Are all angiotensin-converting enzyme inhibitors interchangeable?

Drugs Becoming Generics-The Impact of Genericization on the Market Performance of Antihypertensive Active Pharmaceutical Ingredients

To explore long-term changes in intra and inter-class choices between generic compounds, this paper investigates the market trends of two antihypertensive drug classes that have closely related pharmacological mechanisms—angiotensin convertase enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs). We analysed the development of ACEI and ARB markets between 2001 and 2016 in nine European countries, covering the genericization transition periods of both therapeutic groups. The analysis was undertaken on the level of the active pharmaceutical ingredients (API) and focused on international and country-specific diffusion patterns. Comparison of ARB and ACEI therapies shows that although ARBs became off-patent during the observed period, and have a clinical advantage in terms of the adverse event profile over ACEIs, the increasing dominance of ARBs cannot be identified. One explanation is that ACEI therapies became generics earlier, relocating competition to the level of brands, while competition among ARBs remained at the level of the APIs. As for intra-class drug preferences, it was observed that the long-term trends show that ramipril outperformed its ACEI competitors, even though the kinetics and the rank order of preferred active compounds were inconsistent among markets. The diffusion of clinically preferable therapies seems to be ultimately supported by generic entries. In Eastern European countries, the emergence of generic markets has not only improved access to ACE inhibitors and ARBs, but has been a prerequisite for changing preferences. In contrast, genericization resulted in the relative anchoring of prior, branded era-based preferences in some Western European countries, which may be attributed to the role of the cessation of promotion and the fixity of prescription behaviour.

Observational Study of Brain Atrophy and Cognitive Decline Comparing a Sample of Community-Dwelling People Taking Angiotensin Converting Enzyme Inhibitors and Angiotensin Receptor Blockers Over Time

BACKGROUND

Hypertension is an established risk factor for dementia. However, it is unclear whether there are differential effects of angiotensin converting enzyme inhibitor (ACEi) or angiotensin receptor blockers (ARB) on brain health. In human observational studies, the evidence for superiority of either agent remains unclear.

OBJECTIVE

To compare brain atrophy and cognitive decline between people treated with ACEi or ARB.

METHODS

Participants aged 55-90 years without dementia had brain magnetic resonance imaging and neuropsychological assessments performed at 3 time points. The sample was enriched with people with type 2 diabetes (T2D). Multivariable mixed models were used to examine longitudinal associations of antihypertensive medication class with change in cognition and total brain volume.

RESULTS

Of 565 people with longitudinal data, there were 163 on ACEi (mean age 69.9 years, T2D:64% with) and 125 on ARB (mean age 69.6 years, T2D:62%) at baseline. The baseline characteristics of those taking either an ACEi or ARB were similar with regards to age, sex, blood pressure control, and vascular risk factors. The mean duration of follow up was 3.2 years. The baseline association of ACEi and ARB use with total brain volume was similar in both groups. However, those taking an ARB had a slower rate of brain atrophy than those taking an ACEi (p = 0.031). Neither ACEi nor ARB use was associated with baseline cognitive function or cognitive decline.

CONCLUSIONS

These results support the theory that ARB may be preferable to ACEi to reduce brain atrophy. The mechanisms underlying this differential association warrant further investigation.

Pharmacovigilance in patients with diabetes: A data-driven analysis identifying specific RAS antagonists with adverse pulmonary safety profiles that have implications for COVID-19 morbidity and mortality

OBJECTIVES

The current demographic information from China reports that 10%-19% of patients hospitalized with coronavirus disease (COVID-19) were diabetic. Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) are considered first-line agents in patients with diabetes because of their nephroprotective effects, but administration of these drugs leads to upregulation of angiotensin-converting enzyme 2 (ACE2), which is responsible for the viral entry of severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2). Data are lacking to determine what pulmonary effects ACEIs or ARBs may have in patients with diabetes, which could be relevant in the management of patients infected with SARS-CoV-2. This study aims to assess the prevalence of pulmonary adverse drug effects (ADEs) in patients with diabetes who were taking ACEI or ARBs to provide guidance as to how these medications could affect outcomes in acute respiratory illnesses such as SARS-CoV-2 infection.

METHODS

1DATA, a unique data platform resulting from collaboration across veterinary and human health care, used an intelligent medicine recommender system (1DrugAssist) developed using several national and international databases to evaluate all ADEs reported to the Food and Drug Administration for patients with diabetes taking ACEIs or ARBs.

RESULTS

Mining of this data elucidated the proportion of a cluster of pulmonary ADEs associated with specific medications in these classes, which may aid health care professionals in understanding how these medications could worsen or predispose patients with diabetes to infections affecting the respiratory system, specifically COVID-19. Based on this data mining process, captopril was found to have a statistically significantly higher incidence of pulmonary ADEs compared with other ACEIs (P = 0.005) as well as ARBs (P = 0.012), though other specific drugs also had important pulmonary ADEs associated with their use.

CONCLUSION

These analyses suggest that pharmacists and clinicians will need to consider the specific medication's adverse event profile, particularly captopril, on how it may affect infections and other acute disease states that alter pulmonary function, such as COVID-19.

Long-term effect of the perindopril/indapamide/amlodipine single-pill combination on left ventricular hypertrophy in outpatient hypertensive subjects

BACKGROUND

Most antihypertensive drugs used in monotherapy or in combination therapy reduce the left ventricular mass index (LVMI). However, little is known about the effects on LVMI of a triple fixed-dose combination (TFC) therapy, containing in a single pill an angiotensin-converting enzyme inhibitor (ACEI), a diuretic and a calcium channel blocker (CCB).

METHODS

In this prospective open-label study, 92 patients with essential hypertension were randomized to treatment with a TFC of perindopril/indapamide/amlodipine at different doses or a triple free combination therapy (FCT) including ACEI/diuretic/CCB. Office blood pressure (BP) measurement, 24 h-ambulatory BP monitoring and echocardiography were performed at baseline and during a 14-month follow-up. The BP variability (BPV) over 24 h was calculated as ± standard deviation of the daytime systolic BP. Differences between office and monitored BP and LVMI were evaluated by ANOVA for repeated measures.

