The pharmacology of losartan and other angiotensin receptor blockers (ARBs) is very important. In a dose of 50 mg/day losartan is an effective antihypertensive. Action manifests early and progresses to peak at 2-4 weeks. Addition of 12.5 mg/day hydrochlorothiazide further enhances the fall in BP. The newer ARBs—valsartan, candesartan, irbesartan and telmisartan have been shown to be as effective antihypertensives as ACE inhibitors, while losartan may be somewhat weaker than high doses of ACE inhibitors. Angiotensin receptor blockers are remarkably free of side effects. Because they do not increase kinin levels, the ACE inhibitor related cough is not encountered. Angioedema, urticaria and taste disturbance are also rare. Though effects of ACE inhibitors and Angiotensin receptor blockers are not identical, the latter have all the metabolic and prognostic advantages of ACE inhibitors.
Several interventional endpoint reduction trials like LIFE (2002), VALUE (outcomes in hypertensive patients with valsartan or amlodipine, 2004), SCOPE (study on cognition and prognosis in the elderly; stroke prevention with candesartan in elderly with isolated systolic hypertension, 2004), JLIGHT (Japanese losartan therapy intended for global renal protection in hypertensive patients, 2004) have attested to the favourable effects of angiotensin receptor blockers on morbidity and mortality in hypertensive patients.
The value of combining angiotensin receptor blockers with ACE inhibitors is discussed in another article.