hydroklorotiazid

Hydroklorotiazid, commonly known as hydrochlorothiazide, is a thiazide-type diuretic used in the management of hypertension and edema. It is prescribed for essential hypertension and edema associated with congestive heart failure, liver cirrhosis, and certain kidney disorders. It can also be used to reduce urinary calcium excretion in idiopathic hypercalciuria and as part of combination therapy for high blood pressure.

Mechanism of action: Hydrochlorothiazide acts on the distal convoluted tubule of the nephron, inhibiting the Na+/Cl- cotransporter. This decreases reabsorption of sodium and chloride, increases diuresis, and lowers blood volume and blood pressure. Long-term antihypertensive effects are thought to involve changes in vascular resistance.

Pharmacokinetics: It is administered orally and is well absorbed, with an average bioavailability around 60–70%. It is largely excreted unchanged by the kidneys. The plasma half-life is typically in the range of 5–15 hours, supporting once-daily dosing in many patients.

Adverse effects and interactions: Potential electrolyte disturbances include hypokalemia, hyponatremia, and hyperuricemia, which can precipitate gout. Other possible effects include dehydration, hyperglycemia, and photosensitivity. NSAIDs may reduce its diuretic effect; it can interact with other antihypertensives and with potassium-sparing agents or supplements.

History and naming: Hydrochlorothiazide is a member of the thiazide class of diuretics, developed in the mid-20th century and remains widely prescribed. Generic formulations are available under various brand names.