RESULTS

A significant BP-lowering effect was observed for both treatments. At follow-up, BPV was reduced in both the treatment groups vs. the baseline (14.0±1.5 vs. 17.0±1.8 and 16.2±2.1 vs. 17.6±2.3, respectively), but it was lower in the TFC vs. the FCT group (14.0±1.5 vs. 16.1±2.2, P < 0.05). LVMI was lower in both the treatment groups, but the change was greater for TFC vs. FCT (-8.3±4.9% vs. -2.0 ±2.1%, P < 0.0001). Left ventricular hypertrophy (LVH) regression was greater in the TFC vs. the FCT group (43.5% vs. 30.4%, P < 0.05).

CONCLUSIONS

Independently of BP values achieved, the antihypertensive TFC therapy was more effective than FCT in LVMI reduction and LVH regression, possibly related to drugs' intrinsic properties and to BPV modulation.

The Coming of Age of the Angiotensin Hypothesis in Alzheimer's Disease: Progress Toward Disease Prevention and Treatment?

There is wide recognition of a complex association between midlife hypertension and cardiovascular disease and later development of Alzheimer’s disease (AD) and cognitive impairment. While significant progress has been made in reducing rates of mortality and morbidity due to cardiovascular disease over the last thirty years, progress towards effective treatments for AD has been slower. Despite the known association between hypertension and dementia, research into each disease has largely been undertaken in parallel and independently. Yet over the last decade and a half, the emergence of converging findings from pre-clinical and clinical research has shown how the renin angiotensin system (RAS), which is very important in blood pressure regulation and cardiovascular disease, warrants careful consideration in the pathogenesis of AD. Numerous components of the RAS have now been found to be altered in AD such that the multifunctional and potent vasoconstrictor angiotensin II, and similarly acting angiotensin III, are greatly altered at the expense of other RAS signaling peptides considered to contribute to neuronal and cognitive function. Collectively these changes may contribute to many of the neuropathological hallmarks of AD, as well as observed progressive deficiencies in cognitive function, while also linking elements of a number of the proposed hypotheses for the cause of AD. This review discusses the emergence of the RAS and its likely importance in AD, not only because of the multiple facets of its involvement, but also perhaps fortuitously because of the ready availability of numerous RAS-acting drugs, that could be repurposed as interventions in AD.

Observational studies of treatment effectiveness: worthwhile or worthless?

Observational studies which evaluate effectiveness are often viewed with skepticism owing to the fact that patients are not randomized to treatment, meaning that results are more prone to bias. Therefore, randomized controlled trials remain the gold standard for evaluating treatment effectiveness. However, it is not always possible to conduct randomized trials. This may be due to financial constraints, for example, in identifying funding for a randomized trial for medicines that have already gained market authorization. There can also be challenges with recruitment, for example, of people with rare conditions or in hard-to-reach population subgroups. This is why observational studies are still needed. In this manuscript, we discuss how researchers can mitigate the risk of bias in the most common type of observational study design for evaluation of treatment effectiveness, the cohort study. We outline some key issues that warrant careful consideration at the outset when the question is being developed and the cohort study is being designed. We focus our discussion on the importance of deciding when to start follow-up in a study, choosing a comparator, managing confounding and measuring outcomes. We also illustrate the application of these considerations in a more detailed case study based on an examination of comparative effectiveness of two antidiabetic treatments using data collected during routine clinical practice.

Drug therapies in chronic heart failure: a focus on reduced ejection fraction

There are multiple evidence-based drug treatments for chronic heart failure (HF), both disease-modifying agents and those for symptom control. The majority of the evidence base supports drugs used in HF with reduced left ventricular ejection fraction. The mainstay of disease modification involves manipulation of neurohormonal activation that occurs in HF. In addition to established angiotensin-converting enzyme inhibitors, beta blockers and mineralocorticoid receptor antagonists (MRAs), newer agents are now available such as the angiotensin receptor neprilysin inhibitors. Achieving the optimal drug regimen is complex and best performed by a specialist heart failure team. We aim to provide a comprehensive overview of contemporary drug therapies in chronic heart failure, as well as practical guidance for their use. There is a focus on treating patients with challenging comorbidities such as hypotension and chronic kidney disease (CKD), where a thorough understanding of drug therapy is essential. Multiple trials assessing the benefits of new therapies in HF, such as intravenous iron, are also ongoing.

A review of the traditional and modern uses of Salvadora persica L. (Miswak): Toothbrush tree of Prophet Muhammad

ETHNOPHARMACOLOGICAL RELEVANCE

Salvadora persica L., also known as Arak (in Arabic) and Peelu (in Urdu), is the most common traditional source of tooth or chewing stick (miswak) highly recommended by Prophet Muhammad. To date, extensive studies have probed primarily into the validation of its traditional uses in oral care. Nonetheless, there is still a dearth of updated compilation and critical analysis of other potential ethnopharmacological properties of S. persica. This review therefore aims to provide an up-to-date detailed structured description of the traditional uses of S. persica and a critical analysis of its modern uses, highlighting its phytochemistry, pharmacological properties, and bioapplications.

MATERIALS AND METHODS

Various databases (Science Direct, PubMed, Wiley Online Library, and Google Scholar), books, and relevant primary sources were probed, surveyed, analysed, and included in this review. The literature cited in this review dated from 1979 to 2017.

RESULTS

S. persica was found to possess a plethora of bioactive compounds and broad pharmacological properties, including antimicrobial, antioxidant, enzyme inhibitory activity, antiulcer, anticonvulsant, sedative, analgesic, anti-inflammatory, hypoglycemic, hypolipidemic, antiosteoporosis, and antitumor activities. Studies also revealed the potential use of S. persica as a natural food preservative and a novel functional food ingredient. In addition, improvement in growth and reproductive performances have been observed by the introduction of S. persica in animal feed. Lastly, S. persica has also been used in the green synthesis of nanoparticles showing potential biotechnological applications.

