence of two treatments.

Conclusion Comparative studies are challenging because differences between effective therapies are likely to be small and can be detected reliably only in randomized trials, often large ones. Despite the difficulties, comparative trials have been successful and we clearly would like to see more of them.

Long-term use and tolerability of irbesartan for control of hypertension

In this review, we discuss the pharmacological and clinical properties of irbesartan, a noncompetitive angiotensin II receptor type 1 antagonist, successfully used for more than a decade in the treatment of essential hypertension. Irbesartan exerts its antihypertensive effect through an inhibitory effect on the pressure response to angiotensin II. Irbesartan 150-300 mg once daily confers a lasting effect over 24 hours, and its antihypertensive efficacy is further enhanced by the coadministration of hydrochlorothiazide. Additionally and partially beyond its blood pressure-lowering effect, irbesartan reduces left ventricular hypertrophy, favors right atrial remodeling in atrial fibrillation, and increases the likelihood of maintenance of sinus rhythm after cardioversion in atrial fibrillation. In addition, the renoprotective effects of irbesartan are well documented in the early and later stages of renal disease in type 2 diabetics. Furthermore, both the therapeutic effectiveness and the placebo-like side effect profile contribute to a high adherence rate to the drug. Currently, irbesartan in monotherapy or combination therapy with hydrochlorothiazide represent a rationale pharmacologic approach for arterial hypertension and early-stage and late-stage diabetic nephropathy in hypertensive type II diabetics.

Clinical effectiveness of telmisartan alone or in combination therapy for controlling blood pressure and vascular risk in the elderly

Elderly patients (age ≥ 65 years) with hypertension are at high risk for vascular complications, especially when diabetes is present. Antihypertensive drugs that inhibit the renin-angiotensin system have been shown to be effective for controlling blood pressure in adult and elderly patients. Importantly, renin-angiotensin system inhibitors were shown to have benefits beyond their classic cardioprotective and vasculoprotective effects, including reducing the risk of new-onset diabetes and associated cardiovascular effects. The discovery that the renin-angiotensin system inhibitor and angiotensin II type 1 (AT(1)) receptor blocker (ARB), telmisartan, can selectively activate the peroxisome proliferator-activated receptor-γ (PPARγ, an established antidiabetic drug target) provides the unique opportunity to prevent and treat cardiovascular complications in high-risk elderly patients with hypertension and new-onset diabetes. Two large clinical trials, ONTARGET (Ongoing Telmisartan Alone in combination with Ramipril Global Endpoint Trial) and TRANSCEND (Telmisartan Randomized AssessmeNt Study in ACE-I iNtolerant subjects with cardiovascular disease) have assessed the cardioprotective and antidiabetic effects of telmisartan. The collective data suggest that telmisartan is a promising drug for controlling hypertension and reducing vascular risk in high-risk elderly patients with new-onset diabetes.

Recurrent attacks of post-intubation right upper lobe atelectasis

A 22-year-old woman with no history of asthma developed an acute recurrent attack of severe bronchoconstriction and right upper lobe atelectasis immediately after laryngoscopy and endotracheal intubation. The first attack had taken place 2 months earlier under identical circumstances. Induction of anesthesia for tracheal intubation was achieved using propofol, fentanyl, and rocuronium. Bronchial obstruction and bronchial intubation were excluded by bronchoscopy. The atelectasis was quickly resolved with mechanical ventilation and spasmolytic treatment on both occasions. The surgical procedure could proceed soon after resolution of the atelectasis.

