AMLODIPINE, A LONG-ACTING CALCIUM CHANNEL BLOCKER, ATTENUATES MORNING BLOOD PRESSURE RISE IN HYPERTENSIVE PATIENTS

1. The effects of once-daily calcium channel blockers with different plasma half-lives on diurnal blood pressure changes were examined in hypertensive patients. 2. Patients with essential hypertension, nine men and 13 women aged 61 +/- 2 years, were treated with amlodipine or nitrendipine in a random cross-over design for 12-16 weeks each. The study drugs were given once daily as monotherapy (n = 8) or in combination with other classes of antihypertensive drugs (n = 14). The plasma half-life of amlodipine is as long as 36 h, while that of nitrendipine is 10 h. At the end of each treatment period, 24 h ambulatory blood pressure and pulse rate were monitored. 3. Average office blood pressure was comparably controlled below 140/90 mmHg by either amlodipine or nitrendipine, both in the monotherapy and the combination therapy groups; however, pulse rate was greater in nitrendipine than in amlodipine either in the monotherapy (by 6 b.p.m., P < 0.05) or in the combination therapy (by 5 b.p.m., P < 0.01). 4. In 24 h blood pressure monitoring, morning (05.30-09.00 h) blood pressure was higher in nitrendipine than in amlodipine by 6/4 mmHg in the monotherapy (P < 0.05) and by 7/5 mmHg in the combination therapy (P < 0.03), although the blood pressure in the remainder of the 24 h did not differ between the two treatment periods. In addition, pulse rate in the daytime (09.30-18.00 h) was greater in nitrendipine than in amlodipine by 6 b.p.m. in the monotherapy (P < 0.01) and by 7 b.p.m. in the combination therapy (P < 0.02). 5. These results suggest slow pharmacokinetics of amlodipine provides an advantage in controlling morning blood pressure and mitigating reflex activation of the sympathetic nervous system.     

Efficacy and Tolerability of Amlodipine in the General Practice Treatment of Essential Hypertension in an Asian Multinational Population

OBJECTIVE: To evaluate the efficacy and tolerability of once-daily amlodipine (Pfizer Pharmaceuticals Inc.) alone or in combination with other antihypertensive drugs in an Asian population with essential hypertension. PATIENTS: An open study was undertaken in 165 male and 158 female patients with uncomplicated hypertension (diastolic blood pressure 95 to 115mm Hg). Patients were recruited from 41 general practices in seven Asian countries and received amlodipine 5mg daily for 4 weeks and then 10mg once daily for a further 4 weeks if the target diastolic blood pressure of /=10mm Hg had not been achieved. This one-step dose-adjustment period was followed by a 4-week maintenance period on a constant dose. Amlodipine was the sole medication in 284 patients and was added to other antihypertensive drugs in 39 patients uncontrolled on previous medication. RESULTS: 263 patients, including 131 males, were evaluated for efficacy at the final treatment visit. 166 (63%) patients achieved the target reduction in diastolic blood pressure with amlodipine 5mg once daily, while 84 patients achieved the target reduction with 10mg once daily. Systolic and diastolic blood pressure reductions were similar irrespective of gender or age, and there were no significant changes in resting heart rate in any subgroup. In 68 patients who underwent ambulatory monitoring, the systolic and diastolic blood pressures were reduced by once-daily amlodipine throughout the 24-hour period without change in the intrinsic circadian pattern. Amlodipine was well tolerated in all patient subgroups; adverse events accounted for less than 1% of treatment discontinuations, and there were no hospitalisations or deaths during the study. Investigators rated both the antihypertensive efficacy and tolerability of amlodipine as excellent or good in 93% of patients. CONCLUSION: In 263 Asian patients with uncomplicated essential hypertension treated in general practice, once-daily amlodipine in a dose of 5 or 10mg provided significant antihypertensive efficacy either as monotherapy or in combination with other antihypertensive drugs while maintaining a favourable tolerability profile regardless of gender or age.     

Comparison of the Efficacy and Safety of Fixed-Dose Amlodipine/Losartan and Losartan in Hypertensive Patients Inadequately Controlled with Losartan

Background

Fixed-dose combination drugs may enhance blood pressure (BP) goal attainment through complementary effects and reduced side effects, which leads to better compliance.

Objective

This study aimed to evaluate the efficacy and safety profiles of once-daily combination amlodipine/losartan versus losartan.