CONCLUSION

S. persica showed a wide scope of application and its uses have been extended far beyond the initial traditional uses of its roots, stems, and twigs in oral care. We found a number of other ethnopharmacological uses and potential bioapplications of different parts of S. persica that warrants further investigations. Though widely studied using several in vitro and in vivo models, and tested clinically for oral hygiene mainly, several gaps and research priorities have been identified which needs to be addressed in future.

Meta-Analysis of Randomized Trials on the Efficacy and Safety of Angiotensin-Converting Enzyme Inhibitors in Patients ≥65 Years of Age

The comparative efficacy and safety of angiotensin-converting enzyme inhibitors (ACEIs) with other agents in patients ≥65 years of age with cardiovascular diseases or at-risk are unknown. Electronic databases were systematically searched to identify all randomized controlled trials that compared ACEIs with control (placebo or active) and reported long-term cardiovascular outcomes. We required the mean age of patients in the studies to be ≥65 years. Random-effects model was used to pool study results. Sixteen trials with 104,321 patients and a mean follow-up of 2.9 years were included. Compared with placebo, ACEIs significantly reduced all outcomes except stroke. Compared with active controls, ACEIs had similar effect on all-cause mortality (relative risk [RR] 0.99, 95% confidence interval [CI] 0.95 to 1.03), cardiovascular mortality (RR 0.99, 95% CI 0.93 to 1.04), heart failure (RR 0.97, 95% CI 0.91 to 1.03), myocardial infarction (RR 0.94, 95% CI 0.88 to 1.00), and stroke (RR 1.07, 95% CI 0.99 to 1.15). ACEIs were associated with an increased risk of angioedema (RR 2.79, 95% CI 1.05 to 7.42), whereas risk for hypotension and renal insufficiency was similar compared with active controls. Meta-regression analysis showed that the effect of ACEIs on outcomes remained consistent with age increasing ≥65 years. Sensitivity analysis excluding trials comparing ACEIs with angiotensin receptor blockers and heart failure trials yielded similar results, except for reduction in myocardial infarction. In conclusion, the efficacy of ACEIs was similar to active controls for mortality outcomes. Compared with placebo, there was evidence for reduction in cardiovascular outcomes; however, ACEIs failed to prevent stroke and increased the risk of angioedema, hypotension, and renal failure.

Pharmacodynamic Impact of Carboxylesterase 1 Gene Variants in Patients with Congestive Heart Failure Treated with Angiotensin-Converting Enzyme Inhibitors

BACKGROUND

Variation in the carboxylesterase 1 gene (CES1) may contribute to the efficacy of ACEIs. Accordingly, we examined the impact of CES1 variants on plasma angiotensin II (ATII)/angiotensin I (ATI) ratio in patients with congestive heart failure (CHF) that underwent ACEI dose titrations. Five of these variants have previously been associated with drug response or increased CES1 expression, i.e., CES1 copy number variation, the variant of the duplicated CES1 gene with high transcriptional activity, rs71647871, rs2244613, and rs3815583. Additionally, nine variants, representatives of CES1Var, and three other CES1 variants were examined.

METHODS

Patients with CHF, and clinical indication for ACEIs were categorized according to their CES1 genotype. Differences in mean plasma ATII/ATI ratios between genotype groups after ACEI dose titration, expressed as the least square mean (LSM) with 95% confidence intervals (CIs), were assessed by analysis of variance.

RESULTS

A total of 200 patients were recruited and 127 patients (63.5%) completed the study. The mean duration of the CHF drug dose titration was 6.2 (SD 3.6) months. After ACEI dose titration, there was no difference in mean plasma ATII/ATI ratios between subjects with the investigated CES1 variants, and only one previously unexplored variation (rs2302722) qualified for further assessment. In the fully adjusted analysis of effects of rs2302722 on plasma ATII/ATI ratios, the difference in mean ATII/ATI ratio between the GG genotype and the minor allele carriers (GT and TT) was not significant, with a relative difference in LSMs of 0.67 (95% CI 0.43-1.07; P = 0.10). Results of analyses that only included enalapril-treated patients remained non-significant after Bonferroni correction for multiple parallel comparisons (difference in LSM 0.60 [95% CI 0.37-0.98], P = 0.045).

CONCLUSION

These findings indicate that the included single variants of CES1 do not significantly influence plasma ATII/ATI ratios in CHF patients treated with ACEIs and are unlikely to be primary determinants of ACEI efficacy.

Pharmacogenetic Risk Stratification in Angiotensin-Converting Enzyme Inhibitor-Treated Patients with Congestive Heart Failure: A Retrospective Cohort Study

Background

Evidence for pharmacogenetic risk stratification of angiotensin-converting enzyme inhibitor (ACEI) treatment is limited. Therefore, in a cohort of ACEI-treated patients with congestive heart failure (CHF), we investigated the predictive value of two pharmacogenetic scores that previously were found to predict ACEI efficacy in patients with ischemic heart disease and hypertension, respectively. Score A combined single nucleotide polymorphisms (SNPs) of the angiotensin II receptor type 1 gene (rs275651 and rs5182) and the bradykinin receptor B1 gene (rs12050217). Score B combined SNPs of the angiotensin-converting enzyme gene (rs4343) and ABO blood group genes (rs495828 and rs8176746).

Methods

Danish patients with CHF enrolled in the previously reported Echocardiography and Heart Outcome Study were included. Subjects were genotyped and categorized according to pharmacogenetic scores A and B of ≤1, 2 and ≥3 each, and followed for up to 10 years. Difference in cumulative incidences of cardiovascular death and all-cause death were assessed by the cumulative incidence estimator. Survival was modeled by Cox proportional hazard analyses.