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

BACKGROUND AND OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Angiotensin II receptor blockers in congestive heart failure

The benefits of angiotensin-converting enzyme (ACE) inhibitors for the treatment of congestive heart failure (CHF) are well-established. A newer class of medications, angiotensin II receptor blockers (ARBs), may be a suitable replacement for ACE inhibitors as a result of a more complete inhibition of angiotensin II and better tolerability among patients. To examine the current literature on the efficacy and safety of ARBs in the setting of CHF, a Medline search was conducted of the English language literature for the years 1987 to 2005. Clinical trials that reported data on cardiac outcomes were reviewed. The earlier trials were direct ARB to ACE inhibitor comparisons (ELITE I and ELITE II). These studies indicated that ARBs do not confer an improvement in cardiac outcomes over ACE inhibitors. RESOLVD, Val-HeFT, and the 3 separate trials of the CHARM program investigated the addition of an ARB to standard therapy. The RESOLVD trial showed no significant differences in clinical events among ACE inhibitor, ARB, and their combination. Although no mortality benefit was evident in the Val-HeFT trial, a substantial reduction in CHF rehospitalizations was reported among patients who were not receiving ACE inhibitor therapy. The CHARM-Overall program demonstrated a significant benefit in cardiovascular death and hospital admissions for CHF with the addition of ARB to standard therapy, a benefit that was more pronounced in patients with depressed left ventricular ejection fraction. In the setting of CHF, rates of cardiac outcomes do not differ substantially between ARBs and ACE inhibitors. However, their combination may improve outcomes for patients with CHF.

The Role of Angiotensin II Type 1 Receptor Antagonists in Elderly Patients with Hypertension

Hypertension is a major risk factor for stroke and coronary events in elderly people and clinical trials have shown that treatment of hypertension with various drugs can result in a substantial reduction in cerebrovascular and cardiovascular events. The angiotensin II type 1 (AT1) receptor antagonists are the newest class of antihypertensive agents to be used widely in clinical practice. AT1 receptor antagonists can generally be given once-daily. They are also extremely well tolerated with minimal first-dose hypotension and an incidence of adverse effects similar to that seen with placebo. Adverse event rates are significantly lower than with other classes of antihypertensive drugs including ACE inhibitors. These factors result in improved compliance and increased rates of continuance on therapy. AT1 receptor antagonists show similar efficacy in lowering blood pressure to other classes of antihypertensive agents and their antihypertensive effect is potentiated when they are given concomitantly with low-dose thiazide diuretics. AT1 receptor antagonists are eliminated predominantly by the hepatic route but most are not subject to extensive metabolism and interactions with other drugs are uncommon. This is an advantage in the elderly, who are often receiving multiple medications which increases the risk for adverse drug interactions. Dose adjustments are not usually required in the elderly unless there is plasma volume depletion. Although plasma AT1 receptor antagonist concentrations are generally higher in the elderly than in younger subjects, this pharmacokinetic difference may be balanced by decreased activation of the circulating renin-angiotensin-aldosterone system in the elderly. Recent clinical studies in high-risk hypertensive patients with left ventricular hypertrophy or in patients with diabetic nephropathy or heart failure have demonstrated that AT1 receptor antagonists can improve clinical outcomes to a similar or sometimes greater extent than other antihypertensive agents. Many of these studies have included large numbers of older patients and have confirmed the excellent tolerability profile of these drugs. Thus, AT1 receptor antagonists should be considered as a possible first-line treatment or as a component of combination therapy in patients with type 2 diabetes mellitus and microalbuminuria or nephropathy and as an alternative or additional treatment to ACE inhibitors in patients with heart failure or left ventricular dysfunction. AT1 receptor antagonists also appear to reduce the onset of new diabetes compared with some other antihypertensive drugs. The benefits in terms of organ protection have mainly been seen in studies using higher doses of particular AT1 receptor antagonists and it is not certain at present whether these results can be extrapolated to other members of the class. As the elderly are more likely to have developed organ damage related to hypertension or to have heart failure or diabetes as concomitant conditions, AT1 receptor antagonists represent an appropriate option for many elderly patients. The main disadvantage of these drugs is the cost of the medication but this may be offset by their improved tolerability with fewer adverse reactions and thus increased compliance, resulting in better blood pressure control and fewer clinical events. Overall, AT1 receptor antagonists are well tolerated and efficacious for blood pressure-lowering when given as a single daily dose in elderly patients and have many potential benefits in high-risk hypertensive subjects.

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.

