Losium-H Tablet contains a combination of Losartan 50 mg and Hydrochlorothiazide 12.5 mg, indicated for the management of hypertension. Losartan is an angiotensin II receptor antagonist that selectively blocks the binding of angiotensin II to the AT1 receptor, thereby inhibiting vasoconstriction and aldosterone secretion, leading to vasodilation and reduction in blood pressure. Hydrochlorothiazide is a thiazide diuretic that promotes diuresis by inhibiting sodium reabsorption in the distal convoluted tubules of the kidneys, resulting in decreased plasma volume and peripheral vascular resistance. The synergistic action of these two agents provides effective blood pressure control, reducing the risk of cardiovascular events such as stroke and myocardial infarction. Losium-H is typically prescribed when monotherapy with either agent is insufficient to achieve target blood pressure. It is contraindicated in patients with hypersensitivity to either component, anuria, or severe renal impairment. Caution is advised in patients with electrolyte imbalance, diabetes mellitus, or hepatic dysfunction. Regular monitoring of renal function, electrolytes, and blood pressure is recommended during therapy. Adverse effects may include dizziness, hypotension, hyperkalemia, and electrolyte disturbances. Losium-H should be used under medical supervision with adherence to prescribed dosage and lifestyle modifications for optimal therapeutic outcomes.