Results

We included 667 patients, of whom 80% were treated with ACEIs. Differences in cumulative incidences of cardiovascular death (P = 0.346 and P = 0.486) and all-cause death (P = 0.515 and P = 0.486) were not significant for score A and B, respectively. There was no difference in risk of cardiovascular death or all-cause death between subjects with score A ≤1 vs. 2 (HR 1.03 [95% CI 0.79–1.34] and HR 1.11 [95% CI 0.88–1.42]), score A ≤1 vs. ≥3 (HR 0.80 [95% CI 0.59–1.08] and HR 0.91 [95% CI 0.70–1.20]), score B ≤1 vs. 2 (HR 1.02 [95% CI 0.78–1.32] and HR 0.98 [95% CI 0.77–1.24]), and score B ≤1 vs. ≥3 (HR 1.03 [95% CI 0.75–1.41] and HR 1.05 [95% CI 0.79–1.40]), respectively.

Conclusions

We found no association between either of the analyzed pharmacogenetic scores and fatal outcomes in ACEI-treated patients with CHF.

Use of different types of angiotensin converting enzyme inhibitors and mortality in systolic heart failure

BACKGROUND

Angiotensin converting enzyme-inhibitors (ACEIs) are the first-line treatment for patients with heart failure (HF) with reduced ejection fraction (EF). The benefit of ACEIs in HF is regarded as a class effect and different types of agents are used interchangeably. However, evidence on the comparable effectiveness of different ACEIs is scarce. We conducted a registry-based cohort study to assess all-cause mortality associated with the use of enalapril, perindopril, and trandolapril, as compared with ramipril, in patients with systolic HF.

METHODS

Patients with systolic HF (EF ≤40%), 2003-2012, were identified using the Danish HF Registry. New users of enalapril (n=1807), perindopril (n=1064), ramipril (n=3270), or trandolapril (n=1150), who started treatment within 60days of first-time hospital diagnosis of HF, were selected for inclusion. Subgroup analyses were conducted by sex, age, NYHA-level, EF, and ischemic heart disease. All analyses were adjusted for empirical risk scores for mortality.

RESULTS

During follow-up, 291 deaths were observed among users of enalapril (incidence rate per 100person-years [IR], 10.1), 212 among users of perindopril (IR, 10.5), 568 among users of ramipril (IR, 10.6), and 251 among users of trandolapril (IR, 12.1). No significant differences in all-cause mortality were observed with the use of enalapril (adjusted hazard ratio [aHR] 0.95, 95% CI 0.82-1.10), perindopril (aHR 1.07, 95% CI 0.92-1.26), or trandolapril (aHR 1.08, 95% CI 0.93-1.26), as compared with ramipril. No significant differences were observed in subgroup analyses.

CONCLUSIONS

These findings suggest equal effect of different types of ACEIs on mortality in systolic HF.

Mitigation of experimental radiation nephropathy by renin-equivalent doses of angiotensin converting enzyme inhibitors

PURPOSE

We tested five different angiotensin converting enzyme inhibitors (ACEI) as mitigators of experimental radiation nephropathy at drug doses calibrated to the plasma renin activity (PRA). This was done to determine whether all ACEI had the same efficacy as mitigators of radiation nephropathy when used at drug doses that gave equivalent suppression of the renin angiotensin system.

METHOD

10 Gy total body irradiation with bone marrow transplantation was used to cause radiation nephropathy in barrier-maintained rats. Equivalent ACEI doses were determined based on their effect to inhibit angiotensin converting enzyme (ACE) and raise the PRA in unirradiated animals.

RESULTS

PRA-equivalent doses were found for captopril, lisinopril, enalapril, ramipril and fosinopril. These doses overlap the human doses of these drugs on a body surface area basis. All ACE inhibitors, except fosinopril, mitigated radiation nephropathy; captopril was a somewhat better mitigator than lisinopril, enalapril or ramipril.

CONCLUSIONS

Most, but not all, ACEI mitigate radiation nephropathy at doses that overlap their clinically-used doses (on a body surface area basis). Fosinopril is known to be an ineffective mitigator of radiation pneumonitis, and it also does not mitigate radiation nephropathy. These pre-clinical data are critical in planning human studies of the mitigation of normal tissue radiation injury.

Angiotensin-converting enzyme inhibitors and incidence of mild cognitive impairment. The Italian Longitudinal Study on Aging

Midlife elevated blood pressure and hypertension contribute to the development of Alzheimer's disease (AD) and overall dementia. We sought to estimate whether angiotensin-converting enzyme inhibitors (ACE-Is) reduced the risk of developing mild cognitive impairment (MCI) in cognitively normal individuals. In the Italian Longitudinal Study on Aging, we evaluated 1,445 cognitively normal individuals treated for hypertension but without congestive heart failure from a population-based sample from eight Italian municipalities with a 3.5-year follow-up. MCI was diagnosed with current clinical criteria. Dementia, AD, and vascular dementia were diagnosed based on DSM-IIIR criteria, NINCDS-ADRDA criteria, and ICD-10 codes. Among 873 hypertension-treated cognitively normal subjects, there was no significant association between continuous exposure to all ACE-Is and risk of incident MCI compared with other antihypertensive drugs [hazard ratio (HR), 0.45, 95% confidence interval (CI), 0.16-1.28]. Captopril exposure alone did not significantly modify the risk of incident MCI (HR, 1.80, 95% CI, 0.39-8.37). However, the enalapril sub-group alone (HR, 0.17, 95% CI, 0.04 -0.84) or combined with the lisinopril sub-group (HR, 0.27, 95% CI, 0.08-0.96), another ACE-I structurally related to enalapril and with similar potency, were associated with a reduced risk of incident MCI. Study duration exposure to ACE-Is as a "class" was not associated with incident MCI in older hypertensive adults. However, within-class differences linked to different chemical structures and/or drug potencies may exist, with a possible effect of the enalapril and lisinopril sub-groups in reducing the risk of incident MCI.

Biosimilar epoetins and other "follow-on" biologics: update on the European experiences

After the patents of biopharmaceuticals have expired, based on specific regulatory approval pathways copied products ("biosimilars" or "follow-on biologics") have been launched in the EU. This article summarizes experiences with hematopoietic medicines, namely the epoetins (two biosimilars traded under five different brand names) and the filgrastims (two biosimilars, six brand names). Physicians and pharmacists should be familiar with the legal and pharmacological specialities of biosimilars: The production process can differ from that of the original, clinical indications can be extrapolated, glycoproteins contain varying isoforms, the formulation may differ from the original, and biopharmaceuticals are potentially immunogenic. Only on proof of quality, efficacy and safety, biosimilars are a viable option because of their lower costs.

