DIURETIC DRUGS

DIURETIC DRUGS

Drugs that increase the rate or output of urine formation by the kidney are called diuretics. They promote the excretion of electrolytes and water from the body. Diuretics act on tubular function (nephron) and do not affect the glomerular filtration rate in causing diuresis. Diuretics increase the quantity of sodium and chloride ions in the urine and the increased salt excretion is being accompanied by an increased water exeretion to maintain osmotic balance. This action is achieved by director indirect inhibition of the reabsorption of Nations by the kidney tubules. The increased urine flow may also be produced by suppressing the secretion of antidiuretic hormone vasopressin from posterior pituitary. Diuretics are used to treat all types of oedema, i.e. disease associated with abnormal retention of salt and water in extracellular parts of the body. The important diseases associated with oedema are congestive heart failure, premenstrual tension, oedema of pregnancy, renal oedema, cirrhosis with ascites and oedema induced by the administration of adrenocorticotropin (ACTH) and other corticosteroids.

The diuretics used are water and osmotic agents, acidifying salts, xanthine derivatives, mercurials, : α ß- unsaturated ketones, sulphonamides and purines, pyrimidines and related heterocyclic compounds. They are also used, alone or in combination with other antihypertensive agents, in the treatment of raised blood pressure.