Comparison of amlodipine and benazepril monotherapy to amlodipine plus benazepril in patients with systemic hypertension: a randomized, double-blind, placebo-controlled, parallel-group study. The Benazepril/Amlodipine Study Group

Comparative peripheral edema for dihydropyridines calcium channel blockers treatment: A systematic review and network meta-analysis

Dihydropyridine calcium channel blockers (DHPCCBs) are widely used to treat hypertension and chronic coronary artery disease. One common adverse effect of DHPCCBs is peripheral edema, particularly of the lower limbs. The side effect could lead to dose reduction or discontinuation of the medication. The combination of DHPCCBs and renin-angiotensin system blockers has shown to reduce the risk of DHPCCBs-associated peripheral edema compared with DHPCCBs monotherapy. We performed the current systematic review and network meta-analysis of randomized controlled trials (RCTs) to estimate the rate of peripheral edema with DHPCCBs as a class and with individual DHPCCBs and the ranking of the reduction of peripheral edema. The effects of renin-angiotensin system blockers on DHPCCBs network meta-analysis were created to analyze the ranking of the reduction of peripheral edema. A total of 3312 publications were identified and 71 studies with 56,283 patients were included. Nifedipine ranked highest in inducing peripheral edema (SUCRA 81.8%) and lacidipine (SUCRA 12.8%) ranked the least. All DHPCCBs except lacidipine resulted in higher relative risk (RR) of peripheral edema compared with placebo. Nifedipine plus angiotensin receptor blocker (SUCRA: 92.3%) did not mitigate peripheral edema and amlodipine plus angiotensin-converting enzyme inhibitors (SUCRA: 16%) reduced peripheral edema the most. Nifedipine ranked the highest and lacidipine ranked the lowest amongst DHPCCBs for developing peripheral edema when used for cardiovascular indications. The second or higher generation of DHPCCBs combination with ACEIs or ARBs or diuretics lowered the chance of peripheral edema development compared to single DHPCCB treatment.

Combination Antihypertensive Therapy Prescribing and Blood Pressure Control in a Real-World Setting

BACKGROUND

Specific combinations of two drug classes are recommended in a variety of clinical situations in the management of hypertension. These preferred combinations are based on complimentary blood pressure (BP) lowering mechanisms or benefit for a concomitant disease.

METHODS

Using electronic health records (EHRs) data from 27,579 ambulatory hypertensive patients, we investigated antihypertensive therapy prescribing patterns and associations of preferred two drug classes with BP control.

RESULTS

Overall, BP control, defined as BP <140/90 mm Hg, was 65% among treated patients. Preferred dual antihypertensive therapy was prescribed in 55% of patients with uncomplicated hypertension, 49% of patients with diabetes, and 47% of patients with a history of myocardial infarction (MI); these prescribing frequencies of preferred combinations were not explained by worse BP control on those combinations. In fact, we found suggestive evidence of association between prescribing of preferred two drug classes and improved BP control among post-MI (OR: 1.21, 95% CI: 0.99-1.48, P = 0.061) and uncomplicated hypertensive (OR: 1.11, 95% CI: 0.98-1.26, P = 0.089) patients.

CONCLUSIONS

Prescribing of guideline-recommended antihypertensive drug classes for concomitant diseases is suboptimal and prescribing of preferred/optimized drug class combinations was moderate. We did not find a clear association between the use of optimized drug class combinations and greater BP control. Overall, using EHR data, we identified potential opportunities for re-examining prescribing practices with implications for clinical decision support and healthcare improvement at the community and health system-wide levels.

Effects of combining azilsartan medoxomil with amlodipine in patients with stage 2 hypertension

Objective

The aim of the study was to measure the effects on blood pressure (BP) of the angiotensin receptor blocker azilsartan medoxomil, in 40 and 80 mg doses, combined with 5 mg of the calcium channel blocker amlodipine and to compare these effects with placebo plus amlodipine 5 mg.

Methods

This was a randomized, controlled, double-blind study of 6 weeks’ duration in 566 patients with stage 2 hypertension. The primary endpoint was 24-h systolic BP by ambulatory monitoring.

Results

The mean age of the participants was 58 years; men and women were equally represented, and baseline 24-h BP (153–154/93 mmHg) and clinic BP (165–166/94–95 mmHg) were similar across the three treatment groups. After 6 weeks, 24-h BP decreased by 25/15 mmHg in both the azilsartan medoxomil/amlodipine 40/5 and 80/5 mg groups. These reductions were each greater than the 14/8 mmHg decrease with placebo plus amlodipine 5 mg (P≤0.001 for both comparisons). All treatments were well tolerated, and adverse events did not increase with the azilsartan medoxomil doses. Edema or fluid retention was less common in both combination groups (2.6 and 2.7%) than with placebo plus amlodipine (7.6%).

Conclusion

Coadministration of azilsartan medoxomil with amlodipine was well tolerated and led to meaningful additional BP reductions compared with placebo plus amlodipine.

The efficacy and safety of fixed-dose combination of amlodipine/benazepril in Chinese essential hypertensive patients not adequately controlled with benazepril monotherapy: a multicenter, randomized, double-blind, double-dummy, parallel-group clinical trial

This double-blind, double-dummy clinical trial evaluated the efficacy and safety of two strengths of fixed-dose combination of amlodipine/benazepril in Chinese hypertensive patients not adequately controlled with benazepril. Of 442 patients who received treatment with benazepril 10 mg for 4 weeks, 341 patients failed to achieve to diastolic blood pressure (DBP) <90 mmHg. These non-responders were randomized to receive amlodipine/benazepril 2.5/10 mg, or amlodipine/benazepril 5/10 mg, or benazepril 10 mg for 8 weeks. BP reductions with amodipinel/benazepril 2.5/10 mg (15.2/11.8 mmHg) or amlodipine/benazepril 5/10 mg (15.4/12.4 mmHg) were significantly greater than that with benazepril 10 mg (9.88/9.46 mmHg) at study end (p < 0.01, combination versus benazepril). BP control rate was 83.8% with amlodipine/benazepril 2.5/10 mg, 80.2% with amlodipine/benazepril 5/10 mg, 64.9% with benazepril 10 mg at study end (p < 0.01, combination versus benazepril). Three groups were generally well tolerated. Our study indicated that amlodipine/benazepril fixed-dose combination offered significant additional BP reductions and BP control rate compared with the continuation of benazepril monotherapy. No significant differences were observed in both BP reductions and BP control rate between amlodipine/benazepril 2.5/10 mg and amlodipine/benazepril 5/10 mg.

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.

Single-pill combination of telmisartan/amlodipine versus amlodipine monotherapy in diabetic hypertensive patients: an 8-week randomized, parallel-group, double-blind trial

BACKGROUND

Hypertensive patients with diabetes often require combination therapy to achieve a blood pressure (BP) goal, and evidence suggests that time to BP goal is crucial to decrease cardiovascular risk.

OBJECTIVE

The aim of the study was to investigate whether the single-pill combination of telmisartan and amlodipine was superior to amlodipine alone as initial antihypertensive therapy in patients with diabetes and hypertension.

METHODS

An 8-week, randomized, parallel-group, double-blind international trial comparing the once-daily single-pill combination of telmisartan 80 mg and amlodipine 10 mg (T/A; n = 352) with once-daily amlodipine 10 mg (A; n = 354) in patients with type 2 diabetes mellitus and stage 1 or 2 hypertension (systolic BP [SBP] >150 mm Hg).

