Diuretics

By Anushka Dubey Student Pharm D 3rd year.
Definition of diuretics, complete classification of diuretics, high celling/ loop diuretics , thiazide diuretics, mechanism of action, images of various parts of nephron, anatomy of kidney, structure of nephrons, site of action of drugs at nephron, indication, side effects, uses and examples of the drugs.

1. Diuretics By:-anushka dubey

2. Defination These are drugs which cause a net loss of sodium and water in the urine. all the diuretics increases the excretion of the water from the body.

3. ANATOMY OF KIDNEY

4. NEPHRON

5. MOVEMENT OF ELECTROLYTES

6. MAJOR SITES FOR REABSORPTION Site 1 :- Proximal Convoluted Tubule (PCT). Site 2 :- Ascending Loop of Henle. Site 3 :- Distal Convoluted Tubule (DCT ). Site 4 :- Late Distal Tubule and Collecting Duct.

7. SITE OF ACTION OF DIURETIC DRUGS

8. MAJOR CLASSIFICATION 1.) High efficacy diuretics. 2.) Medium efficacy diuretics. 3.) Low efficacy diuretics.

9. Classification  There are classified into 6 types:- 1.) Loop diuretics/High ceiling. 2.) Thiazides 3.) Carbonic anhydrase inhibitors. 4.) Potassium-sparing diuretics. 5.) Osmatic diuretics. 6.) Low ceiling diuretics.

10. High Efficacy Diuretics  Inhibitors of sodium , potassium and chlorides co-transport.  Examples :- 1.) Furosemide. 2.) Torasemide. 3.) Ethacrynic acid.

11. Medium Efficacy Diuretics  Inhibitors of sodium and calcium symport system.  Examples :- 1.) Benzthiazide. 2.) Metolazone.

12. Low Efficacy Diuretics  It is further divided into 4 sub-class :- (a) CA inhibitors. Example:- Acetazolamide. (b) Potassium-sparing diuretics. Example:- Spironolactone , Amiloride. (c) Osmotic diuretics. Example:- Glycerol, Mannitol. (d) Xanthines Example:- Theophlline .

13. Mechanism of diuretic drugs

14. MOA on LOOP

15. LOOP DIURETICS 1.) Site of action :- On Ascending loop of Henle. 2.) Mechanism :- Inhibits the symporter of Na +/ K + /2Cl - 3.) Urine :- Increased excretion of all ions (sodium, potassium, chloride, magnesium, calcium as well as bicarbonates.

16. Indications & Side effects of loop diuretics Loop Diuretics :- Large volume diuresis. Isotonic urine (compared to plasma). Indications :- Edema Congestive heart failure. Acute pulmonary edema. Cirrhosis. Hypertension. Hypercalcemia. Forced diuresis. Side Effects :- Excess volume depletion. Hypokalemia. Hypocalcemia. Hypomagnesemia. Ototoxicity.

17. Thiazide  Act in the distal tubule.  I nhibits reabsorption of sodium and potassium.  S timulate the reabsorption of calcium.  L oss of water as urine.  Adverse effect :- hyperglycemia, hyperlipidemia, Hypotension, Electrolyte imbalance and Hypersensitivity.

18. MOA of DISTAL TUBULE

19. Potassium-Sparing diuretics  The potassium is retained inside the body which prevents the loss of potassium in the urine. ◦ Aldosterone joins the sodium channels in the cells of collecting duct and lately to the distal tubule in the nephron. ◦ But spironolactone blocks the entry of aldosterone into the cells which prevents the reabsorption of sodium.  Mechanism of the drug :- Spironolactone ◦ Binds with the aldosterone receptor that prevents the hormone from binding to the receptor. ◦ This binding is competitive.

20. Osmotic diuretics  Rise in the osmotic pressure of the plasma which draws water out from the tissue and produces the osmotic diuresis.  S odium excretion does not get effected.  The compounds are filtered by glomerulus but can not be reabsorbed.  This osmotic balance prevents the loss of water in the urine.

21. CARBONIC ANHYDRASE INHIBITORS  CA Inhibitors inhibits the enzyme that is present in the proximal tubule of the nephron.  This inhibition leads to retention of several electrolytes like bicarbonates, magnesium, etc.  Sodium reabsorption is prevented or decreased in the cell.

22. Medicinal Uses  Diuretics are used to treat:- 1.) Heart failure. 2.) Liver cirrhosis. 3.) Hypertension. 4.) Certain kidney diseases. 5.) Cerebral edema. 6.) Reduction of intracranial pressure. 7.) Reduction of certain toxins. 8.) Hypercalciuria.

23. USES AND SIDE EFFECTS OF DIURETICS

24. REFERENCE 1.) Textbook of Pharmacology. 2.) Book of Medicinal Chemistry. 3.) Medical book of Pharmacotherapeutics.