D. Pharm Pharmacology & Toxicology, Drugs Acting on The Kidney( Chapter-10)

 Chapter-10

Drugs Acting on The Kidney 

DIURETICS

       Diuretics are drugs which increase the flow of urine. These drugs are mainly used for the relief of edema. Also they are useful for the elimination of toxic products through urine.

Classification of diuretics

 1. High efficacy diuretics / Loop Diuretics / High ceiling diuretics: 

 A. Sulphamoyl derivatives: 

              Furosemide, 

              Bumetanide, 

              Piretanide. 

B. Phenoxyacetic acid derivatives: 

             Ethacrynic acid 

C. Organomercurials:

             Mersalyl

 MOA: Inhibit Na*-K*-2Cl Cotransport

2. Medium efficacy diuretics:

 A. Benzothiadiazines: (Thiazides) Chlorthiazide, Hydrochlorthiazide, Benzthiazide, Flumethiazide, Clopamide 

B. Thiazide like related heterocyclics: Chlorthalidone, Xipamide, Metolazone, Indpamide

3. Weak / Adjunctive diuretics: 

A. Carbonic anhydrase inhibitors: Acetazolamide, Ethoxazolamide 

B. Potassium sparing diuretics: 

(i) Aldosterone antagonist: Spironolactone 

(ii) Directly acting: Triamterene and Amiloride

 (iii) Osmotic diuretics: Mannitol, Isosorbbide, Urea & Glycerol

 (iv) Xanthines: Theophylline

    Loop diuretics  

Site of action=  Site II    

 MOA =Inhibit Na*-K*-2CI Cotransport

Side effect= Hypokalemia, Hyponatremia, Hyperglycemia, hyperuricemia, Ototoxicity & Hepatotoxicity

Uses= Pulmonary oedema, Hypertension (For short term treatment), Food & drug poisoning, renal failure.

Thiazide diuretics

Site of action=  Site III 

MOA=Inhibit Na* -Cl transport

 Side effect= Hypokalemia, Hyperglycemia, Hyperuricemia, hypercalcemia, alkalosis.

Uses=Hypertension (For long term)

 Spiranolactone

 Site of action=   Site IV

 MOA=inhibit Aldosterone induced protein 

Side effect=Hyperkalemia, gynacomastia, impotence, hirsutism

Uses=

Amiloride & Triamterene

Site of action=  Site IV

 MOA= Inhibit Luminal sodium channel

Side effect=Hyperkalemia

 Osmotic diuretics

Site of action= Primarily PT 

MOA= increase osmotic pressure of renal tube 

Side effect=Headache (Mannitol) 

Uses=Cerebral oedema, Food & drug poisoning, Acute congestive glaucoma.

Carbonic anhydrase Inhibitor

 Site of action=  PT

 MOA=  Inhibit carbonic anhydrase

 Side effect=   Systemic acidosis, Kaliuretic

Uses=Glaucoma, Epilepsy, Acute mountain sickness, Alkalization of urine.

Short Questions & Answers

1.Loop diuretics act by 

(a) Inhibition of Na*-Cl'symport

 (b) Inhibition of Na*-K*-2Cl cotransport 

(c) Inhibition of Na*-K* ATPase 

(d) Inhibition of Na* channel

Answer :Inhibition of Na*-K*-2Cl cotransport 

2 Which of the following is a high ceiling diuretic

 (a) Furosemide

 (b) Spironolactone

 (c) Acetazolamide 

(d) Thiazide

Answer:Furosemide

3.Diuretics of choice for acute pulmonary edema 

 (a) Loop diuretics

 (b) Thiazides 

(c) Spironolactone 

(d) Mannitol

Answer :Loop diuretics

All types of edema. 

4.Thiazide cause 

 (a) Metabolic alkalosis

 (b) Metabolic acidosis. 

(c) Respiratory alkalosis 

(d) Respiratory acidosis

Answer:Metabolic alkalosis

5.Maximum potassium loss is caused by which diuretics

 (a) Furosemide

 (b) 'Thiazide

 () Acetazolamide

 (d) Spironolactone

Answer:Acetazolamide

6.Diuretic which can be given in mild to moderate hypertension?

 (a) Loop diuretic 

(b) Thiazide diuretic

 (c) Osmotic diuretic

 (d) Potassium sparing diuretic

Answer:Thiazide diuretic

7.Mannitol is not used in

 (a) Acute renal failure

 (b) Pulmonary edema 

(c) Cerebral edema

 (d) All of the above

Answer:Pulmonary edema 

8.ADH acts on

 (a) Proximal convoluted tubule 

(b) Distal convoluted tubule

 (c) Loop of Henle

 (d) Collecting duct

Answer :Collecting duct

9.The diuretic group that does not require access to the tubular lumen to induce diuresis is 

(a) Carbonic anhydrase inhibitor 

(b) Na-Cl symport inhibitor

 (c) Mineralocorticoid antagonist 

(d) Na-K symport inhibitor

Answer:Mineralocorticoid antagonist

10. Which of the following is a mineralocorticoid antagonist

 (a) Spironolactone 

(b) Inamrinone 

(c) Nicorandil 

(d) Ketorolac

Answer:Spironolactone

11.Diuretics that can be used in renal failure is 

(a) Furosemide 

(b) Chlorthiazide 

(c) Mannitol 

(d) Chlorthalidone

Answer:Furosemide

All loop of diuretics. 