ACE2: A novel therapeutic target for cardiovascular diseases

Hypertension afflicts over 65 million Americans and poses an increased risk for cardiovascular morbidity such as stroke, myocardial infarction and end-stage renal disease resulting in significant mortality. Overactivity of the renin-angiotensin system (RAS) has been identified as an important determinant that is implicated in the etiology of these diseases and therefore represents a major target for therapy. In spite of the successes of drugs inhibiting various elements of the RAS, the incidence of hypertension and cardiovascular diseases remain steadily on the rise. This has lead many investigators to seek novel and innovative approaches, taking advantage of new pathways and technologies, for the control and possibly the cure of hypertension and related pathologies. The main objective of this review is to forward the concept that gene therapy and the genetic targeting of the RAS is the future avenue for the successful control and treatment of hypertension and cardiovascular diseases. We will present argument that genetic targeting of angiotensin-converting enzyme 2 (ACE2), a newly discovered member of the RAS, is ideally poised for this purpose. This will be accomplished by discussion of the following: (i) summary of our current understanding of the RAS with a focus on the systemic versus tissue counterparts as they relate to hypertension and other cardiovascular pathologies; (ii) the newly discovered ACE2 enzyme with its physiological and pathophysiological implications; (iii) summary of the current antihypertensive pharmacotherapy and its limitations; (iv) the discovery and design of ACE inhibitors; (v) the emerging concepts for ACE2 drug design; (vi) the current status of genetic targeting of the RAS; (vii) the potential of ACE2 as a therapeutic target for hypertension and cardiovascular disease treatment; and (viii) future perspectives for the treatment of cardiovascular diseases.

Factors influencing the switch in the use of antihypertensive medications

The present study was undertaken to explore factors associated with observance of prescribed antihypertensive medications. Secondary data analysis utilising ambulatory claims of the Taiwan National Health Insurance involved all initially treated hypertensive patients (n=565,048) from June 1, 1997 to June 30, 1998. The main outcome measure was the statistical analysis of factors prompting medication switch and dropout rates. The overall continuity rate was 51%. Specific continuity rates were 40% for calcium antagonists, 36% for angiotensin-converting enzyme inhibitors, 35% for beta-blockers and 29% for diuretics. Less than 30% of patients changed medications and more than 20% of patients changed clinics. The change increased the likelihood of switching medications sevenfold. Switch was minimal for calcium antagonists. Patients taking calcium antagonists were the least likely to switch medications and had the lowest dropout rate. Changing clinics was the most influential medication switch factor.

Treatment of systemic hypertension in patients with pulmonary disease: COPD and asthma

We present a two-part review of the English-language literature pertaining to drug therapy for systemic high BP in patients with pulmonary diseases. Part I examines the literature pertaining to the use of antihypertensive drugs in patients with systemic hypertension and coexisting pulmonary conditions, especially COPD and asthma. Part II of the series reviews studies assessing the relationship between sleep-disordered breathing (including the role of the sympathetic nervous system) and systemic hypertension, and presents an approach to the management of these patients. It is the aim of both parts of this review to make qualified conclusions and recommendations applying a methodologic critique to assess the current literature. In the first part of this series, we review the demographics of hypertension in patients with COPD. This is followed by an extensive review of the use of specific classes of antihypertensive drug therapies in patients with pulmonary disease. The antihypertensive agents reviewed include diuretics, calcium antagonists, angiotensin-converting enzyme inhibitors, and angiotensin II receptor antagonists, beta-adrenergic blocking agents, and alpha-beta-blockers and other non-beta-blocker classes. Additionally, the renin angiotensin system is briefly reviewed, with a discussion of how angiotensin-converting enzyme inhibitors induce cough, especially in pulmonary and congestive heart failure patients.