RESULTS

Patient demographics were similar between treatment groups, with an mean (SD) age of 60.5 (10.1) years; 51.7% were male, the mean (SD) body mass index was 32.0 (6.1) and the mean (SD) duration of hypertension was 8.8 (7.9) years. After 8 weeks (primary end point) as well as after 1, 2, and 4 weeks (key secondary end points), significantly greater decreases in the in-clinic mean seated trough cuff SBP with T/A versus A were achieved (-29.0 mm Hg vs -22.9 mm Hg at 8 weeks; P < 0.0001). After 8 weeks, 71.4% versus 53.8% of patients achieved the BP goal (<140/90 mm Hg) with T/A versus A, with mean SBPs of 131.9 and 137.9 mm Hg, respectively. Similar results were observed in the obese (metabolic syndrome) subpopulation. The more stringent goal (<130/80 mm Hg) was achieved by 36.4% and 17.9% patients in the T/A and A groups, respectively. The most common adverse events were peripheral edema, headache, and dizziness.

CONCLUSIONS

In this selected population of patients with diabetes and hypertension, T/A provided prompt and greater BP decreases compared with A monotherapy, with the majority of patients achieving the BP goal (<140/90 mm Hg).

Hydrochlorothiazide versus calcium channel blockers: what is the best add-on to a renin-angiotensin system blocker for treating hypertension in patients with renal disease?

Hypertension remains an important problem that increases the risk of cardiovascular disease and is a leading cause of mortality worldwide. Achieving long-term control of arterial hypertension, which has an estimated prevalence of 28% in the US adult population, would translate into a significant reduction in cardiovascular events. Specific causes can be identified and treated for certain forms of secondary hypertension, but often it is multifactorial. Therefore, it makes sense to attain blood pressure control by addressing more than one pressor mechanism. Several clinical studies have demonstrated that combination antihypertensive therapy is more effective than monotherapy, and a review of currently published data suggests that approximately 75% of hypertensive individuals will require some form of combination therapy to achieve target blood pressure (BP) goals. To this end, the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of Blood Pressure (JNC 7) has recommended that antihypertensive therapy should start with two drugs when a patient presents with systolic blood pressure (SBP) more than 20 mm Hg above target levels, diastolic blood pressure (DBP) more than 10 mm Hg above target levels, or both. This review attempts to analyze the current evidence in published medical literature to answer the question of whether hydrochlorothiazide or a calcium channel blocker is a better add-on to a renin-angiotensin system blocker for treating hypertension in patients with renal disease.

Olmesartan/amlodipine: a review of its use in the management of hypertension

Combination therapy is an effective strategy to increase antihypertensive efficacy in those patients with poor blood pressure (BP) control. In order to achieve BP targets, at least 75% of patients may require combination therapy, and European guidelines advocate this approach, particularly in those patients with a high cardiovascular risk. Evidence from large, randomized controlled trials, and the European hypertension treatment guidelines is supportive of the use of an angiotensin receptor blocker (ARB) with a calcium channel blocker (CCB). Fixed-dose combination formulations of olmesartan medoxomil, an ARB, and the CCB amlodipine are approved in several European countries for patients with essential hypertension. The olmesartan/amlodipine combination has demonstrated greater efficacy than its component monotherapies in reducing BP in patients with mild-to-severe hypertension. Significantly greater reductions in seated diastolic BP were observed between baseline and after eight weeks of treatment with olmesartan/amlodipine, compared with equivalent doses of olmesartan or amolodipine monotherapy (P < 0.001), in the factorial Combination of Olmesartan Medoxomil and Amlodipine Besylate in Controlling High Blood Pressure (COACH) trial. About 85% of the maximal BP reductions after the 8-week treatment period were already observed after two weeks. Uptitration as necessary, with or without hydrochlorothiazide, allowed the majority of patients to achieve BP control in a 44-week open-label extension treatment period to the COACH trial. The use of olmesartan/amlodipine allowed up to 54% of patients, with previously inadequate responses to amlodipine or olmesartan monotherapy, to achieve their BP goals. Data from post-registration studies using tight BP control and forced titration regimens have further demonstrated the high efficacy of olmesartan/amlodipine in achieving BP goal rates. Moreover, consistent reductions in BP were observed over the 24-hour dosing interval using ambulatory measurements. Olmesartan/amlodipine was generally well tolerated over the short- and long-term, with a lower frequency of peripheral edema with olmesartan/amlodipine 40/10 mg than with amlodipine 10 mg monotherapy.

Effect of renin-angiotensin system blockade on calcium channel blocker-associated peripheral edema

BACKGROUND

Peripheral edema is a common adverse effect of calcium channel blockers. The addition of a renin-angiotensin system blocker, either an angiotensin-converting enzyme inhibitor or an ARB, has been shown to reduce peripheral edema in a dose-dependent way.

METHODS

We performed a MEDLINE/COCHRANE search for all prospective randomized controlled trials in patients with hypertension, comparing calcium channel blocker monotherapy with calcium channel blocker/renin-angiotensin system blocker combination from 1980 to the present. Trials reporting the incidence of peripheral edema or withdrawal of patients because of edema and total sample size more than 100 were included in this analysis.

RESULTS

We analyzed 25 randomized controlled trials with 17,206 patients (mean age 56 years, 55% were men) and a mean duration of 9.2 weeks. The incidence of peripheral edema with calcium channel blocker/renin-angiotensin system blocker combination was 38% lower than that with calcium channel blocker monotherapy (P<.00001) (relative risk [RR] 0.62; 95% confidence interval [CI], 0.53-0.74). Similarly, the risk of withdrawal due to peripheral edema was 62% lower with calcium channel blocker/renin-angiotensin system blocker combination compared with calcium channel blocker monotherapy (P=.002) (RR 0.38; 95% CI, 0.22-0.66). ACE inhibitors were significantly more efficacious than ARBs in reducing the incidence of peripheral edema (P<.0001) (ratio of RR 0.74; 95% CI, 0.64-0.84) (indirect comparison).

CONCLUSION

In patients with hypertension, the calcium channel blocker/renin-angiotensin system blocker combination reduces the risk of calcium channel blocker-associated peripheral edema when compared with calcium channel blocker monotherapy. ACE inhibitor seems to be more efficacious than ARB in reducing calcium channel blocker-associated peripheral edema, but head-to-head comparison studies are needed to prove this.

Combination therapy in hypertension

The goal of antihypertensive therapy is to abolish the risks associated with blood pressure (BP) elevation without adversely affecting quality of life. Drug selection is based on efficacy in lowering BP and in reducing cardiovascular (CV) end points, including stroke, myocardial infarction, and heart failure. Although the choice of initial drug therapy exerts some effect on long-term outcomes, it is evident that BP reduction per se is the primary determinant of CV risk reduction. Available data suggest that at least 75% of patients will require combination therapy to achieve contemporary BP targets, and increasing emphasis is being placed on the practical tasks involved in consistently achieving and maintaining goal BP in clinical practice. It is within this context that the American Society of Hypertension presents this Position Paper on Combination Therapy for Hypertension. It will address the scientific basis of combination therapy, present the pharmacologic rationale for choosing specific drug combinations, and review patient selection criteria for initial and secondary use. The advantages and disadvantages of single-pill (fixed) drug combinations and the implications of recent clinical trials involving specific combination strategies will also be discussed.

Amlodipine and angiotensin-converting enzyme inhibitor combination versus amlodipine monotherapy in hypertension: a meta-analysis of randomized controlled trials

OBJECTIVE

This study aimed to estimate the efficacy and tolerability of the combination of amlodipine and angiotensin-converting enzyme inhibitors as compared with amlodipine monotherapy in the treatment of hypertension.

