It is the first of a new class of drugs to be introduced for clinical use in hypertension. Losartan is an orally active agent that undergoes substantial first-pass metabolism by cytochrome P450 enzymes. It is converted, in part, to an active carboxylic acid metabolite that is responsible for most of the angiotensin II receptor antagonism that follows losartan treatment.
Angiotensin-II is a substance produced in the body which binds to receptors in blood vessels, causing them to tighten. This results in an increase in blood pressure. Losartan prevents the binding of angiotensin-II to these receptors, causing the blood vessels to relax which in turn lowers the blood pressure.
In patients with essential hypertension, once-daily doses of 50 or 100 mg losartan have been shown to effectively lower BP throughout the 24-hour dosing interval and to be well tolerated.
Losartan for high blood pressure
