Effect of amlodipine on systolic blood pressure

Application of physiologically-based pharmacokinetic/pharmacodynamic models to evaluate the interaction between nifedipine and apatinib

Aim: It has been found that the co-administration of nifedipine with apatinib could cause exposure changes of nifedipine in vivo. But, whether this pharmacokinetic drug-drug interaction (DDI) between nifedipine and apatinib could enhance the antihypertensive effect of nifedipine, causing sever changes of blood pressure was unknown. Therefore, the aim of the present study was to conduct the pharmacokinetic/pharmacodynamic (PK/PD) modelling to evaluate the effect of pharmacokinetic changes on the antihypertensive effect of nifedipine. Thus, the results could guide the co-administration of these two drugs in clinic.

Methods: A physiologically-based pharmacokinetic (PBPK) model was first developed for nifedipine. The pharmacokinetic DDI between nifedipine and apatinib was evaluated. Then the verified PBPK models were linked to a PD model for investigating whether the exposure changes of nifedipine could cause severe changes in blood pressure. Furthermore, the changes in blood pressure caused by combination with apatinib were also assessed in patients with hepatic impairment via the PBPK/PD models.

Results: The predicted area under plasma concentration-time profile (AUC), maximum concentration (C_max), area under effect-time profile (AUE), and maximum reduction in systolic blood pressure (R_max) are all within 0.5–2.0-fold of the observed data, indicating that the PBPK/PD models for nifedipine are successfully established. The increases of predicted AUC and C_max of nifedipine in the presence of apatinib are 1.73 and 1.41-fold, respectively. Co-administration of nifedipine with apatinib could cause exposure changes of nifedipine in vivo. However, the predicted AUE and R_max changes of nifedipine in the presence to the absence of apatinib in cancer patients as well as in patients with hepatic impairment are all within 1.25-fold. The results indicate that the exposure changes of nifedipine caused by combination of apatinib has little effect on the changes of systolic blood pressure both in cancer patients and patients with hepatic impairment.

Conclusion: The pharmacokinetic changes of nifedipine caused by co-administration with apatinib has little impact on the antihypertensive effect of nifedipine. Apatinib is unlikely to cause severe pharmacodynamic DDI via inhibition of CYP3A4. It is suggested that nifedipine could be used in combination with apatinib without dose adjustment in clinic.

Ambulatory blood pressure response to S‐amlodipine in Korean adult patients with uncontrolled essential hypertension: A prospective, observational study

Although amlodipine is recommended as the first‐line therapy for the treatment of hypertension, its use is limited by its potential side effects. S‐amlodipine is expected to be able to minimize side effects of amlodipine with a similar antihypertensive effect by removing the malicious R‐chiral form. However, sustainable blood pressure control with S‐amlodipine has not been well established yet. The purpose of the current study was to evaluate ambulatory blood pressure (ABP) profiles before and after a 12‐week treatment of S‐amlodipine. Patients received once‐daily S‐amlodipine 2.5 or 5 mg. ABP during 24 hr and office blood pressure were measured at baseline and after the 12‐week treatment. Primary endpoints were changes of systolic and diastolic 24 hr ABP. After 12‐week S‐amlodipine treatment, mean systolic ABP (‐15.1 ± 16.2 mmHg, p < .001) and diastolic ABP (‐8.9 ± 9.8 mmHg, p < .001) were decreased significantly. Both daytime and night‐time mean systolic BP and diastolic BP were also significantly decreased after the 12‐week treatment. Global trough‐to‐peak ratio and smoothness index after 12‐week S‐amlodipine treatment were .75 and .79 for SBP and .65 and .61 for DBP, respectively. Age ≥65 years (hazard ratio [HR]: 3.13; 95% confidence interval [CI]: 1.67–14.3) and nonalcohol drinking (HR: 3.09; 95% CI: 1.34–7.17) were independent clinical factors for target ABP achievement. Adverse drug reactions (ADR) were developed in 16 (6.4%) patients, including two (.8%) cases of peripheral edema. In conclusion, this study demonstrated the efficacy and safety of S‐amlodipine in patients with uncontrolled essential hypertension.

Investigating the interaction between nifedipine- and ritonavir-containing antiviral regimens: A physiologically based pharmacokinetic/pharmacodynamic analysis

AIMS

Hypertension is a common comorbidity of patients with COVID-19, SARS or HIV infection. Such patients are often concomitantly treated with antiviral and antihypertensive agents, including ritonavir and nifedipine. Since ritonavir is a strong inhibitor of CYP3A and nifedipine is mainly metabolized via CYP3A, the combination of ritonavir and nifedipine can potentially cause drug-drug interactions. This study provides guidance on nifedipine treatment during and after coadministration with ritonavir-containing regimens, using a physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) analysis.

