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

Rationale for the use of a fixed-dose combination in the management of hypertension: efficacy and tolerability of lercanidipine/enalapril

Hypertension, a significant factor in the development of cerebrovascular disorders, heart disease and renal failure, is a common disorder worldwide. Despite the availability of a wide range of antihypertensive agents, almost two-thirds of hypertensive patients have poorly controlled blood pressure (BP). Numerous clinical trials have shown that most patients require at least two antihypertensive agents to achieve adequate BP control and associated significant reductions in cardiovascular morbidity and mortality. Combination therapy using two drugs with different, complementary mechanisms of action achieves better efficacy and tolerability outcomes than treatment with either component drug alone. When such a combination is administered as a fixed-dose formulation, other benefits, such as improved compliance and potentially lower costs, are also likely. The good efficacy and tolerability of the combination of a calcium channel antagonist and an angiotensin-converting enzyme inhibitor is well established, and this combination is recommended by European Society of Hypertension/European Society of Cardiology guidelines as a first choice in high-risk hypertensive patients, including those with type 2 diabetes mellitus. Lercanidipine/enalapril is a promising example of a fixed-dose combination of these drug classes. In clinical trials in hypertensive patients, including those with type 2 diabetes, lercanidipine/enalapril improved BP to a greater extent than either drug as monotherapy (in patients who were previous non-responders to lercanidipine or enalapril) or the combination of lercanidipine/hydrochlorothiazide, and was equally well tolerated. Further studies are required to evaluate the cardiovascular protective effects of lercanidipine/enalapril.

Manidipine treatment in patients with albuminuria not sufficiently reduced with renin-angiotensin system blockers

Microalbuminuria is an issue of great concern in hypertensive patients owing to its close relation with cardiovascular morbidity and mortality. Treatment should aim to reduce microalbuminuria to the normal range. Drugs that block the renin-angiotensin system have specific antiproteinuric properties, but more than one drug is needed to achieve blood pressure control in most cases. The aim of this study was to compare the effects of adding manidipine to the treatment of patients with essential hypertension and persistent albuminuria, despite full-dose treatment with a renin-angiotensin system blocker on urinary albumin excretion (UAE) after 24 weeks of therapy. Patients with diabetes and renal insufficiency were excluded. At baseline, blood pressure and UAE were 155.1 +/- 12/87.76 +/- 11 mmHg and 293.19 +/- 285 mg/g, respectively. At study end, blood pressure was 137.1 +/- 13.1/77.24 +/- 10.4 mmHg (p < 0.001 vs baseline). UAE was reduced by 45% to 161.52 +/- 163 mg/g (p < 0.001 vs baseline). No correlations were found between systolic blood pressure reduction and UAE reduction (Pearson's R = -0.034; p = not significant) nor between estimated glomerular filtration rate and UAE reduction (Pearson's R = -0.0056; p = not significant). No patient withdrew from the study owing to side effects. In conclusion, treatment with manidipine resulted in a large reduction in UAE rates, and this reduction appeared to be independent of the degree of blood pressure reduction or changes in estimated glomerular filtration rate. Our data supports the added value of manidipine in the treatment of patients with hypertension and microalbuminuria.

Effectiveness and tolerability of fixed-dose combination enalapril plus nitrendipine in hypertensive patients: results of the 3-month observational, post-marketing, multicentre, prospective CENIT study

BACKGROUND AND OBJECTIVE

Monotherapy with any class of antihypertensive drug effectively controls blood pressure (BP) in only about 50% of patients. Consequently, the majority of patients with hypertension require combined therapy with two or more medications. This study aimed to evaluate the effectiveness (systolic BP [SBP]/diastolic BP [DBP] control) and tolerability of the fixed-dose combination enalapril/nitrendipine 10 mg/20 mg administered as a single daily dose in hypertensive patients.

METHODS

This was a post-authorization, multicentre, prospective, observational study conducted in primary care with a 3-month follow-up. Patients throughout Spain with uncontrolled hypertension (> or =140/90 mmHg for patients without diabetes mellitus, or > or =130/85 mmHg for patients with diabetes) on monotherapy or with any combination other than enalapril + nitrendipine, or who were unable to tolerate their previous antihypertensive therapy, were recruited. Change from previous to study treatment was according to usual clinical practice. BP was measured once after 5 minutes of rest in the sitting position. Therapeutic response was defined as follows: 'controlled' meant controlled BP (<140/90 mmHg for nondiabetic patients, or <130/85 mmHg for diabetic patients); 'response' meant controlled BP, or a decrease in SBP of > or =20 mmHg and in DBP of > or =10 mmHg. The main laboratory test parameters were documented at baseline and after 3 months. Patients aged >65 years, with diabetes, with isolated systolic hypertension (ISH; SBP > or =140 mmHg for patients without diabetes, SBP > or =130 mmHg for patients with diabetes) and who were obese (body mass index [BMI] > or =30 kg/m2) were analysed separately.