METHODS

The Cochrane Central Register of Controlled Trials, PubMed, and Embase were searched for relevant articles. A random effect model of meta-analysis was used for the selected randomized controlled trials (RCTs).

RESULTS

A total of 17 randomized controlled trials involving 3291 patients were identified using predefined criteria. The combination treatment of amlodipine and angiotensin-converting enzyme inhibitors resulted in a greater reduction of both systolic blood pressure (SBP) [weighted mean difference (WMD) 5.72, 95% CI: (confidence interval) 4.10-7.33] and diastolic blood pressure (DBP) (WMD 3.62, 95% CI: 4.85-2.39) than monotherapy. The combination treatment also generated significantly greater reductions for the mean ambulatory SBP and DBP during the full 24 hours (WMD: SBP 4.24, 95% CI: 6.82-1.67; DBP 2.23, 95% CI: 3.73-0.69), but not for the trough (WMD: SBP 4.52, 9.56 to -0.51; DBP 3.7, 7.65 to -0.25). The hypertension therapeutic control (SPB <140, DBP <90 mmHg) rate for the combination treatment is higher than that for monotherapy [relative risk (RR): 1.36, 95% CI: 1.07-1.73]. The combination treatment also resulted in a lower overall rate of adverse events (RR: 0.86, 95% CI: 0.75-0.99) and edema (RR: 0.40, 95% CI: 0.29-0.56), but a higher rate of cough (RR: 3.28, 95% CI: 2.03-5.29) as compared with monotherapy.

CONCLUSION

This meta-analysis suggests that the combination treatment provides superior BP control, fewer adverse events, and better tolerability in hypertensive patients than monotherapy. Further research should explore the mechanism of the combination therapy and whether it is associated with the reduction of cardiovascular disease morbidity and mortality.

Combination therapy in hypertension

The goal of antihypertensive therapy is to abolish the risks associated with blood pressure (BP) elevation without adversely affecting quality of life. Drug selection is based on efficacy in lowering BP and in reducing cardiovascular (CV) end points including stroke, myocardial infarction, and heart failure. Although the choice of initial drug therapy exerts some effect on long-term outcomes, it is evident that BP reduction per se is the primary determinant of CV risk reduction. Available data suggest that at least 75% of patients will require combination therapy to achieve contemporary BP targets, and increasing emphasis is being placed on the practical tasks involved in consistently achieving and maintaining goal BP in clinical practice. It is within this context that the American Society of Hypertension presents this Position Paper on Combination Therapy for Hypertension. It will address the scientific basis of combination therapy, present the pharmacologic rationale for choosing specific drug combinations, and review patient selection criteria for initial and secondary use. The advantages and disadvantages of single pill (fixed) drug combinations, and the implications of recent clinical trials involving specific combination strategies will also be discussed.

Unmet needs in managing hypertension: potential role of direct renin inhibition

Hypertension is the most prevalent and important risk factor for cardiovascular and renal disease worldwide. Despite the large armamentarium of available blood pressure-lowering agents, the need remains for safer and more effective antihypertensive treatment. Based on current target levels of < 140/90 mm Hg, only one-third of hypertensive Americans have achieved goal blood pressure. Several strategies can help address these challenges, including increasing public awareness, and improving physician awareness of evidence-based therapeutic guidelines. There also remains a need for new therapeutic options. This review examines new developments among those agents having inhibitory activity on the renin-angiotensin-aldosterone system (RAAS). All currently available RAAS blockers cause a reactive increase in plasma renin concentration. However, the direct renin inhibitors are the only class that diminishes plasma renin activity, an effect that may provide additional cardiovascular and/or renoprotective benefit. Aliskiren is the first clinically available direct renin inhibitor that has been shown to be effective and well tolerated both as monotherapy and in combination with other established agents in hypertensive patients. Randomized clinical trials are underway to explore the extent to which direct renin inhibition provides additive protection against cardiovascular and renal disease events.

The effects of high‐dose amlodipine/benazepril combination therapies on blood pressure reduction in patients not adequately controlled with amlodipine monotherapy

BACKGROUND

This study compared the efficacy and safety of amlodipine/benazepril (10/40 mg/day and 10/20 mg/day) with amlodipine 10 mg/day in patients whose blood pressure (BP) was not adequately controlled with amlodipine monotherapy.

METHODS

After a lead-in period with amlodipine monotherapy, 812 non-responder patients (mean sitting diastolic BP > or =95 mmHg) were randomized to one of three treatment groups. Ambulatory BP monitoring was conducted in 276 patients.

RESULTS

Treatment with amlodipine/benazepril 10/40 mg/day and 10/20 mg/day resulted in a decrease of mean sitting systolic and mean sitting diastolic BP by 13.3/12.7 mmHg and 12.1/11.6 mmHg, respectively, compared with monotherapy (6.6/8.5 mmHg) (p < 0.0001). Both combinations resulted in more responders than monotherapy (74% and 65% vs. 54%; p < 0.0001 and p < 0.0085, respectively). Amlodipine/benazepril 10/40 mg/day and 10/20 mg/day decreased ambulatory systolic and diastolic BP by 9.9/6.7 mmHg and 7.4/5.2 mmHg compared with monotherapy (p < 0.0001). The incidence of pedal edema was lower in the amlodipine/benazepril combinations compared with monotherapy (4.5%, 5.5% vs. 9.2%, respectively, p=NS). No significant metabolic side-effects were noted among the combination groups.

CONCLUSION

Amlodipine/benazepril combinations were well tolerated and resulted in significant BP reductions and better BP responder rates than amlodipine monotherapy.

Effects of nifedipine GITS 20 mg or enalapril 20 mg on blood pressure and inflammatory markers in patients with mild–moderate hypertension

OBJECTIVE

Calcium antagonists, angiotensin-converting enzyme (ACE) inhibitors and other drug classes either alone or in combination have been recommended for the treatment of hypertension. Nifedipine gastrointestinal therapeutic system (GITS) 20 mg is a new low-dose formulation with an improved tolerability. The aim of the present study was to compare the effects of nifedipine GITS 20 mg and enalapril 20 mg on blood pressure and circulating adhesion molecules in hypertensive patients.

METHODS

This randomized, double-blind, multicentre trial compared the blood pressure lowering effects of a 12-week treatment of nifedipine GITS 20 mg vs enalapril 20 mg in 264 patients with mild-to-moderate hypertension.

RESULTS

Nifedipine GITS 20 mg induced a reduction of clinic blood pressure, which was similar to that observed with enalapril 20 mg. Nifedipine GITS and enalapril lowered mean sitting diastolic blood pressure by 11.8 and 12.4 mmHg, respectively, while systolic blood pressure was reduced by 15.3 and 16.3 mmHg, respectively. Ambulatory blood pressure monitoring-derived blood pressure data showed similar results in both groups without any statistically significant differences between treatments. Both enalapril and nifedipine tended to reduce ICAM-1 and E-selectin, while only nifedipine reduced von Willebrand factor. Both treatments were well tolerated.

CONCLUSIONS

Our findings demonstrate a similar antihypertensive effectiveness of a low dose (20 mg) of nifedipine GITS in comparison with a standard dose of enalapril (20 mg). Given its clinical efficacy and good tolerability, low-dose nifedipine GITS may be considered a valuable treatment option for hypertensive patients.