METHODS

The PBPK/PD models for 3 formations of nifedipine were developed based on the Simcyp nifedipine model and the models were verified using published data. The effects of ritonavir on nifedipine exposure and systolic blood pressure (SBP) were assessed for instant-release, sustained-release and controlled-release formulations in patients. Various nifedipine regimens were investigated when coadministered with or without ritonavir.

RESULTS

PBPK/PD models for 3 formulations of nifedipine were successfully established. The predicted maximum concentration (C_max ), area under plasma concentration-time curve (AUC), maximum reduction in SBP and area under effect-time curve were all within 0.5-2.0-fold of the observed data. Model simulations showed that the inhibitory effect of ritonavir on CYP3A4 increased the C_max of nifedipine 17.92-48.85-fold and the AUC 63.30-84.01-fold at steady state and decreased the SBP by >40 mmHg. Thus, the combination of nifedipine and ritonavir could lead to severe hypotension.

CONCLUSION

Ritonavir significantly affects the pharmacokinetics and antihypertensive effect of nifedipine. It is not recommended for patients to take nifedipine- and ritonavir-containing regimens simultaneously.

Guiding dose adjustment of amlodipine after co-administration with ritonavir containing regimens using a physiologically-based pharmacokinetic/pharmacodynamic model

Amlodipine, a commonly prescribed anti-hypertensive drug, shows increased systemic exposure with cytochrome P450 (CYP) 3A inhibitors. Ritonavir (RTV) is a potent mechanism-based and reversible CYP3A inhibitor and moderate inducer that is used as a pharmacokinetic enhancer in several antiviral treatment regimens. Drug-drug interaction (DDI) between RTV and amlodipine is due to mixed inhibition and induction of CYP3A4, which is challenging to predict without a mechanistic model that accounts for the complexity of both mechanisms occurring simultaneously. A novel physiologically-based pharmacokinetic (PBPK) model was developed for amlodipine, and the model was verified using published clinical PK and DDI data. The verified amlodipine PBPK model was linked to a pharmacodynamics model that describes changes in systolic blood pressure (SBP) during and after co-administration with RTV. The magnitude and time course of RTV effects on amlodipine plasma exposures and SBP were evaluated, to provide guidance on dose adjustment of amlodipine during and after co-administration with RTV-containing regimens. Model simulations suggested that the increase in amlodipine's plasma exposure by RTV diminishes by approximately 80% within 5 days after the last dose of RTV. PBPK simulations suggested that resuming a full dose of amlodipine [5 mg once daily (QD)] immediately after RTV's last dose would decrease daily average SBP by a maximum of 3.3 mmHg, while continuing with the reduced dose (2.5 mg QD) for 5 days after the last dose of RTV would increase daily average SBP by a maximum of 5.8 mmHg. Based on these results, either approach of resuming amlodipine's full dose could be appropriate when combined with appropriate clinical monitoring.

Comparison of Monotherapy with Irbesartan 150 mg or Amlodipine 5 mg for Treatment of Mild-to-Moderate Hypertension

Objective. The primary objective of this study was to compare the antihypertensive efficacy of the angiotensin II receptor blocker irbesartan 150 mg and the calcium channel blocker amlodipine 5 mg in the treatment of patients with seated diastolic blood pressure (DBP) 95—110 mmHg.

Design. Multicentre, randomised, double-blind, comparative pilot study.

Methods. Subjects were 18—65 years of age, with DBP 95—110 mmHg, and of non-African American origin. Following a three-week, single-blind, placebo lead-in period, 181 subjects were randomised in a 1:1 ratio to receive once-daily irbesartan 150 mg (n=89) or amlodipine 5 mg (n=92) for four weeks. Trough (24±3 hours post-dosing) BP measurements were obtained at baseline and at Weeks 2 and 4 under standardised, controlled conditions. Response was defined as DBP <90 mmHg or a reductionfrom baseline of ≥10 mmHg.

Results. After four weeks of treatment, the mean (±SE) decrease from baseline in DBP was 9.4±0.6 mmHg in the irbesartan group vs. 9.6±0.6 mmHg in the amlodipine group (p=0.806). The mean decrease from baseline in seated systolic BP was 12.2±1.0 mmHg in the irbesartan group vs. 12.0±1.0 mmHg in the amlodipine group (p=0.885). Overall, 62% of subjects in the irbesartan group and 63% in the amlodipine group had a response (p=0.609), and 54% and 56% of patients (p=0.596), respectively, had their DBP normalised (<90 mmHg). Adverse events were reported by 21.3% of patients receiving irbesartan and 20.7% receiving amlodipine.

