Question

How does the diuretic works?

Answer 1

Diuretics are those drugs which helps to increase the urine output for a patient who has been administered a diuretic. There are mainly 4 classification of diuretics available, and they works differently on kidneys. The principal mechanism of diuretic is that it acts on various sites of kidneys to diminish sodium re-absorption in the nephron, thereby increasing urinary sodium (expels sodium out of body) and water losses. Sometimes patients are prescribed two diuretics at once in order to maintain efficacy, because certain nephron segment can compensate for altered sodium re-absorption at another nephron segment.

Classification:

1. Loop diuretics

2. Thiazide diuretic

3. Potassium sparing diuretics

4. Carbonic anhydrase inhibitors

Loop diuretic

Inhibits Sodium-potassium-chloride co-transporter in the ascending limb. About 25% of Sodium is re-absorbed at this segment, inhibition of these pump can alters the handling of sodium and water leads to diuresis and natriuresis. This drug also induce renal synthesis of prostaglandin, which contributes to their renal action including increase in renal blood flow and redistribution of renal cortical blood flow.

Thiazide diuretic

Inhibits the sodium-chloride transporter in the distal tubules. This part of nephron reabsorbs about 5% of filtered sodium. The efficiency of these diuretic depends upon the renal prostaglandin production.

Potassium sparing diuretics

This drug helps to increase the blood flow to the distal segment of the distal tubules. This cause more sodium and water to pass into the collecting duct and be excreted in the urine. They are called potassium sparing diuretics because they do not cause hypokalemia as other types of diuretic does.

Carbonic anhydrase inhibitors

Inhibits the transport of bicarbonte out of the proximal convoluted tubule into interstitium, which leads to less sodium reabsorption at this site and therefore greater sodium, bicarbonate and water loss in the urine.