Diuretics

Question 1

What are diuretics

Answer 1

Diminish Na reabsorption at different sites of nephron

Increase urinary Na and H20 loss

Question 2

Diuretic classes

Answer 2

Carbonic anhydrase inhibitors
Loop
Thiazide
Potassium sparing
Osmotic

Question 3

Acetazolamide

Answer 3

CA inhibitor

Used for- glaucoma, epilepsy, mountain sickness

Question 4

CA inhibitors MOA

Answer 4

Proximal convoluted tubule
Reduces HCO3 absorption
Can cause metabolic acidosis- used as a counter for respiratory/metabolic alkalosis

Question 5

CA inhibitors side effects

Answer 5

Metabolic acidosis
Sedation
Sulphonamide antibiotics - bone marrow suppression

Question 6

Loop diuretic examples

Answer 6

Frusemide

Bumetanide

Question 7

Loop diuretics MOA

Answer 7

Thick ascending limb
Stop Na+/K+/2Cl- co-transporter
K+ normally secreted to allow electrochemical gradient for Mg and Ca to be absorbed- doesn’t happen anymore so decreased Mg2+ and Ca2+ absorption

Question 8

Loop diuretics clinical use

Answer 8

Most potent diuretic

Excretion of potassium, sodium, water, calcium and magnesium

Question 9

Loop diuretics indications

Answer 9

Hypertension
Heart failure
Volume overload from CKD

Question 10

Loop diuretic side effects

Answer 10

Hypokalaemia
Dehydration –> acute renal failure
Kidney stones
Deafness

Question 11

Thiazide diuretics examples

Answer 11

Bendroflumethiazide

Hydrochlorothiazide

Question 12

Thiazide like drugs

Answer 12

Chlorthalidone
Indapamide
Metolazone

Question 13

Thiazide MOA

Answer 13

Distal convoluted tubule
Blocks Na+/Cl- ATPase
–> stops Na+ being absorbed

Question 14

Thiazide diuretics clinical use

Answer 14

Antihypertensive
Reduction in plasma volume
Reduction in peripheral resistance

Question 15

Thiazide diuretics side effects

Answer 15

Hypokalaemia
Hypercalcaemia
Hyponatraemia
Hyperglycaemia
Hypercholesterolaemia

Question 16

Potassium sparing diuretics examples

Answer 16

Epithelial Na Channel antagonists

Aldosterone antagonists

Question 17

Epithelial Na channel antagonists

Answer 17

K+ sparing diuretics
Amiloride
Triamterene

Question 18

Aldosterone antagonists

Answer 18

K+ sparing diuretics
Spironolactone
Eplerenone

Question 19

Amiloride MOA

Answer 19

Collecting tubule
Blocks Na+ channel
Doesn’t affect K+

Question 20

Amiloride Clinical uses

Answer 20

Heart failure
Hypokalaemia (from other diuretics)
--> co-amilofruse
--> co-amilozide
Cirrhosis

Question 21

Amiloride Side effects

Answer 21

Hyperkalaemia

Hyponatraemia

Question 22

Spironolactone MOA

Answer 22

Collecting tubule

Aldosterone antagonist- normally aldosterone upregulates ENaCs

Question 23

Aldosterone inhibitors clinical uses

Answer 23

Hyperaldosteronism (Conns)
Heart failure
Hypokalaemia (from other diuretics)
Cirrhosis

Question 24

Aldosterone inhibitors side effects

Answer 24

Hyperkalaemia
Gynecomastia
Hyponatraemia

Question 25

Osmotic diuretics example

Answer 25

Mannitol

Question 26

Osmotic diuretic MOA

Answer 26

Osmotically active molecule in tubular lumen- stops water reabsorption
Reduces reabsorption of all solutes- Na, K, urea
Molecule drags Na from interstitial space

Question 27

Osmotic diuretics clinical indications

Answer 27

Cerebral oedema

Oliguric acute renal failure

Question 28

Osmotic diuretic side effects

Answer 28

Transient fluid overload (pulmonary oedema)

Question 29

Other non pharmacological osmotic diuretics

Answer 29

Glucose- gives DKA

Urea- fives disequilibrium syndrome

Question 30

When not to give diuretics

Answer 30

Hypotensive
Dehydrated
Hypokalaemic (loop, thiazide)
Hyperkalaemic (amiloride, aldosterone antagonists)
Post surgery with poor urine output