Methods

This was an 8-week, double-blind, multicenter, randomized phase III study conducted in outpatient hospital clinics. Korean patients with essential hypertension inadequately controlled on losartan 100 mg were administered amlodipine/losartan 5 mg/100 mg combination versus losartan 100 mg. The main outcome measures were changes in sitting diastolic blood pressure (DBP) and sitting systolic blood pressure (SBP) and BP response rate from baseline values, which were assessed after 4 and 8 weeks of treatment. Safety and tolerability were also assessed.

Results

At week 8, both groups achieved significant reductions from baseline in DBP (11.7 ± 7.0 and 3.2 ±7.9 mmHg), which was significantly greater in the amlodipine/losartan 5 mg/100 mg combination (n = 70) group (p < 0.0001). Additionally, the amlodipine/losartan 5 mg/100 mg combination group achieved significantly greater reductions in SBP at week 8 and in SBP and DBP at week 4 compared with the losartan 100 mg (n = 72) group (all p<0.0001). Response rates were significantly higher in the amlodipine/losartan 5 mg/100 mg group versus the losartan 100 mg group (81.4% vs 63.9% at week 4, p < 0.0192; 90.0% vs 66.7% at week 8, p<0.001). Both treatments were generally well tolerated.

Conclusion

Switching to a fixed-dose combination therapy of amlodipine/losartan 5 mg/100 mg was associated with significantly greater reductions in BP and superior achievement of BP goals compared with a maintenance dose of losartan 100 mg in Korean patients with essential hypertension inadequately controlled on losartan 100 mg.

Clinical Trial Registration

Registered at Clinicaltrials.gov as NCT00940680.     

Efficacy and tolerability of candesartan cilexetil/hydrochlorothiazide and amlodipine in patients with poorly controlled mild-to-moderate essential hypertension.

The antihypertensive efficacy and tolerability of combination therapy with candesartan cilexetil, 16 mg plus hydrochlorothiazide (CC/HCTZ), 12.5 mg was compared with that of amlodipine, in a multicentre, double-blind, randomised, parallel-group study in patients with mild-to-moderate essential hypertension inadequately controlled by monotherapy. After a two week run-in period on existing therapy, patients with a sitting diastolic blood pressure (DBP) of 90-110 mmHg and a sitting systolic blood pressure (SBP) 相似文献   

Blood Pressure Effects of High-Dose Amlodipine-Benazepril Combination in Black and White Hypertensive Patients Not Controlled on Monotherapy

Background

Black hypertensive patients are more resistant to angiotensin-converting enzyme (ACE) inhibitor monotherapy than White patients. This resistance can be overcome with the combination of ACE inhibitors with diuretics or calcium-channel blockers (CCBs).

Objectives

The objective of this clinical investigation was to evaluate the antihypertensive effectiveness of monotherapy with the ACE inhibitor benazepril or the CCB amlodipine and their combination in Black and White hypertensive patients in two separate studies.

Methods

This was a post hoc analysis of data from two separate studies, pooled because of their similarities, to increase the sample size. Outpatient Black and White hypertensive patients were selected for these studies. In study H2303, 201 patients of both sexes and races, whose mean seated diastolic blood pressure (MSDBP) was ≥95 mmHg after 4 weeks of single-blind treatment with benazepril 40mg/day, were randomized into two groups. Group 1 received benazepril 40mg/day and group 2 received amlodipine/benazepril 5/40mg/day, which was uptitrated to amlodipine/benazepril 10/40 mg/day at week 4 of the study. In study H2304, 812 similar patients, whose MSDBP was ≥95 mmHg after 4 weeks of single-blind treatment with amlodipine 10 mg/day, were randomized into three groups. Group 1 received amlodipine/benazepril 10/20 mg/day, uptitrated to amlodipine/benazepril 10/40 mg/day after 2 weeks. Group 2 received amlodipine/benazepril 10/20 mg/day. Group 3 received amlodipine 10 mg/day. All three groups were followed up for 6 additional weeks.

Results

This report presents the results of post hoc analysis of pooled data from two separate but similar studies. Combination therapy resulted in greater lowering of MSDBP and mean seated systolic blood pressure (MSSBP) than monotherapy with either benazepril or amlodipine (p< 0.001). With respect to combination therapy, the combination of amlodipine/benazepril 10/20 mg/day resulted in greater blood pressure (BP) reductions in White patients than in Black patients (p<0.004). In contrast, the combination of amlodipine/benazepril 10/40 mg/day resulted in similar BP reductions in both Black and White hypertensive patients. There were no serious clinical or metabolic side effects noted, with the exception of pedal edema, which was more common with amlodipine monotherapy.

Conclusion

This study showed that combination therapy with amlodipine/benazepril is more effective in BP lowering than monotherapy with the component drugs. Black hypertensive patients are responsive to the combination of amlodipine/benazepril; however, they require higher dose combinations for BP reductions similar to those achieved in White hypertensive patients.     

