Emerging insights in the first-step use of antihypertensive combination therapy

Combination therapy in hypertension: An update

Meticulous control of blood pressure is required in patients with hypertension to produce the maximum reduction in clinical cardiovascular end points, especially in patients with comorbidities like diabetes mellitus where more aggressive blood pressure lowering might be beneficial. Recent clinical trials suggest that the approach of using monotherapy for the control of hypertension is not likely to be successful in most patients. Combination therapy may be theoretically favored by the fact that multiple factors contribute to hypertension, and achieving control of blood pressure with single agent acting through one particular mechanism may not be possible. Regimens can either be fixed dose combinations or drugs added sequentially one after other. Combining the drugs makes them available in a convenient dosing format, lower the dose of individual component, thus, reducing the side effects and improving compliance. Classes of antihypertensive agents which have been commonly used are angiotensin receptor blockers, thiazide diuretics, beta and alpha blockers, calcium antagonists and angiotensin-converting enzyme inhibitors. Thiazide diuretics and calcium channel blockers are effective, as well as combinations that include renin-angiotensin-aldosterone system blockers, in reducing BP. The majority of currently available fixed-dose combinations are diuretic-based. Combinations may be individualized according to the presence of comorbidities like diabetes mellitus, chronic renal failure, heart failure, thyroid disorders and for special population groups like elderly and pregnant females.

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.