New treatment options in the management of hypertension: appraising the potential role of azilsartan medoxomil

Angiotensin Receptor Blockers in the Management of Hypertension: A Real-World Perspective and Current Recommendations

Hypertension represents a major common cardiovascular risk factor. Optimal control of high blood pressure levels is recommended to reduce the global burden of hypertensive-mediated organ damage and cardiovascular (CV) events. Among the first-line drugs recommended in international guidelines, renin-angiotensin-aldosterone system antagonists [angiotensin converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARBs)] have long represented a rational, effective, and safe anti-hypertensive pharmacological strategy. In fact, current US and European guidelines recommend ACEi and ARBs as a suitable first choice for hypertension treatment together with calcium channel blockers (CCBs) and thiazide diuretics. Different studies have demonstrated that ARBs and ACEi exert a comparable effect in lowering blood pressure levels. However, ARBs are characterized by better pharmacological tolerability. Most importantly, the clinical evidence supports a relevant protective role of ARBs toward the CV and renal damage development, as well as the occurrence of major adverse CV events, in hypertensive patients. Moreover, a neutral metabolic effect has been reported upon ARBs administration, in contrast to other antihypertensive agents, such as beta-blockers and diuretics. These properties highlight the use of ARBs as an excellent pharmacological strategy to manage hypertension and its dangerous consequences. The present review article summarizes the available evidence regarding the beneficial effects and current recommendations of ARBs in hypertension. The specific properties performed by these agents in various clinical subsets are discussed, also including an overview of their implications for the current COVID-19 pandemic.

An evaluation of the latest evidence relating to renin-angiotensin system inhibitors

INTRODUCTION

In the last few years, a number of important clinical trials have been completed that have investigated the inhibition of the renin-angiotensin system. New drugs, focusing on this system, have now emerged as a result.

AREAS COVERED

The authors review the most relevant information available, reported from the last 5 years, pertaining to the most important clinical trials on renin-angiotensin system blockers (ARBs). The authors' data review includes the trials of aliskiren, telmisartan, olmesartan and azilsartan. The authors also review the possible risk of cancer with ARBs.

EXPERT OPINION

The results of ASPIRE and ALTITUDE trials strongly suggested that dual inhibition of aliskiren with either ARBS or angiotensin converting enzyme inhibitors (ACEi) should be avoided. Olmesartan is an effective and safe antihypertensive agent, but special attention should be paid to high-risk patients, such as those with coronary disease, to avoid an excessive reduction in blood pressure. The authors also note that while azilsartan is probably the most potent ARB, there is still a lack of data regarding potential organ damage and the incidence of cardiovascular events. Lastly, recent evidence has shown a lack of a relationship between ARB therapy and the occurrence of cancer.

Azilsartan medoxomil: a review of its use in hypertension

Azilsartan medoxomil (Edarbi®; Ipreziv™) is an orally administered angiotensin II receptor type 1 antagonist (blocker) used in the treatment of adults with essential hypertension. This article reviews data on the clinical efficacy and tolerability of azilsartan medoxomil in adults with essential hypertension and provides a summary of its pharmacological properties. Azilsartan medoxomil is a prodrug that undergoes rapid hydrolysis in the gastrointestinal tract after oral administration to the bioactive moiety azilsartan, before systemic absorption. Azilsartan medoxomil produces antihypertensive effects by selectively blocking the binding of angiotensin II to the angiotensin type 1 (AT(1)) receptor, thereby antagonizing the pressor response activity of angiotensin II. In vitro, azilsartan produced greater and more sustained AT(1) receptor binding/blockade activity than several comparator angiotensin II receptor antagonists. Azilsartan medoxomil reduces blood pressure (BP) in hypertensive adults. In addition, the drug has been shown to have pleiotropic effects (i.e. effects beyond AT(1) receptor blockade). In adults with essential hypertension, azilsartan medoxomil 20, 40 or 80 mg effectively reduced BP over a 24-hour period with once-daily administration in three major, randomized, controlled trials in which the primary endpoints were changes from baseline in 24-hour mean systolic BP (SBP) at week 6 (two trials) or week 24, assessed by ambulatory BP monitoring (ABPM). In the two 6-week trials, azilsartan medoxomil showed dose-dependent efficacy over all evaluated dosages and was more effective than placebo in lowering SBP. At the maximum approved dosage of 80 mg once daily, azilsartan medoxomil was significantly more effective than maximum dosages of olmesartan medoxomil (40 mg once daily) or valsartan (320 mg once daily), based on primary endpoint assessments. Mean reductions in clinic measurements of SBP and diastolic BP (DBP) measurements were also generally greater with azilsartan medoxomil 80 mg once daily than with the comparator drugs in these 6-week studies. Over a longer treatment period of 24 weeks, azilsartan medoxomil showed sustained BP-lowering efficacy, with the reduction in 24-hour mean SBP at week 24 significantly greater with azilsartan medoxomil 40 or 80 mg once daily than with valsartan 320 mg once daily. Mean reductions from baseline in mean clinic SBP and DBP as well as DBP by ABPM were also significantly greater with azilsartan medoxomil 40 or 80 mg once daily than with valsartan. Azilsartan medoxomil was generally well tolerated, with a tolerability profile similar to that of placebo in the 6-week trials. Across the three major trials, headache and dizziness were among the most common adverse events. Overall, rates of treatment discontinuation as a result of adverse events were low in the 6-week and 24-week trials. In conclusion, once-daily azilsartan medoxomil effectively lowers BP in adults with essential hypertension and has shown better antihypertensive efficacy than maximum therapeutic dosages of olmesartan medoxomil or valsartan in major trials of up to 24 weeks' duration. Azilsartan medoxomil is generally well tolerated and the low rates of discontinuation due to adverse events suggest that patients are likely to persist with long-term treatment. Azilsartan medoxomil is therefore a useful and attractive new option for lowering BP in patients with essential hypertension, particularly for those not able to tolerate other antihypertensive drugs. Further studies are required to evaluate the effects of azilsartan medoxomil on cardiovascular morbidity and mortality.