Choice of ACE inhibitor combinations in hypertensive patients with type 2 diabetes: update after recent clinical trials

The diabetes epidemic continues to grow unabated, with a staggering toll in micro- and macrovascular complications, disability, and death. Diabetes causes a two- to fourfold increase in the risk of cardiovascular disease, and represents the first cause of dialysis treatment both in the UK and the US. Concomitant hypertension doubles total mortality and stroke risk, triples the risk of coronary heart disease and significantly hastens the progression of microvascular complications, including diabetic nephropathy. Therefore, blood pressure reduction is of particular importance in preventing cardiovascular and renal outcomes. Successful antihypertensive treatment will often require a combination therapy, either with separate drugs or with fixed-dose combinations. Angiotensin converting enzyme (ACE) inhibitor plus diuretic combination therapy improves blood pressure control, counterbalances renin-angiotensin system activation due to diuretic therapy and reduces the risk of electrolyte alterations, obtaining at the same time synergistic antiproteinuric effects. ACE inhibitor plus calcium channel blocker provides a significant additive effect on blood pressure reduction, may have favorable metabolic effects and synergistically reduce proteinuria and the rate of decline in glomerular filtration rate, as evidenced by the GUARD trial. Finally, the recently published ACCOMPLISH trial showed that an ACE inhibitor/calcium channel blocker combination may be particularly useful in reducing cardiovascular outcomes in high-risk patients. The present review will focus on different ACE inhibitor combinations in the treatment of patients with type 2 diabetes mellitus and hypertension, in the light of recent clinical trials, including GUARD and ACCOMPLISH.

Combination therapy versus monotherapy in reducing blood pressure: meta-analysis on 11,000 participants from 42 trials

OBJECTIVE

To quantify the incremental effect of combining blood pressure-lowering drugs from any 2 classes of thiazides, beta-blockers, angiotensin-converting enzyme inhibitors, and calcium channel blockers over 1 drug alone and to compare the effects of combining drugs with doubling dose.

METHODS

Meta-analysis of factorial trials in which participants were randomly allocated to 1 drug alone, another drug alone, both drugs together, or a placebo.

RESULTS

We identified 42 trials (10,968 participants). With a thiazide used alone, the mean placebo-subtracted reduction in systolic blood pressure was 7.3 mm Hg and 14.6 mm Hg combined with a drug from another class. The corresponding reductions were 9.3 mm Hg and 18.9 mm Hg with a beta-blocker, 6.8 mm Hg and 13.9 mm Hg with an angiotensin-converting enzyme, and 8.4 mm Hg and 14.3 mm Hg with a calcium channel blocker. The expected blood pressure reduction from 2 drugs together, assuming an additive effect, closely predicted the observed blood pressure reductions. The ratios of the observed to expected incremental blood pressure reductions from combining each class of drug with any other over that from 1 drug were, respectively, for thiazides, beta-blockers, angiotensin-converting enzyme inhibitors, and calcium channel blockers: 1.04 (95% confidence interval [CI], 0.88-1.20), 1.00 (95% CI, 0.76-1.24), 1.16 (95% CI, 0.93-1.39), and 0.89 (95% CI, 0.69-1.09); the overall average was 1.01 (95% CI, 0.90-1.12). Comparison of our results with those of a published meta-analysis of different doses of the same drug showed that doubling the dose of 1 drug had approximately one fifth of the equivalent incremental effect (0.22 [95% CI, 0.19-0.25]).

CONCLUSION

Blood pressure reduction from combining drugs from these 4 classes can be predicted on the basis of additive effects. The extra blood pressure reduction from combining drugs from 2 different classes is approximately 5 times greater than doubling the dose of 1 drug.

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

BACKGROUND

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

SCOPE

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

FINDINGS

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

CONCLUSION

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

Efficacy and safety of olmesartan medoxomil and hydrochlorothiazide compared with benazepril and amlodipine besylate

BACKGROUND

Most patients with stage 2 hypertension require two or more antihypertensive agents in order to achieve the BP goals recommended in current treatment guidelines. Accordingly, combinations of two drugs with different mechanisms of antihypertensive action are widely used.

OBJECTIVE

The aim of this randomized, double-blind, multicenter 12-week study was to compare the efficacy, safety, and tolerability of a combination of olmesartan medoxomil/hydrochlorothiazide (HCTZ) with that of benazepril plus amlodipine besylate in patients with stage 2 hypertension.

METHODS

Patients were eligible for randomization following a 3- to 4-week placebo run-in period if they had either (i) mean seated DBP>or=90 mm Hg but<115 mm Hg and mean seated SBP>or=160 mm Hg but <200 mm Hg, or (ii) mean seated DBP>or=100 mm Hg but<115 mm Hg. The difference in mean seated SBP measured on two separate visits during the run-in period was required to be<or=15 mm Hg. In addition, a mean 8-hour daytime ambulatory DBP>or=95 mm Hg and<115 mm Hg or SBP>145 mm Hg and<or=190 mm Hg were required. Eligible patients were randomized 1:1 to treatment with olmesartan medoxomil (20 mg/day for 2 weeks; then 40 mg/day for 2 weeks; then olmesartan medoxomil/HCTZ 40/12.5 mg/day for 4 weeks; then olmesartan medoxomil/HCTZ 40/25 mg/day for 4 weeks) or benazepril (10 mg/day for 2 weeks; then 20 mg/day for 2 weeks; then benazepril 20 mg/day plus amlodipine besylate 5 mg/day for 4 weeks; then benazepril 20 mg/day plus amlodipine besylate 10 mg/day for 4 weeks). The primary endpoint was change from baseline in mean SBP at the end of week 12 (end of study). Secondary endpoints included DBP after completion of monotherapy and combination therapy at the end of weeks 4 and 12, SBP at the end of week 4, and percentage of patients attaining BP goals of<140/90 mm Hg, <130/85 mm Hg, and<130/80 mm Hg at the end of weeks 4 and 12.

RESULTS

One-hundred and ninety patients were randomized and received at least one dose of study medication. The primary efficacy endpoint of change in mean seated SBP at week 12 was significantly greater with olmesartan medoxomil/HCTZ than with benazepril plus amlodipine besylate (least square [LS] mean change: -32.5 vs -26.5 mm Hg, p=0.024; LS mean treatment difference -6.0 mm Hg; 95% CI -11.1, -0.8 mm Hg). The LS mean change for reduction in DBP approached statistical significance with olmesartan medoxomil/HCTZ compared with the benazepril-based regimen (p=0.056) at week 12 (end of study). BP reductions showed statistically significant differences between treatment groups favoring olmesartan medoxomil/HCTZ in both SBP and DBP at week 8. The percentage of patients achieving goal rates at the end of the study for olmesartan medoxomil/HCTZ and benazepril plus amlodipine besylate, respectively, were 66.3% versus 44.7% (p=0.006) for<140/90 mm Hg, 44.9% versus 21.2% (p=0.001) for<130/85 mm Hg, and 32.6% versus 14.1% (p=0.006) for<130/80 mm Hg. Both treatments were well tolerated.

CONCLUSIONS

Olmesartan medoxomil/HCTZ 40/12.5 and 40/25 mg/day combination therapy was well tolerated and demonstrated a greater antihypertensive effect than benazepril plus amlodipine besylate 20/5 and 20/10 mg/day and this enabled more patients to achieve targeted BP goals.

Two multicenter, 8-week, randomized, double-blind, placebo-controlled, parallel-group studies evaluating the efficacy and tolerability of amlodipine and valsartan in combination and as monotherapy in adult patients with mild to moderate essential hypertension

BACKGROUND

Patients with hypertension may require combination therapy to attain the blood pressure targets recommended by US and European treatment guidelines. Combination therapy with a calcium channel blocker and an angiotensin II-receptor blocker would be expected to provide enhanced efficacy.