Additive beneficial effects of amlodipine and atorvastatin in reversing advanced cardiac hypertrophy in elderly spontaneously hypertensive rats

• 1 Additive beneficial effects on cardiovascular disease have been reported for amlodipine and atorvastatin. However, it is still unclear whether the combination of amlodipine and atorvastatin has additive beneficial effects on the regression of advanced cardiac hypertrophy in hypertension. In the present study, the effects of the drug combination on advanced cardiac hypertrophy were investigated in elderly spontaneously hypertensive rats (SHR).
• 2 Elderly SHR (36 weeks old) were randomly allocated into four groups of 12: (i) a vehicle‐treated control group; (ii) an amlodipine (10 mg/kg per day)‐treated group; (iii) an atorvastatin (10 mg/kg per day)‐treated group; and (iv) a group treated with a combination of amlodipine and atorvastatin (both at 10 mg/kg per day). Drugs were administered by oral gavage every morning for a period of 12 weeks before hearts were harvested for analysis.
• 3 Combined administration of amlodipine and atorvastatin significantly suppressed cardiomyocyte hypertrophy, interstitial fibrosis and upregulation of hypertrophic and profibrotic genes, and also improved left ventricular diastolic dysfunction to a greater extent than did amlodipine monotherapy. Further beneficial effects of combination therapy on advanced cardiac hypertrophy were associated with a greater reduction of NADPH oxidase‐mediated increases in cardiac reactive oxygen species (ROS), rather than decreased blood pressure and serum cholesterol levels.
• 4 To elucidate the underlying molecular mechanisms, we examined cardiovascular NADPH oxidase subunits and found that amlodipine clearly attenuated the expression of p47^phox and p40^phox and slightly but significantly reduced p22^phox and Rac‐1 levels in heart tissue. Combination treatment with amlodipine plus atorvastatin led to a further reduction in p22^phox, p47^phox and Rac‐1 protein levels compared with amlodipine alone.
• 5 In conclusion, combined amlodipine and atorvastatin treatment has a greater beneficial effect on advanced cardiac hypertrophy compared with amlodipine monotherapy. The benefits are likely to be related to the additive effects of the drugs on the suppression of NADPH oxidase‐mediated ROS generation.

     

Fixed-dose combination enalapril/nitrendipine: a review of its use in mild-to-moderate hypertension

The fixed-dose combination of enalapril 10mg with nitrendipine 20mg combines an ACE inhibitor with a calcium channel antagonist (CCA) and is indicated for the treatment of patients with mild-to-moderate hypertension whose blood pressure (BP) is inadequately controlled with enalapril or nitrendipine monotherapy. In randomised, double-blind clinical trials, enalapril/nitrendipine 10/20 mg/day was significantly more effective than its individual components in reducing diastolic BP (DBP) in patients with mild-to-moderate hypertension inadequately controlled with enalapril 10 mg/day or nitrendipine 20 mg/day. The fixed-dose combination was similar in efficacy at reducing DBP to amlodipine 10 mg/day in patients who failed to achieve BP control with amlodipine 5 mg/day, and to losartan/hydrochlorothiazide 50/12.5 mg/day in patients who received the combinations as first-line therapy. Enalapril/nitrendipine 10/20 mg produced a consistent antihypertensive effect that persisted for the entire 24-hour dosage interval as shown by ambulatory BP monitoring. Enalapril/nitrendipine 10/20 mg was well tolerated in clinical trials where it was administered to patients with mild-to-moderate hypertension for up to 12 weeks. The adverse events were those expected of ACE inhibitors and CCAs and included cough, headache and flushing. Evidence from clinical trials, including a pooled analysis, suggests that the incidence of oedema may be significantly lower with the fixed-dose combination than with CCA monotherapy.In conclusion, enalapril/nitrendipine 10/20 mg is a well tolerated fixed-dose combination of two established antihypertensive agents administered once daily that effectively lowers BP throughout the 24-hour dosage interval. Importantly, the fixed-dose combination may have a lower incidence of oedema than CCA monotherapy. Enalapril/nitrendipine 10/20 mg provides an additional treatment option for patients with mild-to-moderate hypertension for whom combination therapy is appropriate.     