Update on the use of trandolapril in the management of cardiovascular disorders

Trandolapril is a well known angiotensin converting enzyme (ACE) inhibitor with many cardiovascular (CV) indications. The objectives of this article are to review the pharmacokinetics and pharmacodynamics properties of trandolapril and to focus on its clinical relevance in cardiovascular medicine. Various populations have been studied in large clinical trials including patients with congestive heart failure (CHF) after an acute myocardial infarction (AMI), diabetics, patients with hypertension (HTN), stable coronary artery disease (CAD) and prevention of proteinuria. Long-term treatment with trandolapril in patients with reduced left ventricular function soon after AMI significantly reduced the risk of overall mortality, mortality from CV causes, sudden death, and the development of severe CHF. Treatment with trandolapril after AMI complicated by left ventricular dysfunction appears to be of considerable importance in patients with diabetes mellitus by saving lives and substantially reducing the risk of progression to severe CHF as well. Moreover, trandolapril reduces progression to proteinuria in high-risk patients. Some of the advantages of trandolapril over other ACE inhibitors are the wide spectrum of patient populations studied, the well established dosage and its proven trough-to-peak effect ratios permitting a safe once-a-day administration.

Effect of different angiotensin-converting-enzyme inhibitors on mortality among elderly patients with congestive heart failure

BACKGROUND

Existing clinical trial data do not address whether all angiotensin-converting-enzyme (ACE) inhibitors are similarly beneficial in improving survival and reducing the rate of readmission among patients with congestive heart failure. We sought to answer this question using administrative databases from Canada's 3 most populous provinces.

METHODS

Using linked hospital discharge and prescription claims databases in Quebec, Ontario and British Columbia, we identified all patients 65 years or older who were admitted to hospital because of congestive heart failure between Jan. 1, 1998, and Mar. 31, 2002, and who had not been admitted for the same reason in the 3 years preceding the study period. We analyzed the association between the type of ACE inhibitor prescribed within 30 days after discharge and subsequent mortality using Cox proportional hazards models. We then adjusted for demographic, clinical, physician and hospital-related variables, with additional time-dependent variables representing current drug use and dosage. We chose ramipril as the reference category for comparison with the other ACE inhibitors because it has increasingly been prescribed to patients with congestive heart failure.

RESULTS

A total of 43 316 patients with congestive heart failure filled prescriptions for ACE inhibitors within 30 days after discharge from hospital. Demographic, clinical and prescription-related characteristics were similar among users of each type of ACE inhibitor. In the time-dependent model, the mortality associated with 5 ACE inhibitors was similar to that with ramipril: adjusted hazard ratios (and 95% confidence intervals [CIs]) were 0.95 (0.89-1.02) for lisinopril, 0.92 (0.85-1.00) for fosinopril, 0.99 (0.88-1.11) for quinapril, 0.90 (0.77-1.06) for perindopril and 1.00 (0.80-1.24) for cilazapril. However, use of enalapril or captopril was associated with higher mortality compared with ramipril: adjusted hazard ratios (and 95% CIs) were 1.10 (1.04-1.16) for enalapril and 1.13 (1.01-1.26) for captopril.

INTERPRETATION

When prescribing ACE inhibitors to patients, physicians should consider a possible 10%-15% increase in mortality with captopril and enalapril compared with ramipril among patients with congestive heart failure.

Medicinal chemistry and therapeutic relevance of angiotensin-converting enzyme inhibitors

Chemical Basis of Drug Action (PHA337 and PHA447) is a required 2-semester course sequence taught to second-professional year pharmacy students at Creighton University in both the campus and distance-education pathways. The course emphasizes integration of previous content, critical thinking, and therapeutic relevance. The content and learning experiences are organized to transition the students' thinking through a constructive process that provides ample opportunities to recall and integrate previous knowledge, learn and apply new knowledge, establish a logical connection between the science and its therapeutic relevance, and finally to apply the science knowledge to predict clinical activity and clinical outcomes as can be expected in a patient. This manuscript is based on the angiotensin converting enzyme inhibitors as an illustration of how our course objectives are accomplished.

Rule-based standardised switching of drugs at the interface between primary and tertiary care

INTRODUCTION

Changes in drug treatment are frequently mandatory with hospital admission and discharge because hospital drug formularies are generally restricted to about 3000 drugs as compared to the many times this number - 62,000 in Germany - that are commercially available. Without computerised support, the process involved with switching drugs to a corresponding generic or a therapeutic equivalent is time-consuming and error-prone.

METHODS

We have developed and tested a standardised interchange algorithm for subsequent implementation into a computerised decision support system that switches drugs to the corresponding generic or a therapeutic equivalent if they are not listed on the hospital drug formulary.

RESULTS

The algorithm was retrospectively applied to the medication regimens of 120 patients (774 prescribed drugs containing 886 active ingredients) at their time of admission to surgical wards. Of the prescribed drugs, 52.8% (409/774) were part of the hospital drug formulary, thereby rendering a switch unnecessary. The 365 drugs not listed consisted of 392 active ingredients that were successfully switched to a corresponding generic (84.7%) or a therapeutic equivalent (10.2%). No specific switching procedures were defined for only 2.3% (20/886) of the active ingredients. In these cases, the drugs were either discontinued (4/20) or special drug classes, current diseases or co-medication required manual switching (8/20), or the drugs were continued unchanged and ordered from a wholesaler (8/20).

CONCLUSION

Using a standardised interchange algorithm, pre-admission drug regimens can successfully be switched to drugs on a hospital drug formulary. These findings suggest that a computerised decision support system will likely be useful to support this important practice.