OBJECTIVES

Two studies were conducted to compare the efficacy of various combinations of amlodipine and valsartan administered once daily with their individual components and placebo in patients with mild to moderate essential hypertension (mean sitting diastolic blood pressure [MSDBP] >/=95 and < 110 mm Hg). A secondary objective was to evaluate safety and tolerability.

METHODS

The 2 studies were multinational, multicenter, 8-week, randomized, double-blind, placebo-controlled, parallel-group trials. In study 1, patients were randomized to receive amlodipine 2.5 or 5 mg once daily, valsartan 40 to 320 mg once daily, the combination of amlodipine 2.5 or 5 mg with valsartan 40 to 320 mg once daily, or placebo. In study 2, patients were randomized to receive amlodipine 10 mg once daily, valsartan 160 or 320 mg once daily, the combination of amlodipine 10 mg with valsartan 160 or 320 mg once daily, or placebo. The primary efficacy variable in both studies was change from baseline in MSDBP at the end of the study. Secondary variables included the change in mean sitting systolic blood pressure (MSSBP), response rate (the proportion of patients achieving an MSDBP <90 mm Hg or a >/= 10-mm Hg decrease from baseline), and control rate (the proportion of patients achieving an MSDBP <90 mm Hg). Safety was assessed in terms of adverse events (spontaneously reported or elicited by questioning), vital signs, and laboratory values.

RESULTS

A total of 1911 patients were randomized to treatment in study 1 (1022 amlodipine + valsartan; 507 valsartan; 254 amlodipine; 128 placebo); 1250 were randomized to treatment in study 2 (419, 415, 207, and 209, respectively). In all treatment groups in both studies, the majority of patients were white (79.5% study 1, 79.4% study 2) and male (53.5% and 50.3%, respectively). The overall mean age was 54.4 years in study 1 and 56.9 years in study 2. The mean weight of patients in study 1 was higher than that in study 2 (88.8 vs 79.7 kg). The overall baseline mean sitting BP was 152.8/99.3 mm Hg in study 1 and 156.7/99.1 mm Hg in study 2. With the exception of a few combinations that included amlodipine 2.5 mg, the combination regimens in both studies were associated with significantly greater reductions in MSDBP and MSSBP compared with their individual components and placebo (P < 0.05). A positive dose response was observed for all combinations. The highest response rate in study 1 was associated with the highest dose of combination therapy (amlodipine 5 mg + valsartan 320 mg: 91.3%). Amlodipine 5 mg, valsartan 320 mg, and placebo were associated with response rates of 71.9%, 73.4%, and 40.9%, respectively. In study 2, the 2 doses of combination therapy were associated with similar response rates (amlodipine 10 mg + valsartan 160 mg: 88.5%; amlodipine 10 mg + valsartan 320 mg: 87.5%). Amlodipine 10 mg was associated with a response rate of 86.9%; valsartan 160 and 20 mg were associated with response rates of 74.9% and 72.0%, respectively; and placebo was associated with a response rate of 49.3%. Control rates followed a similar pattern. The incidence of peripheral edema with combination therapy was significantly lower compared with amlodipine monotherapy (5.4% vs 8.7%, respectively; P = 0.014), was significantly higher compared with valsartan monotherapy (2.1%; P < 0.001), and did not differ significantly from placebo (3.0%).

CONCLUSIONS

In these adult patients with mild to moderate hypertension, the combination of amlodipine + valsartan was associated with significantly greater blood pressure reductions from baseline compared with amlodipine or valsartan monotherapy or placebo. The incidence of peripheral edema was significantly lower with combination therapy than with amlodipine monotherapy.

Hypertension‐Related Morbidity and Mortality in African Americans—Why We Need to Do Better

Almost one third of adults in the United States have hypertension. Prevalence data among different racial or ethnic groups indicate that a disproportionate number of African Americans have hypertension compared with non-Hispanic whites and Mexican Americans. Earlier onset of high blood pressure and greater severity of hypertension contribute to a greater burden of hypertensive target organ damage in African Americans and may be a factor in the shorter life expectancy of this population compared with white Americans. There is a clear need for improved management of hypertension in African Americans via therapeutic lifestyle interventions and pharmacotherapy. While there is some evidence that particular antihypertensive agent classes provide blood pressure-lowering advantages over others, there is no support for withholding agents of any one class. When given as monotherapy, diuretics and calcium channel blockers may be relatively more effective in lowering blood pressure in African Americans than beta blockers, angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers. However, when combined with a diuretic, African Americans respond as well to these agents as other racial groups. Combination therapy using antihypertensive agents with differing modes of action provides additive antihypertensive efficacy and is well tolerated. Recent guidelines recommend combination therapy as the standard of care for patients with significant blood pressure elevation, especially those with diabetes mellitus and renal disease. These comorbidities are more common in African Americans and indicate the potential need for initial therapy with more than one agent or a combination of agents in one pill.

Fixed-dose combination antihypertensives and reduction in target organ damage: are they all the same?

Hypertension is a multifactorial disorder leading to pathophysiologic changes in target organs over time through diverse mechanisms. In addition, hypertension frequently resists control with monotherapy, necessitating combination therapy with two or more antihypertensive agents. Many currently available fixed-dose antihypertensive combinations combine drugs with different, but complementary, mechanisms of action to improve overall efficacy and tolerability. In addition, it is possible to select drug combinations whereby one drug offsets the negative effects of the other drug. Fixed-dose antihypertensive combinations may provide significant advantages over high-dose monotherapy, such as improved BP-lowering efficacy, reduced adverse event frequency, improved patient compliance, potentially lower treatment costs, and shorter time to BP control. Combination therapy has been recommended as potential first-line therapy in recent consensus guideline statements, especially for higher-risk patients, such as those with stage 2 hypertension. The combination of a renin-angiotensin-aldosterone system-targeting agent, such as an ACE inhibitor or angiotensin II receptor antagonist (ARB), and a diuretic or calcium channel antagonist appears to provide synergy with regard to BP lowering. In addition, ACE inhibitors and ARBs have demonstrated beneficial effects beyond BP reduction, reducing cardiovascular morbidity and mortality, inhibiting development and progression of type 2 diabetes mellitus and the progression of renal disease. Preliminary studies of fixed-dose combinations have shown reductions in left ventricular hypertrophy and improvements in markers of renal function. Additional studies currently underway will compare the effects of available fixed-dose combinations on cardiovascular morbidity and mortality, and markers of renal dysfunction.

Optimal Vascular Protection: A Case for Combination Antihypertensive Therapy

Endothelial dysfunction is an important factor in the pathogenesis of atherosclerosis, hypertension, and heart failure. The endothelium mediates vascular tone, structure, and function by the release and regulation of multiple vasoactive substances that promote or inhibit vasodilation, vasoconstriction, cell growth, and other mechanisms. The effect of antihypertensive drugs on endothelial function may be an important indicator of their ability to reduce risks for cardiovascular morbidity and mortality. Endothelium-dependent vasodilation induced by various antihypertensive drugs is accurately measured with high-resolution ultrasound of flow-mediated dilation of the brachial artery. Calcium channel blockers and angiotensin-converting enzyme inhibitors have been shown to reverse endothelial dysfunction. The benefits of angiotensin-converting enzyme inhibitors and calcium channel blockers on the endothelium are believed to derive from their effects on nitric oxide production and antioxidant effects, possibly independent of blood pressure reduction. Due to their complementary mechanisms of action, it has been hypothesized that the combination of an angiotensin-converting enzyme inhibitor and a calcium channel blocker will provide superior cardiovascular protection, in part by producing an additive effect of increased nitric oxide availability, when compared with either agent alone.