Losartan and prevention of atrial fibrillation recurrence in hypertensive patients

The aim of the study was to evaluate the effect of losartan as compared with amlodipine, both associated with amiodarone, in preventing the recurrence of atrial fibrillation (AF) in hypertensive patients with a history of recent paroxysmal atrial fibrillation. Two hundred and fifty mild hypertensive (SBP > 140 mm Hg and/or DBP > 90 < 100 mm Hg) outpatients in sinus rhythm but with at least two ECG-documented episodes of symptomatic atrial fibrillation in the previous 6 months and in treatment with amiodarone were randomized to losartan or amlodipine and were followed up for 1 year. Clinic blood pressure (BP) and a 24-hour ECG was evaluated every month; the patients were asked to report any episode of symptomatic atrial fibrillation and to perform an ECG as early as possible. Two hundred and thirteen patients completed the study, 107 in the losartan group and 106 in the amlodipine group. After 12 months the SBP/DBP mean values were significantly reduced by both losartan (from 151.4/95.6 to 135.5/83.7 mm Hg, P < 0.001 versus baseline) and amlodipine (from 152.3/96.5 to 135.2/83.4 mm Hg, P < 0.001 versus baseline), with no difference between the two treatments. At least one ECG-documented episode of atrial fibrillation was reported in 13% of the patients treated with losartan and in 39% of the patients treated with amlodipine. The use of losartan in combination with amiodarone seems more effective than amlodipine/amiodarone combination in preventing new episodes of atrial fibrillation in hypertensive patients with recurrent atrial fibrillation. This might be related to possible favorable impact of angiotensin II receptor blockers (ARB) on the atrial electrical and structural remodeling in this type of patients.     

Effects of nine antihypertensive drugs on blood pressure variability in sinoaortic-denervated rats

AIM: The present work was designed to investigate the effects of nine commonly used antihypertensive drugs on blood pressure (BP) and blood pressure variability (BPV) in conscious sinoaortic-denervated (SAD) rats. METHODS: Seventy-two SAD rats were randomly divided into nine groups. They were respectively given nifedipine 3 mg/kg, nitrendipine 5 mg/kg, amlodipine 1 mg/kg, clonidine 10 mug/kg, prazosin 0.5 mg/kg, atenolol 20 mg/kg, telmisartan 20 mg/kg, hydrochlorothiazide 40 mg/kg or captopril 50 mg/kg. The drugs were given via a catheter previously implanted into the stomach. BP was recorded for 5 h from 1 h before drug administration to 4 h after drug administration in conscious, freely moving rats. RESULTS: It was found that all these nine drugs significantly decreased BP in SAD rats. Six of these drugs (nifedipine, nitrendipine, amlodipine, clonidine, prazosin and atenolol) significantly decreased BPV in SAD rats, but the remaining three drugs did not. Clonidine and atenolol increased the heart period and the others did not. No drugs affected the heart period variability. CONCLUSION: Among nine antihypertensive drugs from different classes, calcium antagonists and sympathetic inhibitors decreased BPV in SAD rats.     

氯沙坦与氨氯地平的降压疗效及对左室肥厚逆转作用的比较

目的 :评价并比较氯沙坦及氨氯地平的降压疗效及对左室肥厚的逆转作用。方法 :12 0例高血压病伴左室肥厚病人随机分为 2组。氯沙坦组6 0例 ,给氯沙坦 2 5～ 50mg ,po ,qm。氨氯地平组6 0例 ,给氨氯地平 5～ 10mg ,po ,qm ;疗程均为 2 4wk。结果 :治疗 2 4wk后 ,氯沙坦组SBP和DBP下降差值分别为 (3.4± 1.7)kPa和 (2 .7± 0 .7)kPa ,氨氯地平组为 (3.2± 1.5)kPa和 (2 .2± 0 .9)kPa(均P<0 .0 1)。组间比较 ,氯沙坦组除偶测血压SBP外 ,DBP和 2 4h动态血压均较氨氯地平组下降显著 (P<0 .0 1)。2组室间隔厚度、左心室后壁厚度、左室心肌重量指数较治疗前显著改善 (P <0 .0 1)。结论 :氯沙坦与氨氯地平均能显著降压 ,并使左室肥厚逆转     

Beneficial effects of the combination of nifedipine and losartan in hypertensive Dahl salt-sensitive rats