Conclusions. Irbesartan 150 mg demonstrated comparable efficacy to amlodipine 5 mg, thereby confirming its value as an antihypertensive treatment option in non-African American patients with DBP 95—110 mmHg.

Therapeutic potential of chalcones as cardiovascular agents

Cardiovascular diseases are the leading cause of death affecting 17.3 million people across the globe and are estimated to affect 23.3 million people by year 2030. In recent years, about 7.3 million people died due to coronary heart disease, 9.4 million deaths due to high blood pressure and 6.2 million due to stroke, where obesity and atherosclerotic progression remain the chief pathological factors. The search for newer and better cardiovascular agents is the foremost need to manage cardiac patient population across the world. Several natural and (semi) synthetic chalcones deserve the credit of being potential candidates to inhibit various cardiovascular, hematological and anti-obesity targets like angiotensin converting enzyme (ACE), cholesteryl ester transfer protein (CETP), diacylglycerol acyltransferase (DGAT), acyl-coenzyme A: cholesterol acyltransferase (ACAT), pancreatic lipase (PL), lipoprotein lipase (LPL), calcium (Ca(2+))/potassium (K(+)) channel, COX-1, TXA2 and TXB2. In this review, a comprehensive study of chalcones, their therapeutic targets, structure activity relationships (SARs), mechanisms of actions (MOAs) have been discussed. Chemically diverse chalcone scaffolds, their derivatives including structural manipulation of both aryl rings, replacement with heteroaryl scaffold(s) and hybridization through conjugation with other pharmacologically active scaffold have been highlighted. Chalcones which showed promising activity and have a well-defined MOAs, SARs must be considered as prototype for the design and development of potential anti-hypertensive, anti-anginal, anti-arrhythmic and cardioprotective agents. With the knowledge of these molecular targets, structural insights and SARs, this review may be helpful for (medicinal) chemists to design more potent, safe, selective and cost effective chalcone derivatives as potential cardiovascular agents.

Knowledge, Awareness and Self-Care Practices of Hypertension Among Cardiac Hypertensive Patients

Introduction:

The most prevalent form of hypertension is systolic blood pressure (SBP) and it is considered to be predisposing risk factor for cardiovascular disease. The objective of the study was to assess self-care practices, knowledge and awareness of hypertension, especially related to SBP among cardiac hypertensive patients.

Methodology:

A Cross sectional study was conducted on 664 cardiac hypertensive patients, which were selected by non-probability convenience sampling from cardiology outpatient department of three tertiary care hospitals. Face to face interviews were conducted using a pre designed questionnaire. Data was entered and analyzed by SPSS (V17).

Results:

81.8%, did not know that hypertension is defined as high blood pressure. 97.1% of the sample population did not know that top measurement of blood pressure was referred to as systolic and only 25.0% correctly recognized normal systolic blood pressure to be less than 140mmHg. 7.4% of the patients consulted their doctor for hypertension once or twice in a month. Risk factor for high blood pressure most commonly identified by the participants was too much salt intake

Conclusions:

The results state that there is an inadequate general knowledge of hypertension among cardiac patients and they do not recognise the significance of elevated SBP levels. There is a need to initiate programs that create community awareness regarding long term complications of uncontrolled hypertension, particularly elevated SBP levels so that there is an improvement in self-care practices of the cardiacpatients.

Combination therapy in the extended cardiovascular continuum: a focus on perindopril and amlodipine

The progression of cardiovascular disease could be regarded as following atherosclerosis-related and age-related pathways. The starting points for these pathways are different--risk factors or aortic ageing--but they conclude in the same way: end-stage heart disease. Together these interlinked pathways form the extended cardiovascular continuum. Renin-angiotensin-aldosterone system (RAAS) inhibitors have been shown to interrupt or slow the progression of cardiovascular disease along one pathway, the cardiovascular atherosclerotic continuum. Cardiovascular protection with RAAS inhibitors varies; different RAAS inhibitors offer different levels of protection. Similarly, calcium channel blockers (CCBs) also have clearly shown protective effect of cardiovascular system, especially as it regards cerebrovascular disease risk. The AngloScandinavian Cardiac Outcomes Trial (ASCOT) showed that a combination of the angiotensin-converting enzyme (ACE) inhibitor perindopril and CCB amlodipine offered better cardiovascular protection in at-risk hypertensive patients than beta-blocker and thiazide. By attenuating the deleterious effects of cardiovascular disease at multiple stages of the extended cardiovascular continuum on top of lowering blood pressure (BP), perindopril and amlodipine could interrupt and slow the progression of cardiovascular disease. These antihypertensive agents have complementary vascular effects that enhance cardiovascular protection and reduce side-effects. Evidence from ASCOT shows that antihypertensive and vascular effects of amlodipine with and without perindopril have translated into real-life clinical benefits. A strategy using ACE inhibitors and CCBs, such as perindopril and amlodipine, to target multiple stages in both pathways of cardiovascular disease could effectively reduce cardiovascular risk and lower BP.