Stability indicating RP-HPLC method for simultaneous determination of amlodipine and benazepril hydrochloride from their combination drug product

A stability indicating reversed-phase HPLC method has been developed and subsequently validated for simultaneous estimation of amlodipine (AM) present as amlodipine besylate (AB), and benazepril hydrochloride (BH) from their combination product. The proposed RP-HPLC method utilizes a Zorbax SB C18, 5 microm, 250 mm x 4.6 mm i.d. column, mobile phase consisting of phosphate buffer and acetonitrile in the proportion of 65:35 (v/v) with apparent pH adjusted to 7.0, and UV detection at 240 nm using a photodiode array detector. AB, BH, and their combination drug product were exposed to thermal, photolytic, hydrolytic, and oxidative stress conditions, and the stressed samples were analysed by the proposed method. Peak homogeneity data of AM and BH peaks obtained using photodiode array detector, in the stressed sample chromatograms, demonstrated the specificity of the method for their estimation in presence of degradants. The described method was linear over a range of 6-14 microg/ml for AM and 12-28 microg/ml for BH. The mean recoveries were 99.91 and 100.53% for AM and BH, respectively. F-test and t-test at 95% confidence level were used to check the intermediate precision data obtained under different experimental setups; the calculated value was found to be less than critical value.

Drug treatment of essential hypertension: the case for initial combination therapy

Essential hypertension is a major cause of cardiovascular morbidity and mortality in the Western world, yet it remains poorly controlled. Single drug-antihypertensive therapy is unsuccessful in up to half of all patients with hypertension; although lack of adherence may account for a proportion of this, there is evidence of considerable variation in the response of different hypertensive patients to different drug classes. A number of algorithms have been proposed in the literature, with a view to predicting an individual's response to different antihypertensive agents. However, even using such algorithms, hypertension control remains problematic, and they are frequently difficult to apply in everyday clinical practice. Initiation of treatment with low-dose combination antihypertensive therapy, using a drug which reduces total body sodium and/or volume in combination with a drug which blocks the renin-angiotensin system, provides an effective and easily applicable means to improve hypertension control in the primary care setting.

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

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

Adherence to Antihypertensive Therapy With Fixed-Dose Amlodipine Besylate/Benazepril HCl Versus Comparable Component-Based Therapy

Adhering to medication regimens has the potential to significantly improve clinical outcomes for persons with high blood pressure. A patient-related factor likely to affect adherence to treatment is the convenience of the prescribed drug regimen. The authors hypothesized that medication adherence would be superior and cost benefits would accrue in subjects who receive a once-daily, single-capsule, fixed-dose combination product for blood pressure control, compared with subjects who receive a similar regimen of separate components. A managed care organization that provides benefits for members enrolled in various health plans provided the data for this retrospective analysis. The database was used to assess medication adherence patterns for two groups of hypertensive subjects. Group 1 included subjects who had been prescribed the single-capsule, fixed-dose combination of amlodipine besylate/benazepril HCl. Group 2 comprised subjects who had been prescribed a regimen including an angiotensin-converting enzyme inhibitor and a dihydropyridine calcium channel blocker as separate drugs. Adherence was measured by the medication possession ratio, and medical resource utilization by the two groups was assessed during the study period. Group 1 (n=2754) and Group 2 (n=2978) were balanced with regard to age (mean, 53 years; range, 18-64 years) and sex (men, 50%; women, 50%). The overall medication possession ratio for Group 1 was significantly higher than that for Group 2 (80.8% vs. 73.8%; p<0.001). The average annual cost of cardiovascular-related care per subject was significantly lower in Group 1 compared with Group 2 (p<0.001). Subjects receiving the once-daily, single-capsule, fixed-dose combination of amlodipine/benazepril HCl demonstrated significantly better medication adherence and required fewer medical resources than did subjects receiving an angiotensin-converting enzyme inhibitor and a dihydropyridine calcium channel blocker as separate components.

Antihypertensive efficacy and safety of olmesartan medoxomil compared with amlodipine for mild-to-moderate hypertension

The antihypertensive efficacy of the angiotensin II receptor blocker olmesartan medoxomil has been shown to compare favourably with that of other antihypertensive agents. This randomized, double-blind study compared the antihypertensive efficacy of the starting dose of olmesartan medoxomil with that of the calcium channel blocker amlodipine besylate (amlodipine) in subjects with mild-to-moderate hypertension. Following a 4-week, single-blind, placebo run-in period, 440 subjects aged >/=18 years were randomized to the starting dose of olmesartan medoxomil (20 mg/day), amlodipine (5 mg/day), or placebo for 8 weeks. Subjects were evaluated by 24-h ambulatory blood pressure monitoring (ABPM) and by seated cuff blood pressure (BP) measurements at trough. The primary end point was the change from baseline in mean 24-h diastolic blood pressure (DBP) by ABPM at Week 8. Secondary end points included change from baseline in mean 24-h ambulatory systolic blood pressure (SBP) at 8 weeks, change from baseline in mean seated trough cuff DBP and SBP measurements, and response and control rates for DBP <90 and <85 mmHg. Control rates for SBP <140 and <130 mmHg were also calculated. Olmesartan medoxomil and amlodipine produced significantly greater reductions in ambulatory and seated DBP and SBP compared with placebo. Mean reductions in ambulatory and seated BP were similar between the two active agents; however, in the olmesartan medoxomil group, significantly more patients achieved the SBP goal of <130 mmHg and the DBP goal of <85 mmHg. Both drugs were well tolerated at the recommended starting dose. Although amlodipine was associated with a higher incidence of oedema, this did not reach statistical significance. Olmesartan medoxomil is an effective antihypertensive agent, with BP-lowering efficacy at the starting dose similar to that of amlodipine, and is associated with more patients achieving the rigorous BP goals of SBP <130 mmHg and DBP <85 mmHg.

Results of a pilot pharmacotherapy quality improvement program using fixed-dose, combination amlodipine/benazepril antihypertensive therapy in a long-term care setting

BACKGROUND

Hypertension is common in older adults (aged > or =65 years). Treatment frequently requires multiple medications and can be expensive.

OBJECTIVE

This study measured the impact of substituting low-dose, fixed-combination therapy using the calcium channel blocker (CCB) amlodipine and the angiotensin-converting enzyme (ACE) inhibitor benazepril for high-dose CCB monotherapy or dual therapy with a CCB and an ACE inhibitor on antihypertensive drug costs, the incidence of adverse events, and blood-pressure control.

METHODS

A multicenter, pilot pharmacotherapy quality improvement program was undertaken in a long-term care facility setting. Consultant pharmacists reviewed pharmacy records and medical charts from long-term care facilities, identifying older patients with a diagnosis of hypertension who either took CCB concomitantly with an ACE inhibitor or experienced adverse events on high-dose CCB therapy. Eligible patients were identified and their physicians contacted regarding switching them to fixed-dose combination therapy.

RESULTS

A total of 51 patients at 17 facilities were switched to fixed-dose amlodipine/benazepril combination therapy; 94.1% were women and 5.9% were men (mean age, 85.1 years; range, 64-99 years). The mean number of comorbidities was 1.6. During the subsequent 2 months, mean blood pressure remained at levels similar to those at baseline. The number of patients reporting at least 1 drug-related adverse event decreased by 81.8% (P < 0.05), and the incidence of edema decreased by 75.0%. The mean per-patient cost of antihypertensive drugs decreased by 33.1% (P < 0.001), a mean per-patient savings of 19.21 US dollars per month.

CONCLUSION

In patients aged > or =65 years with hypertension in long-term care facilities, a change from high-dose CCB monotherapy or CCB/ACE-inhibitor dual therapy to fixed-dose combination amlodipine/benazepril therapy significantly reduced drug costs and the incidence of adverse events and maintained blood-pressure control.

