Diuretics

Question 1

Where is the site of action of :
Loop diuretics
Thiazide diuretics
Carbonic anhydrase inhibitors
Potassium sparing diuretics

Answer 1

Ascending loop of henle
Distal and connecting tubules
Proximal tubule
Collecting tubule

Question 2

What are the main actions of diuretics

Answer 2

1-Inhibiting sodium reabsorption and enhancing sodium and water in urine(loop)
2_ inhibiting sodium reabsorption and chloride(thiazide)
3-blocking the exchange of sodium with potassium resulting in excretion od sodium but little loss of potassium(potassium sparing diuretic)

Question 3

T or F
Loop diuretics are the most used diuretics

Answer 3

False
They are the most effective leading to excretion of 20% of salt and water (normal reabsorption of the transporter)

Question 4

Mode of action of loop diuretics

Answer 4

Inhibit sodium potassium chloride cotransporter in the ascending loop

Question 5

What ions will be excreted more under the effect of loop diuretics

Answer 5

Na+
K+
Cl-
Ca2+ (ad l Na+ taarebn)

Question 6

Whats the other mode of action of loop diuretics

Answer 6

Induce renal synthesis of prostaglandins which contribute to increase in renal blood flow and redistribution of renal cortical blood flow

Question 7

List the names of loop diuretics
Derivative of?
MOA
Side effects if present

Answer 7

Bumetanide-furosemide: sulfonamide derivative, orally or IV
Ethacrynic acid: not sulfonamide derivative (when patient is allergic to sulfonamide) less used because of ototoxicity

Question 8

For what loop diuretics are used for:
1-
2-
3-

Answer 8

Pulmonary edema (vasodilation when administered Iv)
Chronic congestive heart failure( to minimize venous and pulmonary congestion)
Hypertension

Question 9

Thiazide diuretics:
Low or high ceiling diuretic?
Mode of action
Location of action
Efficacy?

Answer 9

Low (high for loop diuretics)
Inhibit Na+ and Cl- reabsorption from the transporter at the distal portion
This transporter usually reabsorb 5% only (low efficacy)

Question 10

Ions with increased excretion and the other with decreased under the effect of thiazide

Answer 10

Na+ and K+ increased excretion and cl-
Decreased excretion : Ca2+

Question 11

Uses of thiazide diuretics
1-
2-
3-

Answer 11

Hypertension
Edema associated eith heart failure
Nephrolithiasis (kidney stones) with hypercalciuria (because thiazides decrease Ca in urine)

Question 12

Thiazide like analogs like—– at low levels show—–
Others included in this class like—

Answer 12

Indapamine(fludex LP)
Low hypertensive action
Hydrochlorothiazide (Esidrex)

Question 13

Carbonic anhydrase inhibitors:
Mode of action
Location
Effect
Name of drugs included
Ofher usage of the drug
Efficacy

Answer 13

Inhibit carbonic anhydrase which lead to less sodium bicarbonate absorption at the proximal tubule
Decrease sodium potass and bicarbonates reab
Acetazolamide(Diamox) ; used in ophtalmo for tx of glaucoma
Much less efficacious than loop and thiazide

Question 14

Ions increased in urine
Ions decreased

Answer 14

Na+
K+
HCO3-
No ions decreased in urine

Question 15

Mechanism of action of CAI on slide

Question 16

Potassium sparing diuretics include —– and ——

Answer 16

Aldosterone antagonist (spironolactone aka aldactone) and sodium channels blockers

Question 17

ENaC inhibitors include—- and —–
Mode of action:
Location of action:
Benefits:
Adverse effects:

Answer 17

Amiloride
Triamterene
Late Distal and collecting tubule
Prevent hypokalemia caused by thiazide and loop diuretics
Hyperkalmeia is the main adverse effect

Question 18

Ions incr and decreased after usage of k sparing diuretics

Answer 18

Decreased K+
Na+ increased

Question 19

Osmotic diuretics:
Mode of action:
Examples:

Answer 19

Inhibit reabsorption of water and Na+
Increasing the osmolarity of blood and renal filtrate
Glycerol and mannitol

Question 20

Usages of osmotic diuretics

Answer 20

Tx for IC pressure

Question 21

List the adverse effects of :
Thiazide
Loop
K+ sparing

Answer 21

Thiazide: hyperglycemia,hypokalemia,hyponatremia,hyperuricemia
Loop: hypokalemia hyponatrmia, metabolic alkalosis, hypomagnesemia,hyperuricemia and dehydration
K+sparing; peptic ulcer, metabolic acidosis hyperkalemia,gynecomastia and menstrual irregularities

Question 22

List the drug interactions of:
Thiazide:
Loop:
K+ sparing

Answer 22

All with NSAIDs have lower drug efficacy
Thiazide: beta blockers potentiate hyperglycemia
Corticosteroids enhance hypokalemia
Loop: Corticosteroids enhance hypokalemia, aminoglycosides cause nephrotoxicity