Diuretics

Question 1

Complications of acetazolamide

Answer 1

Metabolic acidosis

Hypokalaemia

Question 2

MoA of acetazolamide

Answer 2

Carbonic anhydrase inhibitor

Question 3

Uses of acetazolamide

Answer 3

Topical for glaucoma

Question 4

Uses of mannitol

Answer 4

Severe cerebral or pulmonary oedema

Question 5

Complications of mannitol use

Answer 5

Excessive H20 loss and hypernatraemia

Question 6

MoA of mannitol

Answer 6

Osmotic diuretic

Question 7

Examples of ADH antagonists and their MoA

Answer 7

Lithium, demeclocycline

Decrease the concentrating ability of the collecting ducts in kidneys to increase H20 excretion in urine

Question 8

Drug interactions with loop diuretics

Answer 8

Digoxin/steroids - hypokalaemia

Aminoglycosides - ototoxic and nephrotoxic

Question 9

Drug interactions with thiazides

Answer 9

Digoxin/steroids - hypokalaemia

Beta blockers - hyperglycaemia/lipidaemia/uricaemia

Question 10

Contraindications for thiazides

Answer 10

Gout

Question 11

Effect of increasing bendroflumethiazide dose on BP

Answer 11

With increasing dose:
First large drop in BP
Decrease in BP becomes smaller and smaller

Question 12

Drug interactions with amiloride and spironolactone

Answer 12

ACEi - hyperkalaemia

Question 13

Side effects of diuretics in general

Answer 13

Electrolyte disturbance
Hypovolaemia
Hypotension
Rash

Question 14

Side effects of thiazides

Answer 14

Gout

Erectile dysfunction

Question 15

Side effects of spironolactone

Answer 15

Gynaecomastia

Question 16

Side effects of bumetanide

Answer 16

Myalgia

Question 17

Reasons for resistance to diuretic therapy

Answer 17

Not treating underlying cause
High salt intake
Non compliance
Poor gut absorption
NSAIDs (vasoconstrict afferent arteriole of glomerulus so decreases GFR)
Volume depletion (decreases filtration of diuretics)
High aldosterone (increases Na reabsorption)

Question 18

3 main indications for diuretics

Answer 18

Heart failure
Hypertension
Decompensated liver disease

Question 19

Why do drugs need altering in renal disease

Answer 19

Can accumulate to toxic levels

Drugs can be nephrotoxic

Question 20

Principles for prescribing in CKD

Answer 20

Avoid nephrotoxins
Decrease dosages in line with GFR
Monitor renal function

Question 21

Principles for prescribing in elderly

Answer 21

Renal function overestimated due to low creatinine (small muscle mass)
Need to start with low dose and titrate up slowly