RESULTS

Of 6537 patients included, 5010 and 6354 patients were assessed in effectiveness and tolerability analyses, respectively. In the tolerability analysis population, there were 3023 men (47.6%) and 3321 women (52.4%). The mean (+/- SD) age of the tolerability analysis group was 62.8 (+/- 10.7) years. A total of 71.1% of the patients presented at least one clinical cardiovascular risk factor other than hypertension, with the most frequent being dyslipidaemia (42.3%), obesity (29.2%) and diabetes (23.9%). After 3 months of treatment, SBP and DBP showed mean (+/- SD) decreases of 26.5 (+/- 14.4) mmHg and 14.9 (+/- 9.0) mmHg, respectively, and 73.0% of patients responded to treatment while 40.9% achieved BP control (70.8%/36.1% in 2658 patients aged >65 years; 61.7%/46.8% in 1521 patients with diabetes; 55.3%/44.2% in 731 patients with ISH; 72.0%/36.4% in 1762 obese patients). Adverse events were reported in 10.8% of patients (n = 689). During the follow-up period, ten patients died and seven patients had serious adverse events; in no case was a causal relationship attributed to the study product.

CONCLUSIONS

The rate of SBP/DBP control achieved demonstrates the effectiveness of the fixed-dose enalapril/nitrendipine 10 mg/20 mg combination administered as a single daily dose in patients with essential hypertension not adequately controlled with monotherapy or with any combination other than enalapril + nitrendipine. The proportion and type of adverse events reported were as expected and have already been described for both components of the enalapril/nitrendipine 10 mg/20 mg combination. These results confirm the effectiveness of a strategy based on a fixed-dose enalapril/nitrendipine 10 mg/20 mg combination in reducing BP and achieving BP control goals.

Complementary mechanisms of angiotensin receptor blockers and calcium channel blockers in managing hypertension

Hypertension affects approximately 73 million individuals in the United States. Clinical studies have shown that antihypertensive therapy can reduce blood pressure (BP) and the risk of cardiovascular events. However, the majority of patients with hypertension do not achieve the recommended BP goal of < 140/90 mm Hg (or < 130/80 mm Hg for patients with diabetes) with antihypertensive monotherapy, and require therapy with 2 or more antihypertensive agents. Combination therapy utilizes antihypertensive agents from different drug classes, which act via distinct pharmacologic mechanisms to improve overall efficacy and tolerability. Although combination therapy is superior to monotherapy in achieving BP goals across the entire spectrum of hypertension, the proportion of patients achieving the recommended BP goal can be further improved by the use of new antihypertensive drug combinations. The beneficial antihypertensive characteristics of both angiotensin receptor blockers and calcium channel blockers suggest that combining these classes may result in a highly efficacious antihypertensive therapy with regard to both activity and safety when used as a fixed-dose combination. In particular, a fixed-dose combination of olmesartan medoxomil plus amlodipine besylate has been demonstrated to be an efficacious antihypertensive combination due in part to the benefits associated with each of these agents within their respective drug classes.

Add-on manidipine versus amlodipine in diabetic patients with hypertension and microalbuminuria: the AMANDHA study

The aim of this study was to compare the efficacy and safety of adding manidipine 20 mg versus amlodipine 10 mg to the treatment of diabetic patients with uncontrolled hypertension and microalbuminuria despite full-dose treatment with a renin-angiotensin system blocker for at least 6 months. Patients were randomized to receive manidipine (n = 61) or amlodipine (n = 30) in a 2:1 ratio for 6 months and monitored for microalbuminuria for an additional extension phase of 18 months. Manidipine and amlodipine decreased blood pressure values to a similar extent. Urinary albumin excretion was reduced by 65.5% with manidipine versus 20% with amlodipine (p < 0.01) at 6 months and 62.7 versus 16.6% (p < 0.01) at the end of the extension phase. Manidipine was better tolerated than amlodipine. Thus, the addition of manidipine, but not amlodipine, resulted in a large reduction in the urinary albumin excretion rate despite similar blood pressure reductions.