12.In diabetes insipidus, diuretic showing paradoxical antidiuretic activity

 (a) Thiazide 

(b) Triamterene 

(c) Spironolactone 

(d) Furosemide

Answer :Thiazide

13.Loop diuretics acts on 

(a) Descending limb

 (b) Thick ascending limb 

(c) Cortical segment

 (d) Collecting duct

Answer :Thick ascending limb

14. Furosemide causes all except 

(a) Hyperuricemia 

(b) Ototoxicity 

© Hypercalcemia

 Hypokalemia

Answer :Hypercalcemia

15. Thiazides cause hypercalcemia by

 (a) Increased Ca absorption 

(b) Increased PTH secretion 

(c) Decreased calcitonin secretion 

(d) Decreased calcium excretion

Answer :Decreased calcium excretion

16. True regarding acetazolamide is

 (a) Irreversible inhibitor of carbonic anhydrase

 (b) Structural resemblance to sulfonamides 

(c) It decreases Na, K, Glucose excretion

 (d) It causes metabolic alkalosis

Answer:Structural resemblance to sulfonamides 

17.Glycerol is an 

(a) Osmotic diuretic

 (b) Purgative 

(c) Antidiabetic 

(d) Antiemetic

Answer :Osmotic diuretic

18.Drug causing gynecomastia is 

(a) Spironolactone

 (b) Rifampicin 

(c) Penicillin

 (d) Bumetanide

Answer :Spironolactone

19.Acetazolamide is 

(a) Competitive and reversible carbonic anhydrase inhibitor 

(b) Non-competitive and reversible carbonic anhydrase inhibitor 

(c) Competitive and irreversible carbonic anhydrase inhibitor 

(d) Non-competitive and irreversible carbonic anhydrase inhibitor

Answer :b

20.Carbonic anhydrase inhibitors

a) Increase the excretion of weekly Basic drugs

 b) Reduce excretion of weakly basic drug

 c) Reduce excretion of weakly acidic drug 

d) No effect on excretion of acidic and basic drug

Answer :b

21. Thiazide diuretics can be used for the treatment of all these conditions except 

a) Idiopathic hypercalciuria with nephrocalcinosis

 b) Hyperlipidaemia

 c) CHF 

d) Hypertension

Answer :Hyperlipidaemia

22.Which of the following diuretics is used in the treatment of glaucoma

 a) Acetazolamide 

b) amiloride 

c) Bumetanide 

d) None

23.The renal system does not play a direct role in regulating witch of the following? 

a) Blood solute concentration

 b) Blood temp 

c) Blood pressure 

d) Blood Ph

24.Diuretic acting primarily on thick ascending time of the loop of Henle 

a) Bumetanide 

b) Chlorothiazide 

c) Mannitol 

d) Spironolactone

25.Loop Diuretics act on site II and Inhibited

 a) Na, cl-

 b) Na*K*,cl· 

c) Carbonic anhydrase 

d) Aldosterone

26.Which one is a aldosterone antagonist 

a) Spironolactone

 b) Amiloride 

c) Triamterene 

d) All

27.Which one is a K* sparing diuretics 

a ) Spironolactone 

b) Amiloride 

c) Triamterene 

d) All

28.Steroidal ring present in

 a) Spironolactone

 b) Chlorthalidone

 c) Metolazone

 d) None of above

29.Cerebral Edema is treated with. 

a) Thiazide

 b) Osmotic diuretic

 c) Spironolactone 

d) All

30.Which of the following is a high ceiling diuretic? 

a) Torsemide 

b) Canrenon

 c) Chlortalidone

 d) Thiazide

31.Spironolactone should not be given with

 a) B-Blocker 

b) ACE- inhibitor 

c) Amlodipine 

d) Chlorothiazide

Because Ace inhibitor also produced potassium retaining. But thiazide used which potassium retarded from body.

32. Diuretics that can be used in renal failure is

 a) Metolazone 

b) Furosemide 

c) Mannitol 

d) both a and b

33.Hearing loss occurs rarely which type of diuretic

 a) Potassium sparing diuretic 

b) Thiazide 

c) High ceiling diuretic 

d) Osmotic diuretic

34.Acetazolamide used in 

a) Epilepsy

 b) Glaucoma 

c) Acute mountain sickness 

d) All

35.Most marked Kaliuretic caused with

 a) Acetazolamide 

b) Spironolactone 

c) Furosemide 

d) Ethacrynic acid