Angiotensin receptor blockers (ARBs) are a cornerstone medication class for hypertension management and are frequently used as first-line or second-line antihypertensive therapy. Their clinical relevance extends beyond blood pressure (BP) reduction; comparative effectiveness in randomized trials also evaluates tolerability, adherence, and the likelihood that patients discontinue treatment due to adverse events. In short-term studies that examine medication regimens for lowering BP, ARB-containing strategies have been associated with a reduced risk of discontinuation because of adverse events, whereas calcium channel blockers (CCBs) and certain multi-drug combinations may show higher discontinuation rates. Understanding why requires a mechanistic and clinical framework grounded in the renin–angiotensin–aldosterone system (RAAS).
Hypertension is a chronic condition characterized by sustained elevation of arterial pressure, driven by a complex interplay of vascular resistance, neurohormonal activation, renal sodium handling, sympathetic activity, and structural vascular changes. RAAS activation is central: renin catalyzes conversion of angiotensinogen to angiotensin I, which is converted by angiotensin-converting enzyme (ACE) to angiotensin II. Angiotensin II binds to the angiotensin type 1 receptor (AT1R), producing vasoconstriction, stimulating aldosterone release, promoting sodium reabsorption, increasing oxidative stress, and contributing to vascular remodeling. ARBs attenuate these effects by selectively blocking AT1R, thereby reducing downstream signaling without directly inhibiting ACE.
A key difference between ARBs and ACE inhibitors is the bradykinin pathway. ACE inhibition increases bradykinin, which can contribute to adverse effects such as cough and, rarely, angioedema. ARBs do not increase bradykinin and therefore have a generally lower incidence of cough and angioedema compared with ACE inhibitors. For many patients, this improved tolerability translates into better persistence with therapy—an outcome particularly important in hypertension because long-term BP control reduces risks of stroke, myocardial infarction, heart failure, and chronic kidney disease.
In the context of short-term trials, discontinuation due to adverse events reflects tolerability during the initiation or early titration phases. Several adverse-event categories can drive discontinuation in antihypertensive therapy: hypotension or dizziness, renal function changes, hyperkalemia, peripheral edema, headache, and gastrointestinal symptoms. ARBs can cause elevations in serum potassium and modest increases in creatinine, especially in patients with chronic kidney disease, diabetes, concomitant use of potassium-sparing diuretics, or in settings of reduced effective circulating volume. However, these effects are often manageable with dose adjustment and monitoring. Clinicians typically monitor renal function and potassium after initiation and during titration, and these practices may contribute to a lower observed discontinuation risk when regimen tolerability is favorable.
By contrast, certain CCBs—particularly dihydropyridines—are well known to cause peripheral edema through preferential arteriolar vasodilation without equivalent venous dilation. Peripheral edema is dose-related and can be clinically significant enough to lead to treatment stopping for some patients. Additionally, some combination regimens may increase the frequency or burden of adverse effects by aggregating side effects from multiple drug classes, thereby elevating the probability of early discontinuation.
Treatment persistence in hypertension is influenced not only by pharmacology but also by baseline risk, comorbidities, and patient factors. Age, frailty, polypharmacy, renal impairment, electrolyte disturbances, and adherence behaviors all modify tolerability and willingness to continue medication. ARBs tend to be effective across diverse patient populations, including those with diabetes and albuminuric chronic kidney disease, where RAAS blockade can reduce intraglomerular pressure and slow progression of renal injury. Furthermore, ARBs may support cardiovascular protection through reductions in afterload and favorable effects on vascular function. While these benefits accrue over time, early tolerability affects whether patients remain on therapy long enough for long-term risk reduction.
From an evidence interpretation standpoint, the reported association between ARB-containing regimens and lower discontinuation due to adverse events should be understood as a short-term signal. Discontinuation in early trial periods can be driven by acute adverse effects and initial tolerability. Longer-term outcomes may differ, and absolute risks depend on dosing strategies, titration speed, and monitoring intensity. Still, these comparative tolerability findings are clinically meaningful because they can inform initial drug selection, especially for patients at higher risk for side effects or those who have previously discontinued antihypertensives.
Practical prescribing involves selecting an ARB or combination regimen aligned with patient risk profiles, initiating at an appropriate dose, and performing baseline laboratory evaluation where indicated. Monitoring for hyperkalemia and changes in kidney function is essential, and patient counseling should address symptoms of hypotension, dizziness, and volume depletion. Dose titration should be individualized to achieve BP targets while minimizing adverse events. If adverse effects occur, clinicians may adjust the dose, switch classes, or modify the combination strategy.
Ultimately, ARBs represent an evidence-supported RAAS blockade approach that balances potent antihypertensive efficacy with a tolerability profile that, in comparative short-term trial data, may reduce the likelihood of discontinuation due to adverse events. Optimizing antihypertensive therapy therefore requires integrating mechanistic rationale, patient-specific risk factors, and trial-derived tolerability endpoints to improve persistence and sustained BP control.
Source: Medscape
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