Role of valsartan and other angiotensin receptor blocking agents in the management of cardiovascular disease

Blockade of the renin-angiotensin system by angiotensin converting enzyme (ACE) inhibitors reduces mortality and morbidity in patients post-myocardial infarction as well as in chronic heart failure and hypertension. ACE inhibitors also have a well-established place in the treatment of diabetic nephropathy. Angiotensin receptor blockers (ARBs) have been developed to produce a more complete blockade of the actions of angiotensin II as compared to other drug classes, as well as an improved side effect profile. This article provides an overview of the place of ARBs in general and of the ARB valsartan in particular, and draws comparisons to ACE inhibitors in the treatment of cardiovascular diseases.

Angiotensin II receptor blockers in the treatment of heart failure

Heart failure treatment centers on antagonism of the renin-angiotensin-aldosterone system and adrenergic nervous system. Angiotensin-converting enzyme (ACE) inhibitors have been shown to benefit patients with left ventricular systolic dysfunction irrespective of symptoms. Despite ACE inhibitor use, left ventricular dysfunction continues to progress in most patients. In addition, ACE inhibitors are substantially underused in patients who would benefit, in large part due to physician concern over potential adverse effects. Angiotensin receptor blockers (ARBs) have been proposed as either potential substitutes for ACE inhibitors or as additive therapy for heart failure patients. The authors will review the importance of the renin-angiotensin-aldosterone system in the progression of heart failure, as well as the mechanisms by which ACE inhibitors and ARBs counteract this effect. The clinical evidence to date supporting the use of ARBs in heart failure also will be reviewed. Based on current trials, ARBs are suitable substitutes for ACE inhibitors in patients who have true ACE inhibitor intolerance, but ACE inhibitors should still be considered first-line therapy in the treatment of left ventricular systolic dysfunction and heart failure. ARBs are a reasonable additive therapy in patients on maximal ACE inhibitor therapy who remain symptomatic, especially in patients unable to tolerate beta blockade.

ACE inhibitor-induced bronchial reactivity in patients with respiratory dysfunction

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors are often associated with an increased incidence of cough and bronchial responsiveness that may cause further deterioration of patients with impaired pulmonary function.

OBJECTIVE

To review the available literature on the incidence of cough and bronchial responsiveness associated with ACE-inhibitor therapy in patients with asthma, chronic obstructive pulmonary disease (COPD), and congestive heart failure (CHF).

DATA SOURCES

Literature was accessed through MEDLINE (1985-September 2001). Key search terms included cough, bronchospasm, asthma, congestive heart failure, chronic obstructive pulmonary disease, ACE inhibitors, and angiotensin II receptor blockers.

DATA SYNTHESIS

The literature reports several cases of increased bronchial responsiveness associated with ACE inhibitors. Larger, controlled studies evaluating the increased risk in patients with pulmonary dysfunction are limited. Data from these trials are summarized in this article.

CONCLUSIONS

The literature shows that patients with primary airway disease such as asthma and COPD are not at an increased risk of developing cough or bronchoconstriction as a result of ACE-inhibitor therapy. Despite the ability of ACE inhibitors to improve exercise tolerance, perfusion, and gas transfer, patients with CHF may be at higher risk of developing cough than the general population. Whether this cough is attributed to ACE inhibition or increased left-ventricular dysfunction remains uncertain. If increased bronchial responsiveness does occur, angiotensin II receptor antagonists are another reasonable option.

Angiotensin II receptor antagonists role in arterial hypertension

Angiotensin II receptor blockers represent a class of effective and well tolerated orally active antihypertensive drugs. Activation of AT(1) receptors leads to vasoconstriction, stimulation of the release of catecholamines and antidiuretic hormone and promote growth of vascular and cardiac muscle. AT(1) receptor blockers antagonise all those effects. Losartan was the first drug of this class marketed, shortly followed by valsartan, irbesartan, telmisartan, candesartan, eprosartan and others on current investigation. All these drugs have the common properties of blockading the AT(1) receptor thereby relaxing vascular smooth muscle, increase salt excretion, decrease cellular hypertrophy and induce antihypertensive effect without modifying heart rate or cardiac output. Most of the AT(1) receptor blockers in use controlled blood pressure during the 24 h with a once-daily dose, without evidence of producing tolerance to the antihypertensive effect and being with low incidence of side effects even at long term use. Monotherapy in mild-to-moderate hypertension controls blood pressure in 40 to 50% of these patients; when a low dose of thiazide diuretic is added, 60-70% of patients are controlled. The efficacy is similar to angiotensin-converting enzyme (ACE) inhibitors, diuretics, calcium antagonists and beta-blocking agents. AT(1) receptor blockers are specially indicated in patients with hypertension who are being treated with ACE inhibitors and developed side effects such as, cough or angioedema. The final position in the antihypertensive therapy in this special population and other clinical situations, such as left ventricular hypertrophy, heart failure, diabetes mellitus and renal disease, has to be determined in large prospective clinical trials, some of which are now being conducted and seem promising.

