Angiotensin II Receptor Blockers (Losartan, Telmisartan)
Other
In plain English
ARBs are blood-pressure pills that relax blood vessels by blocking a hormone (angiotensin II) that narrows them. They also protect the kidneys in diabetes and help in heart failure, and they are a common alternative for people who get a cough from ACE inhibitors. They must not be used in pregnancy.
The science
Losartan and telmisartan selectively block the angiotensin II type 1 (AT1) receptor, producing vasodilation, reduced aldosterone secretion, and lower blood pressure without affecting bradykinin (hence less cough than ACE inhibitors). In the LIFE trial (9,193 hypertensive patients with LV hypertrophy), losartan-based therapy reduced the composite of cardiovascular death, stroke, or MI versus atenolol, driven largely by stroke reduction; ARBs are guideline options for hypertension, heart failure, and diabetic/proteinuric kidney disease.
References
- Dahlof B et al., cardiovascular morbidity/mortality with losartan vs atenolol (LIFE), Lancet 2002
- Patel P & Launico MV, Angiotensin II Receptor Blockers (ARB), StatPearls (NCBI Bookshelf) 2025