[Orally active aminopeptidase A inhibitors reduce blood pressure: a new strategy for treating hypertension]

The hyperactivity of the brain renin-angiotensin system (RAS) has been implicated in the development and maintenance of hypertension in several types of experimental and genetic hypertension animal models. Among the main bioactive peptides of the brain RAS, angiotensin (Ang) II and Ang III display the same affinity for type 1 and type 2 Ang II receptors. Both peptides, injected intracerebroventricularly, similarly increase arginine vasopressin release and blood pressure (BP); however, because Ang II is converted in vivo to Ang III, the identity of the true effector is unknown. We first identified the enzymes involved in the metabolism of brain angiotensins and developed specific and selective inhibitors. Here we review new insights into the predominant role of brain Ang III in the control of BP, underlining the fact that brain aminopeptidase A (APA), the enzyme generating brain Ang III, may therefore be an interesting candidate target for the treatment of hypertension. This justifies the development of potent systemically active APA inhibitors, such as RB150, as prototypes of a new class of antihypertensive agents for the treatment of certain forms of hypertension.

A new strategy for treating hypertension by blocking the activity of the brain renin-angiotensin system with aminopeptidase A inhibitors

Hypertension affects one-third of the adult population and is a growing problem due to the increasing incidence of obesity and diabetes. Brain RAS (renin-angiotensin system) hyperactivity has been implicated in the development and maintenance of hypertension in several types of experimental and genetic hypertension animal models. We have identified in the brain RAS that APA (aminopeptidase A) and APN (aminopeptidase N), two membrane-bound zinc metalloproteases, are involved in the metabolism of AngII (angiotensin II) and AngIII (angiotensin III) respectively. The present review summarizes the main findings suggesting that AngIII plays a predominant role in the brain RAS in the control of BP (blood pressure). We first explored the organization of the APA active site by site-directed mutagenesis and molecular modelling. The development and the use in vivo of specific and selective APA and APN inhibitors EC33 and PC18 respectively, has allowed the demonstration that brain AngIII generated by APA is one of the main effector peptides of the brain RAS, exerting a tonic stimulatory control over BP in conscious hypertensive rats. This identified brain APA as a potential therapeutic target for the treatment of hypertension, which has led to the development of potent orally active APA inhibitors, such as RB150. RB150 administered orally in hypertensive DOCA (deoxycorticosteroneacetate)-salt rats or SHRs (spontaneously hypertensive rats) crosses the intestinal, hepatic and blood-brain barriers, enters the brain, generates two active molecules of EC33 which inhibit brain APA activity, block the formation of brain AngIII and normalize BP for several hours. The decrease in BP involves two different mechanisms: a decrease in vasopressin release into the bloodstream, which in turn increases diuresis resulting in a blood volume reduction that participates in the decrease in BP and/or a decrease in sympathetic tone, decreasing vascular resistance. RB150 constitutes the prototype of a new class of centrally acting antihypertensive agents and is currently being evaluated in a Phase Ib clinical trial.

Tolerability and effectiveness of (S)-amlodipine compared with racemic amlodipine in hypertension: a systematic review and meta-analysis

BACKGROUND

Amlodipine is a calcium channel blocker prescribed for the management of angina and hypertension. As a racemic mixture, amlodipine contains (R)- and (S)-amlodipine isomers, but only (S)-amlodipine as the active moiety possesses therapeutic activity. Based on pharmacologic research, it remains uncertain if (S)-amlodipine alone has similar efficacy and fewer associated adverse events (AEs) compared with the racemic mixtures.

OBJECTIVE

The aim of this systematic review and meta-analysis was to determine the effectiveness and tolerability of (S)-amlodipine compared with that of racemic amlodipine.