The effect duration of candesartan cilexetil once daily, in comparison with enalapril once daily, in patients with mild to moderate hypertension

OBJECTIVE

To determine the antihypertensive efficacy, effect duration and safety of the angiotensin II type 1 receptor blocker candesartan cilexetil and the angiotensin converting enzyme inhibitor enalapril once daily in patients with mild to moderate hypertension.

METHODS

A multicenter, randomised, double-blind parallel group study was performed in Finland, France, the Netherlands, Spain and Sweden. Three-hundred-and-ninety-five men and women in the age range 20-80 years with primary hypertension were randomised to an 8-week double-blind treatment period with either candesartan cilexetil 8-16 mg or enalapril 10-20 mg once daily, with forced dose titration after 4 weeks. Non-invasive ambulatory blood pressure was measured for 36 h at baseline and after 8 weeks. The primary efficacy variable was the change in mean diastolic and systolic ambulatory blood pressure 22-24 h post-dose.

RESULTS

There was a significant difference in the adjusted mean difference for the change from baseline to week 8 between candesartan cilexetil and enalapril 22-24 h post-dose by -3.5 mmHg (95% confidence interval, CI: -6.8 to -0.3 mmHg; p < 0.032) in ambulatory systolic blood pressure and -3.0 mmHg (95% CI: -5.1 to -0.8 mmHg; p < 0.008) in ambulatory diastolic blood pressure. There was a significant difference in adjusted mean daytime ambulatory blood pressure 24-36 h post-dose by -4.2 mmHg (95% CI: -6.8 to -1.6 mmHg; p < 0.002)/-3.5 mmHg (95% CI: -5.1 to -1.8 mmHg; p < 0.001). Both drugs were generally well tolerated.

CONCLUSION

The results of the present study suggest that advantages may be attributed to the use of candesartan cilexetil, as compared to enalapril in the treatment of patients with essential hypertension. In comparison with enalapril 20 mg, candesartan cilexetil 16 mg more effectively lowered blood pressure at trough and in particular on the day following the day after the last dose.

Quality of life and cough on antihypertensive treatment: a randomised trial of eprosartan, enalapril and placebo

The objective of this study was to compare the quality of life and incidence of dry cough with the angiotensin II antagonist eprosartan, the ACE-inhibitor enalapril, and placebo, in hypertensive patients with a history of ACE-inhibitor cough. The study was a multicentre, randomised, double-blind, parallel group controlled trial. A total of 136 patients judged to have ACE-inhibitor cough during single-blind enalapril treatment which was lost during a subsequent placebo washout phase, were randomised to receive either eprosartan 300 mg twice daily, or enalapril 20 mg once daily, or placebo for 6 weeks. Self-completion questionnaires assessing quality of life and cough were examined at baseline and end of study. At study end point 23% of patients in the enalapril group and 5% in the eprosartan and placebo groups reported cough (which included definite, probable and possible coughs) (P = 0.02). After adjusting for multiple comparisons, the eprosartan group was not significantly different from either placebo or enalapril. There were no significant differences in the Psychological General Wellbeing Index (PGWB). In conclusion the incidence of self-reported cough on eprosartan was similar to that on placebo, and lower than on enalapril but this difference was not significant when adjustments were made for multiple comparisons. There were no differences in quality of life.