Evaluation of networks of randomized trials

Randomized trials may be designed and interpreted as single experiments or they may be seen in the context of other similar or relevant evidence. The amount and complexity of available randomized evidence vary for different topics. Systematic reviews may be useful in identifying gaps in the existing randomized evidence, pointing to discrepancies between trials, and planning future trials. A new, promising, but also very much debated extension of systematic reviews, mixed treatment comparison (MTC) meta-analysis, has become increasingly popular recently. MTC meta-analysis may have value in interpreting the available randomized evidence from networks of trials and can rank many different treatments, going beyond focusing on simple pairwise-comparisons. Nevertheless, the evaluation of networks also presents special challenges and caveats. In this article, we review the statistical methodology for MTC meta-analysis. We discuss the concept of inconsistency and methods that have been proposed to evaluate it as well as the methodological gaps that remain. We introduce the concepts of network geometry and asymmetry, and propose metrics for the evaluation of the asymmetry. Finally, we discuss the implications of inconsistency, network geometry and asymmetry in informing the planning of future trials.

Rationale for Combining Blockers of the Renin-Angiotensin System

Blockade of the renin-angiotensin system (RAS) with angiotensin I-converting enzyme (ACE) inhibitors and AT1-receptor (AT1R) blockers has become one of the most successful therapeutic approaches in medicine. The question is no longer whether RAS inhibition helps, but rather how we can optimize inhibition to achieve optimal cardiovascular and renal protection. Indeed, numerous data have shown that the RAS is not blocked fully over 24 hours with current doses of RAS blockers because they trigger a counter-regulatory renin release that can offset pharmacologic inhibition of the RAS. This absence of full blockade may have clinical implications. Combination therapy with ACE inhibitors and AT1R antagonists thus has been proposed to inhibit the biological effects of the reactive renin release triggered by single-site RAS inhibition. By using this approach, numerous experimental and clinical studies have suggested that this combination therapy has additive or synergistic effects on blood pressure and on the prevention of cardiovascular and renal lesions. Although similar intensity of RAS blockade can be achieved by either combination therapy or by using high doses of an AT1-receptor antagonist given alone, the ACE inhibitor present in the combination interferes with the bradykinin-nitric oxide pathway and the N-acetyl-Ser-Asp-Lys-Pro metabolism, which both may have additional biological effects.

Angiotensin-converting enzyme inhibitors in acute myocardial infarction: a clinical approach

Angiotensin-converting enzyme inhibitor therapy has been shown to be effective in treating patients across the spectrum of cardiac disease. Utility has been demonstrated for both prevention and treatment. This article reviews the data regarding angiotensin-converting enzyme inhibitor therapy in acute myocardial infarction, with emphasis on determining what is known regarding the mode of administration, optimal timing for initiation of treatment, and whether patients can be identified who are most likely to benefit from treatment.

The landscape after PEACE: do all ACE inhibitors act in an identical way?

The results of the Prevention of Events with Angiotensin Converting Enzyme Inhibition (PEACE trial), involving patients with stable coronary heart disease, demonstrated that the angiotensin-converting enzyme (ACE) inhibitor trandolapril did not reduce cardiovascular mortality, or the incidence of fatal or non-fatal myocardial infarction. These results were in conflict with the vast majority of previously published large-scale trials, and could be seen to weaken confidence in ACE inhibitor therapy of ischaemic heart disease. This review article examines the results of PEACE in comparison with the other major trials in terms of the severity of the disease in the patients, the statistical power of the analyses, the doses of the agents used and the concept of a 'class effect' of the ACE inhibitors.

Hydrochlorothiazide increases plasma or tissue angiotensin-converting enzyme-inhibitor drug levels in rats with myocardial infarction: Differential effects on lisinopril and zofenopril

Sodium depletion with diuretics augments the efficacy of angiotensin-converting enzyme-inhibitor therapy for hypertension and renal dysfunction, and possibly for left ventricular dysfunction after myocardial infarction. Underlying mechanisms may involve altered angiotensin-converting enzyme-inhibitor pharmacokinetics. We hypothesized that the diuretic hydrochlorothiazide causes increased steady-state levels of the angiotensin-converting enzyme-inhibitors lisinopril and zofenopril in rats with myocardial infarction. Rats were subjected to coronary ligation to induce myocardial infarction. After 1 week, rats were randomized to 50 mg/kg/day hydrochlorothiazide or control treatment for 3 weeks. The last week, rats received lisinopril or zofenopril in equipotentent dosages (3.3 and 10 mg/kg/day, respectively). Rats were sacrificed at Tmax after the last dose of angiotensin-converting enzyme-inhibitor, and tissues were collected for analysis of drug concentrations. Lisinopril concentrations in plasma were significantly increased by hydrochlorothiazide, at unchanged tissue concentrations. This increase could be fully explained by decreased renal function, as evidenced by increased plasma creatinine levels (lisinopril + hydrochlorothiazide 82+/-5 microM versus lisinopril 61+/-5 microM, P < 0.001). In contrast, zofenoprilat levels in kidney and non-infarcted left ventricle were markedly increased by hydrochlorothiazide, whereas plasma concentrations were unchanged. Although hydrochlorothiazide tended to increase plasma creatinine in zofenopril-treated rats as well, this increase was less pronounced (zofenopril + hydrochlorothiazide 61+/-3 microM versus zofenopril 54+/-2 microM, P = 0.15). Hydrochlorothiazide increases steady-state angiotensin-converting enzyme-inhibitor drug levels, most likely by affecting their renal clearance. Notably, the lipophilic angiotensin-converting enzyme-inhibitor zofenopril accumulated in tissue, whereas the hydrophilic lisinopril increased in plasma. Whether combining different angiotensin-converting enzyme-inhibitors with hydrochlorothiazide translates into distinct clinical profiles requires further study.

Hypertension guidelines, meta-analyses and clinical trials: do we assume too much?

Given fundamental differences in the recommendations in guidelines from major national and international committees, we cannot rely on them unquestioningly. Different antihypertensive agents are known to have differing effects according to age and race. Exchanging (rather than following guideline recommendations of adding to) an ineffective first-line antihypertensive drug can result in control of hypertension with monotherapy. Conclusions about a preferable first-line antihypertensive agent are limited by trial protocols with varying drug doses and questionable drug combinations. Guidelines are often based on meta-analyses of drugs of a particular class, which could ignore important differences between drugs within a class. Trials of 3-5 years cannot determine the long-term effects of drugs which patients often take for decades.