METHODS

A systematic literature search was performed using MEDLINE (1966-2009), EMBASE (1966-2009), the Cochrane Central Register of Controlled Trials (issue 3, 2009), the Chinese Biomedical Database (1978-2009), and the China National Knowledge Internet (1980-2009). All randomized controlled trials (RCTs) comparing (S)-amlodipine 2.5 mg and racemic amlodipine 5.0 mg in the treatment of hypertension were included in the review. The outcome measures to be collected were cardiovascular events, systolic blood pressure (SBP), diastolic BP (DBP), and AEs. Quality assessments of clinical trials were conducted using a modified Jadad Scale, with trials being rated as low quality (score 0-3) or high quality (score 4-7). Meta-analysis of the included studies was performed using RevMan software.

RESULTS

Of the 229 references identified, 214 were excluded after screening the titles, abstracts, or full texts. Fifteen RCTs were included, of which 13 were in Chinese and 2 in English. Based on the Jadad Scale score, 3 of the RCTs were classified as high quality (score 5 or 6) and the remaining 12 as low quality (score 1-3). None of the trials evaluated cardiovascular events beyond 40 weeks. Meta-analysis of the 15 trials indicated that (S)-amlodipine was not significantly different from racemic amlodipine in the effect on BP. When only high-quality studies were included, after 4 weeks' treatment, the weighted mean difference (WMD) of SBP and DBP decrease (1 study) was -2.84 (95% CI, -6.42 to 0.74) with (S)-amlodipine and -1.71 (95% CI, -3.48 to 0.06) with racemic amlodipine. After 8 weeks' treatment, the WMD of SBP and DBP decrease (2 studies) was -1.13 (95% CI, -5.29 to 3.03) and -1.34 (95% CI, -2.67 to -0.01), respectively. The risk difference (RD) for the number of patients who experienced AEs with (S)-amlodipine and racemic amlodipine was found to be -0.04 (95% CI, -0.06 to -0.02). When all the trials were included, (S)-amlodipine treatment was associated with significantly less edema than racemic amlodipine (RD, -0.02; 95% CI, -0.03 to 0.00); however, when only high-quality studies (2 studies) were included, no difference was found between the 2 groups (RD, 0.01; 95% CI, -0.02 to 0.03). One high-quality study found significant differences in increases in aspartate and alanine aminotransferase activities in the 2 groups (RD, 0.08; 95% CI, 0.01 to 0.05). No significant differences between the 2 groups were found in the incidence of headache (RD, 0.00; 95% CI, -0.02 to 0.01) or flushing (RD, -0.01; 95% CI, -0.02 to 0.00).

CONCLUSIONS

The majority of the clinical trials comparing (S)-amlodipine and racemic amlodipine treatment were low quality (12/15 [80%]). According to the limited evidence, there were no significant differences between (S)-amlodipine 2.5 mg and racemic amlodipine 5.0 mg in controlling BP. When all the trials were considered, (S)-amlodipine treatment was associated with significantly less edema than racemic amlodipine; however, when only high-quality trials were included, no significant difference was found. More long-term, high-quality RCTs with cardiovascular events as the primary outcome are needed to compare the safety and efficacy of (S)-amlodipine and racemic amlodipine.

The role of the brain renin-angiotensin system in hypertension: implications for new treatment

Hypertension affects 26% of adults and is in constant progress related to increased incidence of obesity and diabetes. One-third of hypertensive patients may be successfully treated with one antihypertensive agent, one-third may require two agents and in the remaining patients will need three agents for effective blood pressure (BP) control. The development of new classes of antihypertensive agents with different mechanisms of action therefore remains an important goal. Brain renin-angiotensin system (RAS) hyperactivity has been implicated in hypertension development and maintenance in several types of experimental and genetic hypertension animal models. Among the main bioactive peptides of the brain RAS, angiotensin (Ang) II and Ang III have similar affinities for type 1 (AT1) and type 2 (AT2) Ang II receptors. Following intracerebroventricular (i.c.v.) injection, Ang II and Ang III similarly increase arginine-vasopressin (AVP) release and BP. Blocking the brain RAS may be advantageous as it simultaneously (1) decreases sympathetic tone and consequently vascular resistance, (2) decreases AVP release, reducing blood volume and vascular resistance and (3) blocks angiotensin-induced baroreflex inhibition, decreasing both vascular resistance and cardiac output. However, as Ang II is converted to Ang III in vivo, the exact nature of the active peptide is not precisely determined. We summarize here the main findings identifying AngIII as one of the major effector peptides of the brain RAS in the control of AVP release and BP. Brain AngIII exerts a tonic stimulatory effect on BP in hypertensive rats, identifying brain aminopeptidase A (APA), the enzyme generating brain Ang III, as a potentially candidate target for hypertension treatment. This has led to the development of potent orally active APA inhibitors, such as RB150--the prototype of a new class of centrally acting antihypertensive agents.