BACKGROUND: The antihypertensive and organ-protective effects of the combination of the angiotensin II type 1 receptor blocker losartan and the calcium channel blocker nifedipine were examined in Dahl salt-sensitive rats. METHODS: The rats fed with a high-salt diet developed hypertension accompanied by aorta and heart hypertrophy, and impaired renal function. The animals were treated with losartan (30 mg/kg/day), nifedipine (7.8 mg/kg/day) or with a combination of both drugs for 8 weeks. At the end of the study systolic blood pressure, kidney function, organ weight, and mRNA expression were investigated. RESULTS: Losartan reduced significantly the systolic blood pressure as well as the aorta and left ventricular hypertrophy. Nifedipine and its combination with losartan had similar effects on the systolic blood pressure, aorta and left ventricular hypertrophy but only the combination treatment reduced the expression of transforming growth factor-beta1 in aorta and brain natriuretic peptide in left ventricle significantly. Nifedipine and the combination therapy reduced proteinuria and improved urine creatinine excretion. The expression of collagen III and IV in the kidney was significantly reduced by the combination therapy. CONCLUSION: These results indicate that although losartan and nifedipine were effective in lowering blood pressure and showed moderate organ protection, additional benefits can be expected by combination therapy with both compounds.     

Candesartan cilexetil plus hydrochlorothiazide combination: a review of its use in hypertension

The combination of candesartan cilexetil [an angiotensin II type 1 (AT(1)) receptor antagonist] plus hydrochlorothiazide (a thiazide diuretic), has been used in the treatment of patients with hypertension. The blood pressure (BP) lowering effect of various doses of this combination, administered orally once a day for 4 to 52 weeks, has been demonstrated in clinical trials. These studies showed that combinations of candesartan cilexetil 4 to 16 mg with hydrochlorothiazide 12.5 or 25 mg induced significant reductions reductions in systolic (S) BP and diastolic (D) BP from baseline in patients with mild to severe hypertension. Data from clinical trials indicated that reductions in BP induced by candesartan cilexetil 4 to 32 mg/hydrochlorothiazide 12.5 mg combinations were significantly greater than those observed after monotherapy with either drug. Treatment for 8 weeks with candesartan cilexetil 16 mg/hydrochlorothiazide 12.5 mg or candesartan cilexetil 16 mg induced SBP/DBP reductions of 12.0/7.5 mm Hg and 7.5/5.5mm Hg, respectively (p < 0.05 both comparisons). Moreover, data from a randomised, double-blind, placebo-controlled, dose-finding study in 1038 patients with mild to moderate hypertension showed that the greatest reductions in SBP/DBP were achieved by candesartan cilexetil 16 mg/hydrochlorothiazide 12.5 mg. Significant differences in BP reduction in favour of the combination were observed when hypertensive patients were given candesartan cilexetil 4 or 8 mg/hydrochlorothiazide 12.5 mg or hydrochlorothiazide monotherapy for 8 weeks. Additionally, greater efficacy of the combination compared to monotherapy with either drug was demonstrated by response rates to treatment. Moreover, a fixed combination of candesartan cilexetil 16 mg/hydrochlorothiazide 12.5 mg demonstrated a greater antihypertensive effect than losartan 50 mg/hydrochlorothiazide 12.5 mg in two clinical trials. Candesartan cilexetil 8 mg/hydrochlorothiazide 12.5 mg showed a similar antihypertensive effect compared with that of combined lisinopril 10 mg/hydrochlorothiazide 12.5 mg. Candesartan cilexetil/hydrochlorothiazide combination was well tolerated in patients with hypertension. Combined data from placebo-controlled trials showed that most adverse events were uncommon and not serious. Patients receiving combination therapy exhibited, among other adverse events, headache (3.2 vs 5.5% for candesartan cilexetil/hydrochlorothiazide and placebo, respectively), back pain (3.0 vs 2.4%), dizziness (2.6 vs 1.2%) and respiratory infection (2.5 vs 1.4%). Moreover, 3.3 and 2.7% of patients receiving candesartan cilexetil/hydrochlorothiazide or placebo, respectively, discontinued treatment because of adverse events. CONCLUSION: The combination of candesartan cilexetil and hydrochlorothiazide (AT(1)-receptor antagonist and thiazide diuretic, respectively) is an effective treatment for patients with hypertension. Data from randomised, double-blind, placebo-controlled clinical trials showed that this combination is significantly more efficacious than either agent alone. Moreover, the combination of these two agents showed an excellent adverse event profile. Current data support the use of this combination as an alternative when monotherapy with either agent is not effective, and there are no compelling or specific indications for other drugs. However, data from large clinical trials, evaluating morbidity and mortality outcomes, are needed to determine the precise role of candesartan cilexetil/hydrochlorothiazide combination in the treatment of patients with hypertension.     

