18. Cardiology - Diuretics INCOMPLETE

Question 1

Give an example of a thiazide diuretic.

Answer 1

Bendroflumethiazide.

Question 2

What is the naming rule of loop diuretics? Give an example.

Answer 2

-ide. Furosemide, bumetanide.

Question 3

What is the naming rule of potassium-sparing diuretics? Give an example.

Answer 3

-one. Spironolactone (also amiloride).

Question 4

Give an example of a carbonic anhydrase inhibitor.

Answer 4

Acetazolamide.

Question 5

Give an example of an osmotic diuretic.

Answer 5

Mannitol.

Question 6

What are the five functional zones of the nephron?

Answer 6

Proximal convoluted tubule, descending loop of Henle, ascending loop of Henle, distal convoluted tubule, collecting tubule and duct.

Question 7

What is reabsorbed in the PCT?

Answer 7

Glucose, amino acids, Na+, K+, H2O.

Question 8

What is reabsorbed in the ascending loop of Henle?

Answer 8

Na+, K+, Cl-.

Question 9

What is reabsorbed in the distal convoluted tubule?

Answer 9

Cl-, Na+.

Question 10

What is secreted in the collecting tubule and duct?

Answer 10

H+ and K+.

Question 11

What is reabsorbed in the collecting tubule and duct?

Answer 11

H2O.

Question 12

Where do thiazide diuretics act?

Answer 12

In the distal convoluted tubule.

Question 13

Why are thiazide diuretics sometimes called “low ceiling diuretics”?

Answer 13

Because increasing the dose above normal therapeutic doses doesn’t promote further diuretic response.

Question 14

What is the mechanism of action of thiazides?

Answer 14

Act in cortical region of ascending loop of Henle and distal convoluted tubule to inhibit Na+/Cl- cotransporter on luminal membrane of tubule and reduce Na+ reabsorption. So increased Na+ and Cl- in tubular fluid.

Question 15

What can reduce the efficacy of thiazides?

Answer 15

Decreased renal function, e.g. from concomitant use of NSAIDs.

Question 16

What is the impact of urinary excretion of Ca2+, K+, Na+ and volume of urine due to thiazide use?

Answer 16

Decreased Ca2+ excretion, increased excretion of Na+, K+, and volume of urine.

Question 17

What are the therapeutic uses of thiazide diuretics?

Answer 17

Hypertension, heart failure, hypercalcuria, diabetes insipidus.

Question 18

What are the five main ADRs of thiazide diuretics?

Answer 18

Hypokalaemia, hypuricaemia, hypotension, hyponatraemia, hypercalcaemia.

Question 19

How can hypokalaemia be avoided in thiazide diuretic use?

Answer 19

Supplemented by dietary measures or supplements. If RAAS –> aldosterone release –> worsened hypokalaemia, then spironolactone or other K+ sparing diuretics should be used too.

Question 20

How do thiazide diuretics cause hyponatraemia?

Answer 20

Elevated ADH from hypovolaemia.

Question 21

How do thiazide diuretics cause hyperuricaemia?

Answer 21

Increased uric acid by decreasing amount of acid excreted by organic acid secretory system.

Question 22

In what scenario is metolazone (thiazide-like diuretic) considered over thiazide diuretics?

Answer 22

Advanced renal failure, it can still cause Na+ excretion.

Question 23

GOT TO IV. LOOP OR HIGH-CEILING DIURETICS

Answer 23

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