Combination therapy in hypertension: A focus on angiotensin receptor blockers and calcium channel blockers

Every third adult in the United States has hypertension. Hypertension is a continuous, independent, potent risk factor for cardiovascular events like stroke, myocardial infarction, and heart failure. The blood pressure control achieved with most hypertensives is way below the recommended goal. Recent trials suggest that for nearly half of hypertensive patients, a monotherapy regimen is not adequate to control blood pressure. Investigators recommend from randomized, controlled studies that combination therapy be considered when blood pressure is above the goal of 20/10 mm Hg. In this review we discuss clinical trials that establish the need for combination therapy, with the primary focus on a new combination: calcium channel blockers (CCBs) and angiotensin receptor blockers (ARBs). ARBs and CCBs in combination can complement each other in lowering blood pressure, with a lower incidence of adverse effects, as compared with individual monotherapy components at high doses.

[Combined antihypertensive and antilipemic therapy as one of the pillars in the poly-pharmacologic preventive strategy for patients with high cardiovascular risk]

Hypertension is a highly prevalent disease and a strong risk factor for cardiovascular disease in industrialized countries in Europe and North America. About 40-50% of hypertensive patients have some other cardiovascular risk factors as smoking, dyslipidemia, glucose intolerance, metabolic syndrome and diabetes. The realization of optimal therapy of these patients is a difficult task, and reaching target blood pressure values is almost impossible by monotherapy. It was realized that the simultaneous normalization of blood pressure and that of abnormal lipid profile with 2-3 or more drugs have great importance for preventing atherosclerotic complications.We started an open-formed study with about 1000 hypertensive patients complicated with dyslipidemia, visceral obesity, metabolic syndrome and diabetes type 2. The base of our therapeutic strategy was a typical poly-pharmacologic treatment with ACE inhibitor (lisinopril), calcium antagonist (amlodipine), statin (atorvastatin) and antiplatelet therapy (if it was necessary).

Single-pill amlodipine/atorvastatin helps patients of diverse ethnicity attain recommended goals for blood pressure and lipids (the Gemini-AALA study)

The Gemini-AALA (Australia, Asia, Latin America, Africa/Middle East) study evaluated the efficacy and safety of single-pill amlodipine/atorvastatin (Caduet) for the treatment of patients of diverse ethnicity with concomitant hypertension and dyslipidaemia. This was a 14-week, open-label study including patients from 27 countries across the Middle East, Asia-Pacific, Africa and Latin America. Eight dosage strengths of single-pill amlodipine/atorvastatin (5/10, 10/10, 5/20, 10/20, 5/40, 10/40, 5/80 and 10/80 mg) were titrated to improve blood pressure and lipid control. Blood pressure and lipid goals were determined according to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) and National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (NCEP ATP III) guidelines, respectively (blood pressure, <140/90 or <130/80 mm Hg; low-density lipoprotein cholesterol (LDL-C), <4.1 to <2.6 mmol l(-1) (<160 to <100 mgdl(-1))). Overall, 1649 patients received study medication. Most patients (91.4%) had >or=1 cardiovascular risk factor (as defined by NCEP ATP III guidelines) in addition to hypertension/dyslipidaemia, and 61.7% had coronary heart disease/risk equivalent. At baseline, mean blood pressure was 146.6/88.3 mm Hg and LDL-C was 3.4 mmol l(-1) (130.2 mgdl(-1)). At week 14, 55.2% of patients reached both blood pressure and lipid goals, 61.3% reached blood pressure goal and 87.1% reached lipid goal (34.0% were at lipid goal at baseline). Mean blood pressure reduction was 20.2/11.4 mm Hg. For patients who were lipid-lowering drug naive at baseline, mean reduction in LDL-C was 41.0%. Treatment-related adverse events led to the discontinuation of 3.6% of patients. Single-pill amlodipine/atorvastatin therapy was well tolerated and effective for the reduction of blood pressure and lipids to recommended goals in patients from diverse ethnic backgrounds.

