Pharmacology 1 - Drugs Acting on the Kidneys 1 (main points)

Question 1

What is the action of diuretics and how do they do this?

Answer 1

Increase urine output through causing a net electrolyte (mainly sodium) and water loss

Question 2

Give 3 examples of conditions that diuretics are used in?

Answer 2

Hypertension
CHF
Hepatic cirrhosis with ascites

Question 3

What are the 2 ways in which diuretics can get into the filtrate?

Answer 3

Glomerular filtration

Secretion via transport process in the proximal tubule

Question 4

Which type of drugs do organic anion transporters in the proximal tubule secrete?

Answer 4

Acidic drugs

Question 5

What type of drugs do organic cation transporters in the proximal tubule secrete?

Answer 5

Basic drugs

Question 6

Are thiazides and loop diuretics acidic or basic?

Answer 6

Acidic

Question 7

Name the diuretic which is a carbonic anhydrase inhibitor?

Answer 7

Acetazolamide

Question 8

What does acetazolamide inhibit?

Answer 8

Reabsorption of HCO3- in the proximal convoluted tubule

Question 9

Does acetazolamide have strong or weak diuretic properties?

Answer 9

Weak

Question 10

Name 3 loop diuretics

Answer 10

Furosemide
Torsemide Bumetanide
Ethacrynic acid

Question 11

What part of the loop of henle do loop diuretics act on?

Answer 11

Ascending limb

Question 12

What do loop diuretics inhibit?

what effect does this have?

Answer 12

Na+/K+/2Cl- cotransporter

Retention of Na+, Cl- and water in the tubule

Question 13

Which type of diuretic are the most efficacious?

Answer 13

Loop diuretics

Question 14

What part of the tubule do thiazide diuretics work on?

Answer 14

Distal convoluted tubule

Question 15

What effect do thiazide diuretics have?

Answer 15

Inhibit the reabsorption of Na+ and Cl- in the distal convoluted tubule resulting in the retention of water in the tubule

Question 16

Name 3 diuretics that act on the collecting duct?

Answer 16

Spironolactone
Amiloride
Triamterene

Question 17

What type of drug is spironolactone?

Answer 17

Aldosterone antagonist (diuretic)

Question 18

What effect does spironolactone have?

Answer 18

Inhibits the aldosterone-mediated reabsorption of Na+ and secretion of K+

Question 19

How do amiloride and triamterene have their effects?

Answer 19

Block Na+ channels in the collecting duct

Question 20

Aside from Na+ and K+ loss, what other ions are increasingly excreted due to loop diuretics?

Answer 20

Ca2+ and Mg2+

Question 21

What property of loop diuretics makes them especially beneficial in pulmonary oedema caused by heart failure?

Answer 21

Possess an additional, indirect, venodilator action

Question 22

Loop diuretics are poorly absorbed from he GI tract - true or false?

Answer 22

False - well absrobed

Question 23

Are loop diuretics effective in severe renal failure?

Answer 23

Yes, they may reduce need for dialysis

Question 24

Why are loop diuretics sometimes used in hypercalcaemia and renal stones?

Answer 24

To increase Ca2+ excretion

Question 25

Name 8 side effects of loop diuretics?

Answer 25

``` Hypokalaemia Metabolic alkalosis Hypovolaemia Hypotension Depletion of calcium and magnesium Hyperglycaemia Hyperuricaemia Hearing loss ```

Question 26

How can hypokalaemia from loop diuretic use be corrected?

Answer 26

Concomitant use of potassium sparing diuretics or potassium supplements

Question 27

Are thiazide diuretics more or less potent than loop diuretics?

Answer 27

Less potent

Question 28

Effect of thiazide diuretics on Ca2+ and Mg2+?

Answer 28

Save these

Question 29

What do thiazide diuretics bind to?

Answer 29

Na+Cl- symporter in distal convoluted tubule

Question 30

Why are thiazide diuretics especially useful in the treatment of hypertension?

Answer 30

Possess an additional indirect vasodilator action

Question 31

What type of diuretics can be used in the treatment of nephrogenic diabetes insidious?

Answer 31

Thiazide

Question 32

Are thiazide or loop diuretics absorbed more quickly after oral administration?

Answer 32

Loop (30-40 mins) vs thiazides (1 to 2 hours)

Question 33

At what time of day are thiazide diuretics normally administered?

Answer 33

Early (to prevent diuresis interfering with sleep)

Question 34

Do thiazide diuretics work in renal failure?

Answer 34

No - ineffective if eGFR less than 30

Question 35

Name of thiazide diuretic used in mild/ moderate heart failure?

Answer 35

Bendroflumethiazide

Question 36

Name of thiazide diuretic often used with a loop?

Answer 36

metolazone

Question 37

Name of a long acting thiazide diuretic?

Answer 37

Xipamide

Question 38

What type of acid base problem do thiazide diuretics cause?

Answer 38

Metabolic alkalosis

Question 39

Effect of thiazide diuretics on K+, Na+, Mg2+ and Ca2+?

Answer 39

Hypokalaemia Hyponatraemia Hypomagensaemia Hypercalcaemia

Question 40

Effect of thiazide diuretics on glucose and lipid levels

Answer 40

Hyperglycaemia | Hyperlipidaemia

Question 41

Can thiazide diuretics lead to gout?

Answer 41

Yes

Question 42

Effect of thiazide diuretics on blood counts?

Answer 42

Can cause low blood counts

Question 43

What rarer side effect can thiazide diuretics have in men?

Answer 43

Impotence

Question 44

Would an equipotent of thiazide or loop diuretic tend to cause a greater degree of hypokalaemia?

Answer 44

Thiazide (Loop diuretics have a shorter duration of action = intermittent compensation)