Efficacy and safety of angiotensin II receptor blockers in elderly patients with mild to moderate hypertension

The role of the renin-angiotensin-aldosterone system in the pathogenesis of hypertensive disease has long been recognized, and the interruption of this cascade with angiotensin-converting enzyme-I has been beneficial in the management of hypertension. Recently, a new class of drugs, the angiotensin receptor blockers, emerged, enlarging the antihypertensive armamentarium. Since elderly patients are more prone to adverse drug reactions, in this paper we review several trials, most of which were of short duration, on the efficacy and safety of angiotensin receptor blockers in the geriatric population with mild to moderate hypertension. These studies established that the drugs are well-tolerated, safe, and in most instances as efficacious as other classes of antihypertensive medications. Combination therapy with angiotensin receptor blockers and hydrochlorothiazide was additive, without any significant effect on the safety profile.

Rationale for angiotensin II receptor blockers in patients with low-renin hypertension

African Americans outrank other ethnic groups in the United States in prevalence, early onset, and severity of hypertension. Furthermore, African Americans suffer the highest rates of mortality from cardiovascular, cerebrovascular, and end-stage renal disease. The recently concluded Heart Outcomes Prevention Evaluation (HOPE) study reports that the angiotensin-converting enzyme (ACE) inhibitor ramipril significantly reduced morbidity and mortality in a broad range of patients at high risk for cardiovascular events. These results strengthen the case for increasing the use of ACE inhibitor therapy. In accord with the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) guidelines, antihypertensive monotherapy for African Americans is based on the known ability of diuretics and calcium channel blockers to produce greater reductions in blood pressure in this population than those attainable with beta blockers and ACE inhibitors. The national guidelines also suggest ACE inhibitors for all hypertensive patients with left ventricular dysfunction or nephropathy, which implies that African Americans must cross a clinical threshold to become candidates for these agents. The rationale for delaying ACE inhibitor therapy is due in part to a perceived unique pathobiology in hypertensive African Americans: an excess prevalence of salt sensitivity, hypervolemia, and low plasma renin activity (PRA). At first glance, it would seem intuitive to avoid agents that further depress the renin-angiotensin system (RAS) and choose agents that reduce plasma volume. However, most hypertensive African Americans are not hypovolemic. Furthermore, dietary sodium restriction and diuretic therapy raise PRA and improve the response to ACE inhibitors. The overall aim of this article is to explain the rationale for expanded use of drugs that block the RAS in African Americans and low-renin populations.

Therapeutic trials comparing angiotensin converting enzyme inhibitors and angiotensin II receptor blockers

Two independent pharmacologic methods of specifically interfering with the renin-angiotensin-aldosterone system have been brought to the marketplace: angiotensin converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs). These agents have the potential not only to be very widely used for a broad variety of clinical indications but also to compete against each other as treatments for hypertension, heart failure, renal impairment, and other conditions. Many short-term comparative studies of these two classes of drugs have now been completed. Most have focused on surrogate endpoints, such as blood pressure, renal function, or cough. These studies have generally concluded that ARBs are better tolerated but that the two drug classes otherwise have similar efficacy. The largest clinical trial comparing ARBs and ACE inhibitors thus far completed, Evaluation of Losartan in the Elderly (ELITE 2), failed to confirm the results of a smaller study; it did not demonstrate a significant improvement in outcomes (death or hospitalization for heart failure) with an ARB used alone, despite better tolerability. Many longer-term outcome studies with survival endpoints are under way, but most will compare the combination against an ACE inhibitor alone. These studies will define the optimal use of these agents in medicine for decades to come.

