diureticsare

Diuretics are medications that promote diuresis, increasing the excretion of water and electrolytes by the kidneys. They are commonly used to treat hypertension and edema associated with heart failure, liver cirrhosis, and certain kidney diseases. They also have roles in glaucoma management and in maintaining fluid balance during various medical treatments.

Diuretics are grouped by their site of action in the nephron and their mechanism. Thiazide diuretics inhibit the Na-Cl symporter in the distal convoluted tubule, producing modest diuresis and potassium loss. Loop diuretics block the Na-K-2Cl cotransporter in the thick ascending limb, yielding strong diuresis with greater electrolyte disturbance. Potassium-sparing diuretics include aldosterone antagonists such as spironolactone and eplerenone, which reduce potassium loss, and ENaC blockers like amiloride and triamterene, which minimize potassium depletion. Carbonic anhydrase inhibitors (acetazolamide) cause bicarbonate loss in the proximal tubule, with milder diuresis and possible metabolic acidosis. Osmotic diuretics (mannitol) raise the osmolarity of the filtrate, producing diuresis in specific indications such as elevated intracranial pressure.

Clinical use is guided by the desired degree of diuresis and the patient’s kidney function and electrolyte status. Common adverse effects include electrolyte imbalances (hypokalemia with thiazides and loop diuretics; hyperkalemia with potassium-sparing agents), dehydration, and hypotension. Thiazides and loop diuretics can raise uric acid and precipitate gout. Drug interactions with NSAIDs, lithium, and certain antihypertensives can affect efficacy and safety.