Jacques Benoit lecture: the neuroendocrine view of the angiotensin and apelin systems

The hyperactivity of the brain renin-angiotensin system (RAS) has been implicated in the development and maintenance of hypertension in several types of experimental and genetic hypertension animal models. Among the main bioactive peptides of the brain RAS, angiotensin (Ang) II and Ang III display the same affinity for type 1 and type 2 Ang II receptors. Both peptides, injected intracerebroventricularly, similarly increase arginine vasopressin (AVP) release and blood pressure (BP); however, because Ang II is converted in vivo to Ang III, the identity of the true effector is unknown. We review new insights into the predominant role of brain Ang III in the control of BP, underlining the fact that brain aminopeptidase A (APA), the enzyme generating brain Ang III, may therefore be an interesting candidate target for the treatment of hypertension. This justifies the development of potent systemically active APA inhibitors, such as RB150, as prototypes of a new class of antihypertensive agents for the treatment of certain forms of hypertension. We also searched for a putative angiotensin receptor subtype specific for Ang III and isolated a seven transmembrane-domain G protein-coupled receptor corresponding to the receptor for apelin, a newly-discovered peptide isolated from bovine stomach. Apelin and its receptor are expressed in magnocellular vasopressinergic neurones in the hypothalamus. The central injection of apelin in lactating rats decreases the phasic electrical activity of vasopressinergic neurones and the systemic secretion of AVP, inducing water diuresis. Apelin is therefore a natural inhibitor of the antidiuretic effect of AVP. In addition, systemic administration of apelin decreases BP, improves cardiac contractility and reduces cardiac loading. The development of nonpeptide agonists of the apelin receptor may provide new therapeutic tools for treating water retention, hyponatraemia and cardiovascular diseases. Angiotensins and apelin thus exert opposing but complementary effects, and are thereby determinant for the maintenance of body fluid homeostasis and cardiovascular functions.

Modulation of arterial reactivity using amlodipine and atorvastatin measured by ultrasound examination (MARGAUX)

OBJECTIVE

To evaluate the effect of the calcium channel blocker amlodipine on endothelial function in normotensive patients with coronary disease taking concomitant atorvastatin therapy.

METHODS AND RESULTS

Atorvastatin was titrated (10-80 mg/day) to maintain LDL-C<2.5 mmol/L and patients were randomized to receive amlodipine (5-10mg/day, n=64) or placebo (n=70) for 12 months. Brachial artery flow-mediated vasodilation (FMD) was assessed using vascular ultrasound. Inflammatory markers were also measured. At 12 months there was a significant decrease in mean low-density lipoprotein cholesterol (LDL-C) (4.4-2.1 mmol/L, P<0.0001), high-sensitivity C-reactive protein (hsCRP) (3.8-2.3mg/L, P<0.0001) and soluble vascular cell adhesion molecule-1 (sVCAM-1) (710-665 ng/mL, P<0.0001) for all patients, compared with baseline. Amlodipine was associated with a mean blood pressure reduction of 8/3 mm Hg (P<0.0001) whereas patients on placebo had no significant change. In the atorvastatin-placebo group, mean FMD increased (7.3-9.5%, P<0.05) with no change in nitroglycerin-mediated dilation. No further benefit on FMD or inflammatory markers was observed with the addition of amlodipine.

CONCLUSIONS

Intensive reduction of LDL-C with atorvastatin improves endothelium-dependent vasodilation and reduces markers of inflammation in patients with coronary disease. Amlodipine was not associated with a significant additional benefit on these variables.

Aminopeptidase A inhibitors as centrally acting antihypertensive agents

Among the main bioactive peptides of the brain renin-angiotensin system, angiotensin (Ang) II and AngIII exhibit the same affinity for the type 1 and type 2 Ang receptors. Both peptides, injected intracerebroventricularly, cause similar increase in blood pressure (BP). Because AngII is converted in vivo to AngIII, the identity of the true effector is unknown. This review summarized recent insights into the predominant role of brain AngIII in the central control of BP underlining the fact that brain aminopeptidase A (APA), the enzyme forming central AngIII, could constitute a putative central therapeutic target for the treatment of hypertension. This led to the development of potent, systematically active APA inhibitors, such as RB150, as a prototype of a new class of centrally acting antihypertensive agents for the treatment of certain forms of hypertension.

Estimating the proportion of young adults on antihypertensive treatment that have been correctly diagnosed

