Losartan er en oralt aktiv angiotensin II (Ang- II) - receptorantagonist, der påvirker AT1- receptorundertypen.
Losartan is an orally active angiotensin II (Ang- II) receptor antagonist acting on the AT1 receptor subtype, thus blocking the effect of Ang-II in the renin angiotensin system (RAS) cascade.