Comparison of angiotensin-converting enzyme inhibitors in the treatment of congestive heart failure

The effectiveness of the different angiotensin-converting enzyme (ACE) inhibitors in the treatment of patients with congestive heart failure (CHF) was compared by performing a retrospective cohort study using linked administrative databases on elderly patients admitted to the hospital for the treatment of CHF. Relative to those initiated on enalapril, no significant differences in the combined end point of readmission to the hospital for CHF or mortality were observed among users of lisinopril, ramipril, or other ACE inhibitors. In terms of effectiveness for the treatment of patients with CHF, the findings of this study suggest a class effect among ACE inhibitors.

Angiotensin-Converting Enzyme Inhibitors and Stroke Risk: Benefit Beyond Blood Pressure Reduction?

Hypertension, a leading cause of morbidity and mortality, accounts for 25-49% of all strokes. Randomized placebo-controlled trials primarily with diuretics and beta-blockers administered in patients with hypertension have demonstrated a 38% reduction in primary stroke. Placebo-controlled trials with angiotensin-converting enzyme (ACE) inhibitors have not been conducted in patients with hypertension. However, in a meta-analysis of four placebo-controlled trials of ACE inhibitors in patients with coronary heart disease and/or diabetes mellitus, the overall risk of primary stroke was significantly reduced. Results of the Heart Outcomes Prevention Evaluation trial, which produced a substantial reduction in stroke with an apparently small reduction in blood pressure, suggest that the benefit of ACE inhibitors may be related to their effects on the renin-angiotensin-aldosterone system more than on blood pressure reduction. In active-control comparisons in patients with hypertension, ACE inhibitors have demonstrated reductions in primary stroke risk similar to reductions with diuretics, beta-blockers, and calcium channel blockers. The data suggest that for primary prevention of stroke antihypertensive therapy should be individualized in patients. Relatively few data are available concerning the benefit of antihypertensive therapy in the secondary prevention of stroke. In patients who had experienced a stroke or transient ischemic attack, therapy with a diuretic or a combination of a diuretic plus an ACE inhibitor could be recommended based on available outcome studies conducted in this patient population. It is premature to conclude that the benefit of ACE inhibitor therapy in primary or secondary prevention of stroke is an effect independent of blood pressure reduction. Hypertension detection, treatment, and control in patients still must be the principal focus of clinicians for both primary and secondary prevention of stroke.

Current trends in the cardiovascular clinical trial arena (I)

The existence of effective therapies for most cardiovascular disease states, coupled with increased requirements that potential benefits of new drugs be evaluated on clinical rather than surrogate endpoints, makes it increasingly difficult to substantiate any incremental improvements in efficacy that these new drugs might offer. Compounding the problem is the highly controversial issue of comparing new agents with placebos rather than active pharmaceuticals in drug efficacy trials. Despite the recent consensus that placebos may be used ethically in well-defined, justifiable circumstances, the problem persists, in part because of increased scrutiny by ethics committees but also because of considerable lingering disagreement regarding the propriety and scientific value of placebo-controlled trials (and trials of antihypertensive drugs in particular).The disagreement also substantially affects the most viable alternative to placebo-controlled trials: actively controlled equivalence/noninferiority trials. To a great extent, this situation was prompted by numerous previous trials of this type that were marked by fundamental methodological flaws and consequent false claims, inconsistencies, and potential harm to patients.As the development and use of generic drugs continue to escalate, along with concurrent pressure to control medical costs by substituting less-expensive therapies for established ones, any claim that a new drug, intervention, or therapy is "equivalent" to another should not be accepted without close scrutiny. Adherence to proper methods in conducting studies of equivalence will help investigators to avoid false claims and inconsistencies. These matters will be addressed in the third article of this three-part series.

Are cholesterol-lowering medications and antihypertensive agents preventing stroke in ways other than by controlling the risk factor?

Statins and angiotensin-converting enzyme (ACE) inhibitors are an important component of our armamentarium for stroke prevention. Both of these classes of agents have a primary mechanism of action of reducing the level of the respective risk factor. They also have mechanisms of action that may confer benefits beyond what is believed to be the primary action of the agent. This has led to speculation that statins reduce stroke risk by means beyond cholesterol lowering, and ACE inhibitors reduce stroke risk by means beyond blood pressure lowering. We review the mounting evidence that suggests that statins and ACE inhibitors have so-called pleiotropic effects that may lead to stroke prevention.

Are cholesterol-lowering medications and antihypertensive agents preventing stroke in ways other than by controlling the risk factor?

Statins and angiotensin-converting enzyme (ACE) inhibitors are an important component of our armamentarium for stroke prevention. Both of these classes of agents have a primary mechanism of action of reducing the level of the respective risk factor. They also have mechanisms of action that may confer benefits beyond what is believed to be the primary action of the agent. This has led to speculation that statins reduce stroke risk by means beyond cholesterol lowering, and ACE inhibitors reduce stroke risk by means beyond blood pressure lowering. We review the mounting evidence that suggests that statins and ACE inhibitors have so-called pleiotropic effects that may lead to stroke prevention.

Lack of therapeutic interchangeability of HMG-CoA reductase inhibitors

OBJECTIVE

To review relevant literature and provide an opinion on the class effect of hydroxymethylglutaryl coenzyme A reductase inhibitors (statins).

DATA SOURCES

Primary and review articles were identified by MEDLINE search (1990-July 2002).

STUDY SELECTION AND DATA EXTRACTION

Editorials, studies, and review articles related to the class effect or therapeutic interchangeability of statins were reviewed. Also included was information that is relevant to this topic.