A Meta-Analytical Approach to the Efficacy of Antihypertensive Drugs in Reducing Blood Pressure

INTRODUCTION: Hypertension constitutes a veritable public health issue. Several classes of drugs are available for the treatment of hypertension. The objective of this meta-analytical approach was to assess the efficacy of antihypertensive drugs most commonly used in France in reducing clinical SBP and DBP. METHODS: The antihypertensive drugs selected were hydrochlorothiazide, indapamide sustained release (SR), furosemide and spironolactone for diuretics; amlodipine and lercanidipine for calcium channel antagonists; atenolol for beta-adrenoceptor antagonists (beta-blockers); enalapril and ramipril for ACE inhibitors; and candesartan cilexetil, irbesartan, losartan, and valsartan for angiotensin II receptor antagonists. The trials selected were published between 1973 and 2004, evaluated monotherapy with trial drugs as fixed-dosage or with dosage increase, and assessed blood pressure reduction between 2 and 3 months. The analysis method used was based on the calculation of the sum weighted for the trial size. RESULTS: A total of 72 trials (comprising 9094 patients) were selected and analyzed. No trial evaluating furosemide or spironolactone satisfied the inclusion criteria for this analysis. For SBP, the reduction was more marked with diuretics, calcium channel antagonists, and ACE inhibitors. Of all the drugs studied, indapamide SR gave the greatest SBP reduction (-22.2 mm Hg). Evaluated therapeutic classes had a similar magnitude of effect on DBP, i.e. reduction between -11.4 mm Hg with beta-adrenoceptor antagonists and -10.3 mm Hg with angiotensin II type 1 receptor antagonists. CONCLUSION: Indapamide SR 1.5 mg appeared to be the most effective drug for a significant reduction in SBP within 2-3 months, which is an essential element in optimizing cardiovascular prevention among hypertensive patients. The clinical application of these results should take into consideration all the limitations discussed in this analysis.     

Comparison of vasculoprotective effects of benidipine and losartan in a rat model of metabolic syndrome

Although antihypertensive drugs confer improvement in endothelial dysfunction and protection from atherogenesis in hypertension, different classes of antihypertensive drugs may elicit different degrees of vasculoprotective effects. We have investigated the effects of a long-acting calcium antagonist, benidipine, and an angiotensin AT(1) receptor antagonist, losartan, on the vascular damage observed in OLETF rats, an animal model of metabolic syndrome. At 34 weeks of age, OLETF rats were treated with either benidipine (3 mg/kg/day, per os) or losartan (25 mg/kg/day, per os) for 8 weeks. The extent of blood pressure reduction, restoration endothelium-dependent aortic relaxation, and elevation of serum nitrite/nitrate concentration did not differ significantly between benidipine- and losartan-treated OLETF rats. Benidipine and losartan also reduced the aortic expression of transforming growth factor-beta1 mRNA and thickening of the vascular wall to a similar extent. Increased cardiac fibrosis was also inhibited by both benidipine and losartan. These data suggest that, when used in an antihypertensive dose, benidipine is as effective as losartan in restoring vascular endothelial function and in suppressing of cardiovascular remodeling in an animal model of metabolic syndrome.     

Bisoprolol/amlodipine combination therapy improves blood pressure control in patients with essential hypertension following monotherapy failure

Objective: The efficacy of a bisoprolol/amlodipine fixed-dose combination (FDC) in patients with essential hypertension who had not responded to bisoprolol or amlodipine monotherapy was investigated.

Research design and methods: In an 18 week, multicenter, randomized, comparative phase III study (ClinicalTrials.gov identifier: NCT01977794), patients with blood pressure uncontrolled by bisoprolol or amlodipine monotherapy (5?mg OD) began treatment with bisoprolol/amlodipine FDC 5/5?mg OD. Patients with controlled blood pressure (BP) at week 6/12 continued at current FDC strength, and patients with uncontrolled BP received FDC dose uptitration (maximum dose: 10/10?mg). The primary efficacy endpoint was change in systolic blood pressure (SBP) at week 18 versus baseline (corresponding to SBP under monotherapy), and secondary endpoints included change from baseline in SBP after week 6/12 and percentage of BP-controlled patients at week 6, 12 and 18. Safety was assessed by number/types of adverse events (AEs).

Results: Two hundred patients were randomized to treatment (100 with uncontrolled BP under bisoprolol and 100 under amlodipine monotherapy). Overall, 196 patients were eligible for analysis. The patient groups displayed similar mean SBP reductions from baseline by study end (bisoprolol monotherapy failure: 25.9?±?12.82?mmHg reduction; amlodipine monotherapy failure: 24.7?±?11.67?mmHg reduction; p?<?0.001 for both). Overall mean SBP decreased by 25.3?±?12.25?mmHg (p?<?0.001). Mean heart rate reductions were also observed (bisoprolol monotherapy failure: 6.6?±?9.67 bpm reduction; amlodipine monotherapy failure: 11.5?±?8.65 bpm reduction; p?<?0.001 for both). Most patients (83.2%) displayed BP control with bisoprolol/amlodipine 5/5?mg at 6 weeks. Treatment was well tolerated at all dose levels; treatment-related AEs (mostly of mild/moderate intensity) were reported by 52.5% of patients, with no severe or serious treatment-related AEs reported. As the study focused on hypertension, total cardiovascular risk was not assessed.

