Hypertension drug therapy reviewed

This article reviewed the latest questions and research concerning hypertension treatment today, with special emphasis on new generation drugs now becoming available.

Three drug classes; diuretics, calcium channel blockers (CCBs) and renin-angiotensin system (RAS) inhibitors, comprise the mainstay of current hypertension management. The choice of therapy is often determined by patient comorbidities (additional medical conditions) and possible side effects to treatment. Side effects are a main concern due to discontinuation of therapy among many patients (referred to as non-adherence). This review compared both medical benefits and side-effects between commonly employed antihypertensive drugs.

In a comparison between two groups of RAS inhibitors, angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB), 26 trials including more than 100,000 patients were reviewed. The analysis found that both ACE inhibitors and ARBs reduced the risk of serious hypertension complications, such as heart attacks, strokes, kidney failure and mortality, with similar benefit. ACE inhibitors though, showed more side effects such as a cough or the development of angioedema (rapid swelling and edema formation). More recently, a third approach to the inhibition of the RAS has become available through direct renin inhibition, using aliskiren. In clinical studies, aliskiren was found to be as effective as ARBs and ACE inhibitors in the management of hypertension, but showed no additional benefits among diabetic patients, as was once suggested.

Among calcium channel blockers (CCBs), amlodipine is now the most frequently employed agent, and is often used in combination with RAS inhibitors. In clinical practice, the discontinuation rate of CCB treatment is rather high compared to other antihypertensive agents. The main reason for CCB non-adherence is the appearance of peripheral edemas. In recent years, several new CCBs such as lercanidipine, lacidipine, or manidipine have become available, designed to induce less peripheral edema than the classical CCBs. Several studies reviewed have demonstrated a reduced incidence of peripheral edema with the use of these new CCBs. One study showed that the occurrence of peripheral edema was reduced by 50% in patients who switched treatment from amlodipine to lercanidipine. Similarly, in a large survey study, peripheral edema occurred in 18% of patients treated with amlodipine but only in 7% of patients receiving lercanidipine and in 4% of those receiving lacidipine.

Among diuretics, hydrochlorothiazide (HCTZ) remains the most commonly employed agent. Recently however, questions have been raised regarding the place of HCTZ in the management of hypertension. Indeed, analysis of studies tend to suggest that HCTZ is less effective in lowering blood pressure and preventing major complications than RAS blockers or CCBs. In a recent large analysis, including 4683 patients, various diuretics used in the treatment of hypertension were investigated. Analysis showed HCTZ to exhibit the lowest potency among diuretics (meaning that a high dose of the drug is needed to achieve similar blood pressure reductions compared to other diuretics). A second study reviewed found that, even with similar reduction in blood pressure, the rate of cardiovascular events (such as heart attacks or strokes) were higher with HCTZ therapy than with the diuretic chlorthalidone.

This review concluded that all RAS blockers are equally effective in the management of hypertension when used in combination with CCBs or diuretics. The review suggests that new generation CCBs show a lower risk of adverse effects, which may be crucial in achieving long-term patient adherence to therapy. Lastly, the use of the diuretic chlorthalidone seems to be superior to the standard diuretic hydrochlorothiazide, and fixed chlorthalidone – RAS blocker drug combinations should be further examined.

Consult with your physician regarding new antihypertensive medications now becoming available.