Effect of amlodipine on systolic blood pressure

BACKGROUND

Systolic hypertension is the most common form of hypertension, particularly in people aged >60 years. Caused by decreased compliance of large arteries, systolic hypertension is an independent risk factor for cardiovascular disease. Recent studies have demonstrated that it is more important to control systolic blood pressure (SBP) than diastolic blood pressure (DBP).

OBJECTIVE

The objective of this study was to perform a systematic literature review to examine the effectiveness of amlodipine in lowering SBP in a variety of patient subgroups and clinical settings.

METHODS

The literature review methodology included identifying, selecting, appraising, extracting, and synthesizing primary research studies. Following an a priori protocol, published literature was searched from 1980 to 2001 using 3 electronic databases. A manual review of the reference lists of recent review articles and all accepted studies was performed. Parallel-group, randomized, controlled trials that included at least 10 adults with baseline hypertension (SBP>or=140 mm Hg, DBP>or=90 mm Hg, or both), included at least 1 arm randomized to initial treatment with amlodipine monotherapy, had a minimum treatment duration of 8 weeks, and reported baseline and end-point blood pressure were included.

RESULTS

Of 696 citations identified, 85 primary studies met all inclusion criteria. Comparable treatment arms were pooled, and weightd mean SBP was calculated. In the amlodipine monotherapy arms, which included >5000 patients, SBP decreased by a mean of 17.5 mm Hg from baseline. The effect of amlodipine in reducing SBP was greater in elderly patients (age>or=60 years) and patients with author-defined isolated systolic hypertension. The dose was titrated to achieve the target blood pressure in 73 of 89 amlodipine treatment arms, whereas 16 treatment arms reported fixed doses. The median daily dose was 5 mg (range, 1.25-15 mg) in both the fixed-dose and dose-titration groups.

CONCLUSIONS

In this review of the published literature, amlodipine monotherapy was effective in reducing SBP. Antihypertensive agents such as amlodipine warrant consideration for the management of patients with inadequately controlled SBP.

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

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

Combination therapy of amlodipine/benazepril versus monotherapy of amlodipine in a practice-based setting

BACKGROUND

Community-based studies are conducted to determine the degree to which therapeutic interventions will succeed in real world settings. This large practice-based clinical trial assessed the efficacy and tolerability of fixed-dose combination therapy with amlodipine/benazepril, compared with amlodipine monotherapy, in patients with mild-to-moderate hypertension.

METHODS

Hypertensive patients currently taking amlodipine were selected based on one of two criteria: inadequate blood pressure (BP) control on amlodipine (diastolic BP [DBP] > or = 90 mm Hg; group 1), or inability to tolerate amlodipine (DBP < or = 90 mm Hg, but with edema; group 2). Eligible patients were switched from 5 or 10 mg of amlodipine to 5/10 mg or 5/20 mg of amlodipine/benazepril for 4 weeks. In group 1 (n = 6410), primary efficacy outcome was change in mean sitting DBP. A secondary efficacy outcome was change in mean sitting systolic BP (SBP). In group 2 (n = 1502), primary efficacy outcome was the percentage of patients whose edema improved during therapy with amlodipine/benazepril when compared with amlodipine monotherapy.

RESULTS

In group 1, mean sitting DBP declined from 96.5 mm Hg at baseline to 84.9 mm Hg at week 4, a mean reduction of 11.5 mm Hg (95% confidence interval [CI] -11.8 to -11.3 mm Hg; P < .001). From baseline to week 4, mean sitting SBP declined from 152.9 mm Hg to 137.3 mm Hg, a mean reduction of 15.6 mm Hg (95% CI -16.0 to -15.2 mm Hg; P < .001). In group 2, 85% (95% CI 83%-87%) experienced some improvement in edema compared with baseline levels.

CONCLUSIONS

Fixed-dose combination antihypertensive agent amlodipine/benazepril was safe and effective for patients who experienced either inadequate BP control or edema with amlodipine monotherapy.

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

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

Monotherapy versus combination therapy as first line treatment of uncomplicated arterial hypertension

Mild to moderate hypertension still remains poorly controlled. This relates to multiple factors including low antihypertensive efficacy of single drug therapies reluctance of primary care physicians to modify/titrate initially chosen therapy to obtain target blood pressure, and poor compliance with medication. Several guidelines for the treatment of high blood pressure now include combination therapy with low doses of 2 drugs as one of the strategies for the initial management of mild/moderate arterial hypertension. Evidence discussed in this article points to superior control of blood pressure by combinations of low doses of 2 drugs as compared with monotherapy in regular doses. This superior effectiveness of combined therapy relates to a better antihypertensive efficacy and higher response rates in the low range of doses as the result of complementary mechanisms of antihypertensive effects, better tolerance as a result of a lower rate of adverse effects in the low dose range, improved compliance from better tolerance and simple drug regimen, and lower cost. Whether increased use of fixed low dose combination therapies would translate to better control of arterial hypertension in the population and thereby further reduction of cardiovascular/cerebrovascular morbidity and mortality caused by hypertension remains to be assessed.

Efficacy and safety of a therapeutic interchange from high-dose calcium channel blockers to a fixed-dose combination of amlodipine/benazepril in patients with moderate-to-severe hypertension

BACKGROUND

Recent hypertension trials have demonstrated the importance of achieving goal blood pressures to reduce the risk of target organ damage. In patients with moderate to severe hypertension, the use of high-dose monotherapy and/or combinations of drugs are necessary to achieve these goals. Fixed-dose combination products may be useful in these patients by reducing the number of daily doses required to control blood pressure.

OBJECTIVE

The objective of the present study was to evaluate the efficacy and safety of a therapeutic interchange between high-dose calcium channel blocker therapy and a fixed-dose combination of amlodipine/ benazepril (Lotrel; Novartis Pharmaceuticals, USA) in patients with moderate to severe hypertension.

METHODS

A total of 75 patients were switched from amlodipine (n = 25), felodipine (n = 25), and nifedipine-GITS (n = 25) to amlodipine/benazepril. Twenty-eight of the 75 patients (37%) were taking either a beta-blocker or a diuretic in addition to the high-dose calcium channel blocker prior to the switch. Blood pressure control, side effects and the cost of the therapeutic interchange were evaluated in the year following the therapeutic interchange.

RESULTS

Sixty-six of the 75 (88%) patients were successfully switched with maintenance of blood pressure control and without the development of new dose-limiting side effects. Reasons for treatment failure after the therapeutic interchange included loss of blood pressure control in five patients and the development of new dose-limiting side effects in four patients. These side effects included cough in three patients and rash in one patient. After accounting for differences in drug acquisition cost and costs related to the switch (clinic and emergency room and laboratory tests), a cost savings of $16030 for all 75 patients was realised in the first year. The per patient-per year cost savings was $214.

CONCLUSIONS

Our data indicate that a therapeutic interchange from selected high-dose calcium channel blockers to a fixed-dose combination of amlodipine/ benazepril can be successfully accomplished in the majority of patients.

Once-daily treatment of patients with hypertension: a placebo-controlled study of amlodipine and benazepril vs amlodipine or benazepril alone

OBJECTIVE

To compare the efficacy, tolerability, and safety of once-daily therapy with amlodipine 5 mg/benazepril 10 mg vs amlodipine 5 mg, benazepril 10 mg, and placebo.

DESIGN

Randomised, double-blind, placebo-controlled, parallel-group, multicentre trial.

SETTING

Twenty-two clinical centres, including private practice groups and academic research clinics.

