diuretic

1. Promoting the excretion of urine. 2. An agent that increases the amount of urine excreted.

- cardiac d. a d. that acts by increasing function of the heart, and thereby improves renal perfusion.

- direct d. a d. whose primary effect is on renal tubular function.

- indirect d. a d. that acts by increasing cardiac function or by increasing the state of hydration.

- loop d. a class of d. agents ( e.g., furosemide, ethacrynic acid) that act by inhibiting reabsorption of sodium and chloride, not only in the proximal and distal tubules but also in Henle loop.

- mercurial diuretics d. drugs containing organic mercury ( e.g., Mercuhydrin) that promote substantial salt and water loss through the kidney. Among the first potent d. agents used in congestive heart failure, but now obsolescent.

- osmotic diuretics drugs, such as mannitol, which by their osmotic effects retain water during urine formation and thus dilute electrolytes in the urine, making resorption less efficient; they promote the elimination of water and electrolytes in the urine.

- potassium sparing diuretics d. agents that, unlike most diuretics, retain potassium; examples are triamterene and amiloride. Often used together with diuretics that promote the loss of both sodium and potassium. Used in hypertension and in congestive heart failure.

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di·uret·ic .dī-(y)ə-'ret-ik adj tending to increase the excretion of urine

di·uret·i·cal·ly -i-k(ə-)lē adv

diuretic n an agent that increases the excretion of urine

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n.

a drug that increases the volume of urine produced by promoting the excretion of salts and water from the kidney. The main classes of diuretics act by inhibiting the reabsorption of salts and water from the kidney tubules into the bloodstream. Thiazide diuretics (e.g. bendroflumethiazide, chlortalidone) act at the distal convoluted tubules (see nephron), preventing the reabsorption of sodium and potassium. Potassium-sparing diuretics (e.g. amiloride, spironolactone, triamterene) prevent excessive loss of potassium at the distal convoluted tubules, and loop diuretics (e.g. furosemide) prevent reabsorption of sodium and potassium in Henle's loop. Diuretics are used to reduce the oedema due to salt and water retention in disorders of the heart, kidneys, liver, or lungs. Thiazides and potassium-sparing diuretics are also used - in conjunction with other drugs - in the treatment of high blood pressure. Treatment with thiazide and loop diuretics often results in potassium deficiency; this is corrected by simultaneous administration of potassium salts or a potassium-sparing diuretic.

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di·uret·ic (di″u-retґik) [Gr. diourētikos promoting urine] 1. pertaining to or causing diuresis. 2. an agent that promotes diuresis.