This paper aims to identify how many young adults on antihypertensive treatment have been misclassified as hypertensive. We identified subjects aged under 35 on antihypertensive treatment, from the Health Surveys for England, 1998-2004. Pretreatment systolic and diastolic blood pressures were calculated by adjusting on-treatment blood pressures for the effects of treatment. Treatment effects were derived from meta-analysis. Subjects were classified as hypertensive if pretreatment blood pressure was >or=160/100 mm Hg, or was >or=140/90 mm Hg in conjunction with high cardiovascular risk. We then identified the proportion of treated subjects on antihypertensive treatment who were truly eligible for treatment. From the survey data we identified 65 adults (25 men and 40 women) under 35 on diuretics, beta-blockers, angiotensin converting enzyme inhibitors, calcium blockers or other antihypertensives. Average pretreatment blood pressure was 164/100 mm Hg in those eligible for treatment, and 136/79 mm Hg in those not eligible. The analysis indicated that 29.2% of adults aged 16-34 (95% confidence interval (CI): 18.6-41.8%) were truly eligible for antihypertensive treatment: 32.0% (95% CI: 14.9-53.5%) of men and 25.0% (95% CI: 12.7-41.2%) of women. A total of 73.7% (14 of 19) of subjects eligible and 41.3% (19 of 46) of subjects not eligible for treatment either had a body mass index >30 kg m(-2) or kidney disease (chi(2)-test P=0.018). Because of biological variation in blood pressure, most young adults on treatment for hypertension have been misclassified as hypertensive. Most who have been correctly diagnosed are either clinically obese or have kidney disease.

Simultaneous treatment of hypertension and dyslipidaemia may help to reduce overall cardiovascular risk: focus on amlodipine/atorvastatin single-pill therapy

Single-pill amlodipine besylate/atorvastatin calcium (Caduet), Pfizer Inc, NY, USA) is the first therapy aimed at the simultaneous treatment of hypertension (HTN) and dyslipidaemia (DYS). The benefits of lowering blood pressure (BP) in patients with HTN and lowering cholesterol in patients with DYS are well known and well studied. However, worldwide, many patients with HTN have concomitant DYS, which places them at greater risk for cardiovascular disease compared with patients with just one of these risk factors. Clinical trials have demonstrated that amlodipine plus atorvastatin can be safely co-administered across the dose range. Single-pill amlodipine/atorvastatin reduces both BP and cholesterol and may help to improve the management of patients with concomitant HTN and DYS.

Brain renin-angiotensin system blockade by systemically active aminopeptidase A inhibitors: a potential treatment of salt-dependent hypertension

The hyperactivity of the brain renin-angiotensin system (RAS) has been implicated in the development and maintenance of hypertension in several types of experimental and genetic hypertension animal models. We previously reported that in the murine brain, aminopeptidase A (APA) is involved in the conversion of angiotensin II (AngII) to AngIII and that AngIII is one of the main effector peptides of the brain RAS in the control of vasopressin release. Here we report that brain AngIII exerts a tonic stimulatory effect on blood pressure in a model of salt-dependent hypertension, the DOCA-salt rat, characterized by a depressed systemic but a hyperactive brain RAS. Similar high blood pressure accompanied by a low systemic renin state was described in some patients, especially in hypertensive African Americans who are resistant to treatment by blockers of the systemic RAS. We developed RB150, a prodrug of the specific and selective APA inhibitor, EC33. RB150 given i.v. is able to cross the blood-brain barrier, to inhibit brain APA, and to block the formation of central AngIII. A single dose of systemic RB150 (15 mg/kg, i.v.) in conscious DOCA-salt rats inhibited brain APA activity and markedly reduced blood pressure for up to 24 h. These results demonstrate the crucial role of brain APA as a candidate target for the treatment of hypertension and suggest that RB150, a potent systemically active APA inhibitor, could be the prototype of a new class of antihypertensive agents for the treatment of certain forms of hypertension.

Hypertension and the elderly: more than just blood pressure control

Hypertension is a major risk factor for cardiovascular disease in both young and elderly persons; therefore, good blood pressure control is at the center of improved cardiovascular health. The recently issued seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure and the European Society of Hypertension/European Society of Cardiology 2003 guidelines for hypertension management emphasize the importance of treatment efficacy rather than age in treating elderly persons with hypertension. Most hypertension clinical trials have been carried out with younger hypertensives, but this is changing with trials such as the Systolic Hypertension in the Elderly Program, the first Swedish Trial of Old Patients With Hypertension, and the Systolic Hypertension in Europe trial. These trials have clearly demonstrated the benefits of good blood pressure control in reducing the risk of stroke in elderly persons. With many safe and effective antihypertensive drugs on the market, the question becomes how elderly persons should be treated. Elderly patients often have isolated systolic hypertension, which is related to loss of arterial elasticity or compliance with aging and is more recalcitrant to treatment than essential hypertension. In addition, with advancing age there is the likelihood that other disease states are present in addition to hypertension. The newer antihypertensive drugs that interfere with the renin angiotensin system, such as angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers, have the potential of improving cardiovascular outcomes in elderly persons in addition to offering effective blood pressure reduction. Their use should be considered within a comprehensive risk assessment that includes individualized risk-benefit considerations.