Conclusions: Bisoprolol/amlodipine FDC therapy is associated with significant BP improvements in patients with essential hypertension following monotherapy failure.     

Clinical effectiveness of low-dose chlorthalidone (6.25 mg) + atenolol combination in stage I hypertensive patients: a multicenter,randomized, controlled study

ABSTRACT

Objective: To compare the efficacy and safety of low-dose chlorthalidone + atenolol combination with atenolol and atenolol + amlodipine combination in stage I hypertensive patients uncontrolled on active run-in monotherapy.

Methods: Newly diagnosed stage I hypertensive patients were randomized to active run-in monotherapy either with atenolol 25?mg (98/300) or chlorthalidone 6.25?mg (100/300) or amlodipine 2.5?mg (102/300). A total of 282/300 patients (atenolol 92, chlorthalidone 91, amlodipine 99) completed the active run-in phase successfully. Patients uncontrolled on active run-in monotherapy (atenolol 33, chlorthalidone 45, amlodipine 47) received the study treatment, namely atenolol 50?mg alone, chlorthalidone 6.25?mg + atenolol 25?mg and atenolol 25?mg + amlodipine 2.5?mg, respectively. Efficacy of the therapy was evaluated by BP measurement at weeks 12 and 20 post-therapy.

Results: Post-active run-in monotherapies, the study treatment groups showed a significant fall in mean SBP and DBP from baseline (p?<?0.05). The mean fall in SBP and DBP was comparable for study treatments (atenolol 50?mg, atenolol 25?mg + chlorthalidone 6.25?mg and atenolol 25?mg + amlodipine 2.5?mg) (p = 0.337 for SBP and p = 0.054 for DBP) at week 12 and (p = 0.744 for SBP and p = 0.855 for DBP) at week 20; also, the percentage of responders was comparable for the three study treatment groups (p = 0.799) indicating that the low-dose chlorthalidone + atenolol combination is non-inferior to the high-dose atenolol alone and atenolol + amlodipine combination. No serious laboratory/clinical adverse events were reported in this study.

Conclusion: Chlorthalidone 6.25?mg in combination with atenolol 25?mg is effective and safe in stage I (JNC 7) essential hypertensive patients. This low dose of chlorthalidone could reduce dose-related concerns over metabolic adverse effects and may lead to wider usage of this proven antihypertensive agent in combination therapy.     

Telmisartan: a review of its use in hypertension

Telmisartan is an angiotensin II receptor antagonist that is highly selective for type 1 angiotensin II receptors. It was significantly more effective than placebo in large (n >100), double-blind, randomised, multicentre clinical trials in patients with mild to moderate hypertension. Telmisartan 20 to 160 mg once daily produced mean reductions in supine trough systolic blood pressure and diastolic blood pressure of up to 15.5 and 10.5 mm Hg, respectively. Maximum blood pressure reduction occurred with a dosage of 40 to 80 mg/day. Telmisartan 40 to 120 mg/day was as effective as amlodipine 5 to 10 mg/day or atenolol 50 to 100 mg/day in dose-titration studies. Telmisartan 20 to 160 mg/day was generally similar in efficacy to enalapril 5 to 20 mg/day or lisinopril 10 to 40 mg/day in both titration-to-response and other studies. Hydrochlorothiazide was coadministered in most of the titration-to-response studies if patients remained hypertensive. Telmisartan 80 mg/day was more effective than submaximal dosages of losartan (50 mg/day) or valsartan (80 mg/day) and was as effective as a fixed-dose combination of losartan 50 mg plus hydrochlorothiazide 12.5 mg over the last 6 hours of the dosage interval and the whole 24-hour postdose interval. In patients with severe hypertension, telmisartan 80 to 160 mg/day was as effective as enalapril 20 to 40 mg/day (both agents could be titrated and combined sequentially with hydrochlorothiazide 25 mg and amlodipine 5 mg). The addition of hydrochlorothiazide to telmisartan was more effective than each agent alone at lowering blood pressure in patients with hypertension. Telmisartan was well tolerated in patients with mild to moderate hypertension and was significantly less likely to cause persistent, dry cough than lisinopril. Conclusion: Telmisartan is an effective antihypertensive agent with a tolerability profile similar to that of placebo. Comparative data have shown telmisartan to be as effective as other major classes of antihypertensive agents at lowering blood pressure. Compared with lisinopril, telmisartan is associated with a significantly lower incidence of dry, persistent cough. Therefore, telmisartan is a useful therapeutic option in the management of patients with hypertension.     

