Losartan

Losartan is an angiotensin II receptor blocker. Lowers blood pressure by blocking the vasoconstrictor angiotensin II at AT1 receptors.

Mechanism — Direct vasodilation, reduced aldosterone secretion, and renal protection. Mild uric acid lowering (a unique advantage among ARBs). Telmisartan is the more potent insulin-sensitizing alternative.

Use case — Hypertension (typical 50-100 mg/day), diabetic nephropathy, heart failure adjunct. Often first-line in young hypertensives.

Caveats — Don't combine with ACE inhibitors. Hyperkalemia risk in renal insufficiency. Pregnancy contraindicated. Cough side effect of ACE inhibitors is largely absent with ARBs.