6 - Diuretics

Question 1

the REEM mnemomic is great for functions of the kidney - outline it now

Answer 1

Regulatory
– Fluid balance
– Acid-base balance
– Electrolyte Balance

Excretory
– Waste products (protein metabolism)
– Drug elimination
– Glomerular Filtration
– Tubular Secretion

Endocrine
– Renin
– Erythropoetin
– Prostaglandins
– 1-alpha calcidol

Metabolism
– Vitamin D
– Polypeptides
Insulin
– Drugs
Morphine
paracetamol

Question 2

name the 8 types of drugs acting on the renal tubules

Answer 2

Carbonic anhydrase inhibitors
• Osmotic Diuretics
• SGLT2 inhibitors
• Loop Diuretics - Furosemide - KEY
• Thiazides
• Potassium sparing diuretics
• Aldosterone antagonists
• ADH Antagonists

a diureatic increase urine production
a natiureatic causes loss of sodium in urine
a aquaretic causes loss of water without electrolytes

do the lec 6 slide 13 cover test for where these drugs specifically act (probs not too key)

Question 3

explain the mechanism if carbonic anhydrase inhibtors

osmotic agents eg mannitol

SGLT2 Inhibitors

Loop diuretics

thiazide diuretics

Answer 3

after explaining the broad mechanism of each one, check vs slides

Question 4

name the key ADH antangonists drug

when may you want to use it

Answer 4

ADH antagonists – ‘Aquaretics’
• Tolvaptan
• ADH antagonist.
• Diuretic but not natriuretic.
• Used to treat hyponatraemia (&
prevent cyst enlargement in
APCKD)

will lead to dilute urine and hence raised the serum sodium level

Question 5

what two common drugs have diuretic action ?

How

Answer 5

alcohol - inhibits ADH release

caffine - increase GFR and Decrease thubular Na reabsorption

Question 6

outline the generic adverse drug reactions of diuretics

Answer 6

• Hypovolaemia & hypotension
– Activates RAAS
– Can lead to acute kidney injury

• Electrolyte Disturbance (Na+, K+, Mg2+, Ca2+) commonly will cause hypokalemia and then a metabolic acidosis
• Metabolic Abnormalities (depends on individual drug)
• Anaphylaxis / photosensivity rash etc (rare)

Question 7

specific ADR’s of thiazides are ?

Answer 7

• Gout
• Hyperglycaemia
• Erectile dysfunction
• ↑LDL ↑TG
• Hypercalcaemia

Question 8

specific ADR’s of frusemide are ?

Answer 8

• Ototoxicity
• Alkalosis
• ↑LDL ↑TG
• Gout

Question 9

Specific ADR’s of spironolactone are ?

Answer 9

Hyperkalaemia
• Impotence
• Painful gynaecomastia

Question 10

specific ADR’s of bumetanide are ?

Answer 10

Myalgia

Question 11

DDIs of diuretics

there is a key table on slide 26

do a cover test of it

Answer 11

do it - key

Question 12

outline some cases where you may use diuretics

and what diuretics you may use

Answer 12

hypertension - thiazide diuretics, spironolacotone

heart failure - loop diuretics, spironolactone

decompensated liver disease - spirono and loop diuretics

nephrotic syndrome - loop diuretics, thiazides, K+ spare diuretic

Question 13

Breif patho phys and treatment of CKD

Answer 13

↓GFR leads to salt and water retention
• Loop diuretics
• Alkalosis & kalliuretic effects potentially beneficial
• Generally avoid K+-sparing diuretics

Question 14

if gut odema give fruesamide via IV to ensure it reaches kidneys

Answer 14

bonus - loop diuretics treat odema w/wo hypertenison in advances CKD

can cause alkalosis and metabloic effects

Question 15

diuretics will not work effecitvley if taken with salt

Answer 15

key bonus