Two useful methods for evaluating antihypertensive drugs in conscious freely moving rats

INTRODUCTION Since the beginning of 1980s, a computerized tech-nique has been developed for measuring blood pressure(BP) for a long time (more than 24 h) in consciousfreely moving rats[1-5]. With this technique one can studythe cardiaovascular parameters in a physiological con-dition in rats and avoid the influences of anesthesia andstress. This technique is used not only for physiologicalstudies but also for pharmacological studies including theevaluationof antihypertensive drugs.…     

Effects of combination therapy with atenolol and amlodipine on blood pressure control and stroke prevention in stroke-prone spontaneously hypertensive rats

Aim： To test the effects of atenolol and amlodipine, either alone or in combination, on blood pressure, blood pressure variability （BPV）, baroreflex sensitivity （BRS）, and the prevalence of stroke in stroke-prone spontaneously hypertensive rats （SHR-SP）. Methods： In the first set of the study, 24 8-month-old, female SHR-SP rats were randomly divided into 3 groups. Blood pressure, heart period, and BRS were determined before and after the intragastric administration of atenolol （10 mg/kg） and amlodipine （1.0 mg/kg）, either alone or in combination. In the second set of the study, 40 male and 40 female rats were randomly assigned to 1 of the following 4 groups： control, atenolol （10 mg·kg^-1·d^-1）, amlodipine （1.0 mg·kg^-1·d^-1）, and both （10 male and 10 female in each group）. The stroke incident and survival time were recorded. Results： Atenolol and amlodipine, either alone or in combination, significantly decreased blood pressure, with the exception of the amlodipine-induced effect on diastolic blood pressure. Meanwhile, only the combination treatment significantly decreased the BPV levels for the same period. The q-values calculated by the probability sum analysis were 1.17 and 2.67 for systolic and diastolic blood pressure, respectively, and were 2.48 and 2.10 for systolic and diastolic BPV, respectively, following administration. Neither drug exhibited any significant effect on BRS. Atenolol and amlodipine, either alone or in combination, significantly increased the lifespan of SHR-SP, with the best effect elicited by the combination therapy. Conclusion： A significant synergism exists between atenolol and amlodipine in lowering and stabilizing blood pressure in SHR-SP. Combination therapy may be an optimal strategy for the prevention of stroke in hypertension.     

Evaluation of the Dose-Response Relationship of Amlodipine and Losartan Combination in Patients with Essential Hypertension

Background

Despite recommendations for more intensive treatment and the availability of several effective treatments, hypertension remains uncontrolled in many patients.

Objective

The aim of this study was to determine the dose-response relationship and assess the efficacy and safety of amlodipine or losartan monotherapy and amlodipine camsylate/losartan combination therapy in patients with essential hypertension.

Methods

This was an 8-week, randomized, double-blind, factorial design, phase II, multicenter study conducted in outpatient hospital clinics among adult patients aged 18?C75 years with essential hypertension. At screening, patients received placebo for 2?C4 weeks. Eligible patients (n = 320) were randomized to one of eight treatment groups: amlodipine 5 mg or 10 mg, losartan 50 mg or 100 mg, amlodipine camsylate/losartan 5mg/50mg, 5mg/100mg, 10mg/50mg, or 10mg/100mg.

Main Outcome Measures

The assumption of strict superiority was estimated using the mean change in sitting diastolic blood pressure (DBP) at 8 weeks. Safety was monitored through physical examinations, vital signs, laboratory test results, ECG, and adverse events.

Results

The reduction in DBP at 8 weeks was significantly greater in patients treated with the combination therapies compared with the respective monotherapies for all specified comparisons except amlodipine camsylate/losartan 10mg/100mg versus amlodipine 10mg. The incidence of adverse events in the group of patients treated with the amlodipine camsylate/losartan 10mg/50mg combination tended to be higher than for any other group (27.9%, 12/43); however, the effect was not statistically significant.

Conclusion

Combination amlodipine camsylate/losartan (5mg/50mg, 5mg/100mg and 10mg/50mg) resulted in significantly greater BP lowering compared with amlodipine or losartan monotherapy, and was determined to be generally safe and tolerable in patients with essential hypertension.

Clinical Trial Registration

Registered at clinicaltrials.gov: NCT00942344.