Recent insight into therapy of congestive heart failure: focus on ACE inhibition and angiotensin-II antagonism

One possible intervention to interrupt the deleterious effects of the renin-angiotensin system is suppression of angiotensin II (Ang II) formation by inhibition of angiotensin-converting enzyme (ACE). However, ACE inhibition incompletely suppresses Ang II formation and also leads to accumulation of bradykinin. Angiotensin II type 1 (AT1) receptors are believed to promote the known deleterious effects of Ang II. Therefore, AT1 receptor antagonists have been recently introduced into therapy for hypertension and congestive heart failure (CHF). Although there are significant differences between the effects of AT1 receptor antagonists and ACE inhibitors including the unopposed stimulation of angiotensin II type 2 (AT2) receptors by AT1 receptor antagonists, the discussion of whether ACE inhibitors, AT1 receptor antagonists or the combination of both are superior in the pharmacotherapy of CHF is still largely theoretical. Accordingly, AT1 receptor antagonists are still investigational. Angiotensin-converting enzyme inhibitors remain first line therapy in patients with CHF due to systolic dysfunction. However, in patients not able to tolerate ACE inhibitor induced side effects, in particular cough, AT1 receptor antagonism is a good alternative. In clinical practice, emphasis should be placed on increasing the utilization of ACE inhibitors, as more than 50% of patients with CHF do not receive ACE inhibitors. In addition, the majority of those on ACE inhibitors receive doses lower than the dosage used in the large clinical trials. Although not yet completely proved, it is likely that high doses of ACE inhibition are superior to low doses with respect to prognosis and symptoms.

Efficacy and safety of telmisartan, a selective AT1 receptor antagonist, compared with enalapril in elderly patients with primary hypertension. TEES Study Group

OBJECTIVE

To assess the antihypertensive efficacy and safety of the novel AT1 receptor antagonist, telmisartan, compared with that of enalapril in elderly patients with mild to moderate hypertension.

DESIGN

A 26-week, multicenter, double-blind, parallel-group, dosage titration study.

METHODS

A total of 278 patients aged > or = 65 years were randomized to eithertelmisartan or enalapril once a day. The telmisartan dosage was increased from 20 to 40-80 mg and that of enalapril from 5 to 10-20 mg at 4-week intervals until trough supine diastolic blood pressure was < 90 mmHg. After 12 weeks, hydrochlorothiazide at 12.5-25 mg once a day was added to the treatment regimen of those patients not controlled on monotherapy.

RESULTS

Both treatments lowered blood pressure in a comparable and clinically meaningful manner. The adjusted mean changes from baseline in supine diastolic blood pressure at trough were -12.8 mmHg for telmisartan and -11.4 mmHg for enalapril (P = 0.074). Mean changes in supine systolic blood pressure were -22.1 mmHg for telmisartan and -20.1 mmHg for enalapril (P = 0.350). Overall, 63 and 62% of patients responded to telmisartan and enalapril, respectively, with a supine diastolic blood pressure of < 90 mmHg. Both regimens provided effective blood pressure lowering over the 24 h dosing interval, as determined by ambulatory blood pressure monitoring. Both regimens were well tolerated; however, patients on the enalapril regimen had more than double the incidence of treatment-related cough compared with those on the telmisartan regimen (16 versus 6.5%).

CONCLUSIONS

These results demonstrate that telmisartan is well tolerated and is at least as effective as enalapril in treating elderly patients with mild to moderate hypertension.

New insights into the treatment of hypertension

1. The choice of initial pharmacological therapy is one area where the different hypertension management guidelines vary in recommending either the use of diuretics and beta-blockers as preferred drugs or choosing from any of the five major classes of antihypertensives. 2. Improvement in cardiovascular morbidity and mortality may have been shown most conclusively with diuretics and beta-blockers, but the effects on coronary events with these drugs were less than predicted and the other agents have a number of theoretical advantages. 3. Recent worries regarding the possible adverse effects of calcium antagonists have led to a reappraisal of the risks and benefits of these drugs and antihypertensives in general. 4. Many patients, particularly the elderly, have other conditions that influence the choice of first-line therapy and ethnic variations in the effects of hypertension or the efficacy or side effects of drugs should also be taken into account. 5. There is considerable heterogeneity within the major categories of antihypertensive drugs, so it is important to distinguish the different subgroups, dosages and formulations that may be used.