PATIENTS

A total of 530 patients between 21 and 80 years of age with essential hypertension were screened for the study, and 454 were randomised to treatment with amlodipine 5 mg/benazepril 10 mg, amlodipine 5 mg, benazepril 10 mg, or placebo for 8 weeks.

RESULTS

Amlodipine 5 mg/benazepril 10 mg produced greater reductions from baseline in sitting diastolic blood pressure than amlodipine 5 mg (P < 0.03), benazepril 10 mg (P < 0.001), and placebo (P < 0.001). The response rate in the amlodipine 5-mg/benazepril 10-mg treatment group (66.4%) was better than that observed in the amlodipine 5-mg (50.0% P < 0.02), benazepril 10-mg (38.3% P < 0.001), and placebo (24.4% P < 0.001) groups. There was no significant difference in heart rate among the four groups. The incidence of oedema in the amlodipine 5-mg/benazepril 10-mg (1.7%) group was somewhat less than that in the amlodipine 5-mg (4.5%) group.

CONCLUSIONS

Therapy with amlodipine 5 mg/benazepril 10 mg was well tolerated and was superior to amlodipine 5 mg, benazepril 10 mg, and placebo in reducing sitting diastolic blood pressure in patients with essential hypertension.

Choosing initial antihypertensive drug therapy for the uncomplicated hypertensive patient

Choosing the initial antihypertensive drug for the uncomplicated hypertensive patient is an important and frequent event for the primary care physician. Patients' first experience with antihypertensive drug therapy will likely affect their long-term perception of hypertension treatment. The choice should be made on the basis of sound scientific data and from the patient's perspective and needs. The drug should be taken once a day, should have proven efficacy in hypertension control and cardiovascular morbidity and mortality reduction, and should have as few side effects as possible. Low-dose thiazide diuretics meet this description, although the need to monitor electrolytes may make them less than ideal. The angiotensin II receptor antagonist class, with side-effects similar to those of placebo in controlled trials, is the most attractive from the patient's perspective, although outcome trial data do not yet exist proving that hypertension treatment with angiotensin II receptor antagonists reduces cardiovascular events. The angiotensin-converting enzyme inhibitors or angiotensin II receptor antagonists, with their low side-effect profiles and unique effects on vascular remodeling, are attractive second choices to combine with a diuretic if needed, although low-dose diuretic/Beta blocker combinations have also been shown to lower blood pressure with minimal side effects. At present, ensuring adequate long-term hypertension control is the most important aspect of hypertensive care, and which antihypertensive drug(s) the physician chooses can greatly affect the hypertensive patient's ability to achieve and to maintain long-term blood pressure control. (c)2001 by Le Jacq Communications, Inc.

Amlodipine/benazepril: fixed dose combination therapy for hypertension

Myocardial infarction, stroke, heart failure and end-stage renal disease have all been linked to inadequate control of blood pressure. Despite overwhelming evidence that uncontrolled hypertension is responsible for a sizeable number of adverse health-related outcomes, control of the disease remains considerably suboptimal. Available data demonstrate that in order to achieve adequate blood pressure control, a large number of patients require therapy with more than one medication. Fixed dose combination antihypertensive therapy has many advantages over other treatment options. Positive effects on blood pressure control, rates of adherence, adverse effects and cost have been identified. Amlodipine/benazepril (Lotrel), Novartis) is a fixed dose combination product indicated for the treatment of hypertension. Although not currently recommended as first-line therapy, studies confirm that this combination of a long-acting calcium antagonist and an angiotensin-converting enzyme (ACE) inhibitor possesses substantial blood pressure lowering capabilities. Whereas adverse events tend to become more frequent with increasing doses of antihypertensive monotherapy, the rate of adverse events attributed to amlodipine/benazepril in clinical trials often correlates with rates ascribed to placebo. Amlodipine/benazepril is capable of sustaining blood pressure control over a 24 h period and appears to be minimally affected by an occasional dose omission. Unlike the older calcium antagonists, amlodipine is unlikely to cause alterations in myocardial contractility. Additionally, the amlodipine/benazepril combination product costs less than the same therapy administered as the individual components. It is, therefore, reasonable to consider therapy with amlodipine/benazepril in appropriate patients after an adequate trial of antihypertensive monotherapy.

Amlodipine enhances NO production induced by an ACE inhibitor through a kinin-mediated mechanism in canine coronary microvessels

Our previous study found that angiotensin-converting enzyme (ACE) inhibitors and amlodipine induce NO release from coronary microvessels through a kinin-dependent mechanism. The goal of this study was to determine whether amlodipine could potentiate NO formation during ACE inhibition. Coronary microvessels were isolated from 16 mongrel dogs. Nitrite, the hydration product of NO, from coronary microvessels was quantified by using the Griess reaction. Bradykinin and kallikrein all significantly increased nitrite release from coronary microvessels in a concentration-dependent manner. The ACE inhibitor, ramiprilat, potentiated these effects. Amlodipine also markedly potentiated nitrite production by ramiprilat. For instance, amlodipine (10(-10) M) enhanced nitrite release induced by ramiprilat (10(-7) M) from 122 +/- 9 to 168 +/- 14 pmol/mg (p < 0.05 vs. ramiprilat). Nitrite release potentiated by ramiprilat and amlodipine was entirely blocked by N(omega)-nitro-L-arginine methyl ester (L-NAME, an inhibitor of NO synthase), HOE 140 (Icatibant, a specific B2-kinin receptor antagonist), and dichloroisocoumarin (DCIC, a serine protease inhibitor that blocks local kinin formation). These results clearly show that there is a synergistic effect on NO formation when amlodipine is combined with ACE inhibition. Our data suggest that kinin-mediated coronary NO production may contribute importantly to the beneficial therapeutic action of ACE inhibitors, especially in combination with amlodipine in the treatment of heart disease.

Ankle Edema Formation during Treatment with the Calcium Channel Blockers Lacidipine and Amlodipine: A Single-centre Study

All studies suggesting a lower incidence of edema on lacidipine than on amlodipine are based on subjective scoring. Therefore, we have compared edema formation on two dihydropyridine calcium channel blockers, using an accurate method for quantitative assessment of foot volume. In a randomized study, we treated 62 patients with essential hypertension for 12 weeks starting with either lacidipine 4 mg o.d. (n = 30) or amlodipine 5 mg o.d. (n = 32). At 6 weeks, the doses were increased to that maximally allowed (lacidipine 6 mg, n = 18; amlodipine 10 mg, n = 12) if trough diastolic blood pressure response was insufficient (>90 mmHg and decrease < 10 mmHg). Edema, scored visually, occurred more frequently (p = 0.02) on amlodipine (15/32) than on lacidipine (6/30); this was confirmed by an increase of foot volume above the 95% upper limit of normal variation in 15 patients on amlodipine and in only five patients on lacidipine (p = 0.01). In the whole group of patients, both the increases of foot volume and the decreases of blood pressure just failed to be significantly different between amlodipine and ]acidipine (foot volume, +3.3+/-1.0% on amlodipine and +1.2+/-0.5% on lacidipine, p = 0.08; mean arterial pressure, -11+/-1% on amlodipine and -8+/-1% on lacidipine, p = 0.052). In patients requiring dose increase, the increase of foot volume on amlodipine was more pronounced (p < 0.05), and the antihypertensive effect was larger (p < 0.05) than on lacidipine. In conclusion, our data show a higher incidence of edema on amlodipine than on lacidipine, which has to be explained at least partly by a comparably higher dose c.q. a larger antihypertensive effect of amlodipine. Other mechanisms might have contributed to these differences and need to be explored.