Presentation on theme: "Diuretics and Dehydrants. §1 Diuretics Abnormalities in fluid volume and electrolyte composition are common and important clinical problems. Drugs that."— Presentation transcript:
Abnormalities in fluid volume and electrolyte composition are common and important clinical problems. Drugs that block the transport functions of the renal tubules are valuable clinical tools in the treatment of these disorders. It was not until 1957 that a practical and powerful diuretic agent (chlorothiazide) became available for widespread use. Technically, the term "diuresis" signifies an increase in urine volume, while "natriuresis" denotes an increase in renal sodium excretion. Because natriuretic drugs almost always also increase water excretion, they are usually called diuretics.
Most diuretics act upon a single anatomic segment of the nephron. Because these segments have distinctive transport functions, the first section of this chapter is devoted to a review of those features of renal tubule physiology that are relevant to diuretic action.
Common diuretics exert effects on specific membrane transport proteins in renal tubular epithelial cells (loop diuretics, thiazides, amiloride, and triamterene) exert osmotic effects that prevent water reabsorption (mannitol) exert effects by inhibiting enzymes (acetazolamide) exert effects by interfering with hormone receptors in renal epithelial cells (spironolactone)