DATA SYNTHESIS

Although statins share common main actions, they may have clinically important differences in terms of efficacy and safety. At fixed or allowable dosages, rosuvastatin, atorvastatin, and simvastatin produced greater low-density lipoprotein cholesterol-lowering effects compared with other statins. Some statins have shown reduction in either cardiovascular and/or total mortality. Statins also differ in their structure, pharmacokinetics, potency, and rate of metabolism, any or all of which may have clinical significance. Although inconclusive, subtle differences in nonlipid effects of some statins may have contributed to positive benefits observed in clinical studies. As a result of drug-related deaths, cerivastatin was withdrawn voluntarily from the market, which may raise the question whether there is therapeutic interchangeability (due to class effect) among statins.

CONCLUSIONS

Despite the competition for market share and strategies attempting to identify differences in therapeutic value, few head-to-head comparisons between statins have been performed. The limited, available data suggest that statins are not therapeutically interchangeable.

Mortality benefit of angiotensin-converting enzyme inhibitors after cardiac events in patients with end-stage renal disease

HYPOTHESIS/INTRODUCTION: The risks and benefits of angiotensin-converting enzyme (ACE) inhibitors in patients with end-stage renal disease (ESRD) after cardiac events are unknown. We sought to determine the independent effect of ACE inhibitors (ACE-I) on long-term mortality in ESRD patients after cardiac events.

MATERIALS AND METHODS

We analysed a prospective coronary care unit registry and identified 527 ESRD patients, 368 with complete data on medications prescribed, over eight years at a single, tertiary centre.

RESULTS

The overall mean age was 64.4+13.8 years with 54.9% men, and 59.2% African-American. A total of 143/386 (37.0%) were prescribed ACE-I during the hospital stay for cardiac reasons, including congestive heart failure (CHF) 52.8% and acute coronary syndromes (ACS) 47.2%. There were no significant differences in the rates of hypotension or arrhythmias in those who were treated with ACE-I versus those who were not. Survival analysis over three years, adjusted for known confounders, demonstrated a 37% reduction in all-cause mortality in those who received ACE-I, (p=0.0145).

CONCLUSIONS

In the setting of coronary care unit admission for CHF and ACS, ESRD patients selected for ACE-I, did not have increased rates of adverse haemodynamic or arrhythmic complications. The use of ACE-I conferred an independent mortality reduction over long-term follow-up.

Cost-effectiveness of hypertension treatment: a population-based study

CONTEXT

The cost-effectiveness of the treatment of hypertension has scarcely been investigated in population-based studies. Most data come from secondary analysis of clinical trials and administrative sources.

OBJECTIVE

To describe the health care costs for outpatient hypertension treatment in comparison with diabetes mellitus and chronic bronchitis, and to examine the cost-effectiveness of different classes of antihypertensive drugs.

DESIGN

Cross-sectional population-based study.

SETTING

Urban area of Pelotas, southern Brazil.

PARTICIPANTS

Individuals aged 20-69 years, identified through multi-stage probability sampling.

METHODS

Participants were interviewed at home. Demographic data, education, income, smoking, previous morbidity, use of medicine and other characteristics were assessed via a pre-tested questionnaire, and blood pressure while seated was measured in a standardized way.

RESULTS

Approximately 24% of the participants had high blood pressure or were taking antihypertensive drugs, and among these, 33% had had a physician consultation during the month preceding the interview. The monthly mean costs of care for hypertension (R$ 89.90), diabetes (R$ 80.64) and bronchitis (R$ 92.63) were similar. Treatment of hypertension consumed 22.9% of the per-capita income, corresponding to R$ 392.76 spent per year exclusively on antihypertensive drugs. Most of the direct costs associated with hypertension and diabetes were spent on drugs, while patients with bronchitis had greater expenditure on appointments. The cost-effectiveness relationship was more favorable for diuretics (116.3) and beta blockers (228.5) than for ACE inhibitors (608.5) or calcium channel blockers (762.0).

CONCLUSION

The costs of hypertension care are mainly dependent on the expenditure on blood pressure-lowering drugs. Treatment of hypertension with diuretics or beta blockers was more cost-effective than treatment with ACE inhibitors and calcium channel blockers.

Physicians' interpretation of "class effects": a need for thoughtful re-evaluation

The concept of pharmacologic "class effects" exists across a broad range of medical products and is particularly pervasive with regard to cardiovascular agents. Evolution of the concept over the past two decades has shown the influence of physicians' practice patterns, pharmaceutical companies, health maintenance organizations and the Food and Drug Administration (FDA). Understanding the evolution of health care, social and economic policies, acknowledging the correction of medical misconceptions and inaccurate understanding and appreciating the emergence of new medical knowledge over the past decade should modify the clinician's viewpoint of "class effects." These revelations should signal caution in extrapolating the outcome efficacy or safety of one agent to another within a pharmacologic class. The authors urge clinicians, pharmaceutical companies, health maintenance organizations and the FDA to re-examine their concept of "class effects." An appeal is made for physicians to prescribe those pharmaceutical agents with definitive evidence of mortality and morbidity efficacy and safety established by appropriately scaled randomized clinical trials.

New horizons for stroke prevention: PROGRESS and HOPE

Inhibitors of angiotensin-converting enzyme (ACE) act by blocking the conversion of angiotensin I to angiotensin II, which is catalysed by this enzyme. ACE inhibitors also prevent the breakdown of bradykinin, a potent vasodepressor agent, and prevent the effects of angiotensin II, which include increase in blood pressure, peripheral vasoconstriction, and stimulation of aldosterone secretion from the adrenal cortex. Physiological and pathological studies have shown that ACE inhibitors have beneficial effects, such as increasing vascular compliance, regression of periarteriolar collagen area, improvement of coronary reserve, and regression of resistance-artery structure and left-ventricular hypertrophy. Information about the role of ACE inhibitors in stroke prevention has been limited. This review explores the epidemiological evidence for hypertension as a risk factor for stroke, a national guideline for blood-pressure control to reduce the incidence of stroke and cardiovascular disease, the findings of two recently published clinical trials on prevention of stroke and cardiovascular disease after administration of ACE inhibitors (PROGRESS and HOPE), and the implications of the findings for redefinition of future management of blood-pressure control for individuals at high risk of stroke and cardiovascular disease. The PROGRESS and HOPE trials have shown that ACE inhibitors have an important role in the prevention of stroke and cardiovascular-disease events.