Diuretics

Question 0

Carbonic anhydrase inhibitors ADRs

Answer 0

Metabolic acidosis

Hypokalaemia

Question 1

Carbonic anhydrase inhibitors

Answer 1

Act on PCT
Prevent NaCl and HCO3 reabsorption
Na, K and PO3 are excreted

Question 2

Acetazolamide

Answer 2

Carbonic anhydrase inhibitor

Used for glaucoma

Question 3

Loop diuretics mechanism

Answer 3

Act on the thick ascending limb of the loop of Henle
Block the NaKCC symporter
This also inhibits Mg and Ca reabsorption as they are coupled

Question 4

Loop diuretic ADRs

Answer 4

Hypokalaemia
Frusemide nephrotoxic, ototoxic
Bumetinide myalgia

Question 5

Frusemide pharmacokinetics

Answer 5

50% oral uptake
T1/2 ~90 mins
Starts to work after about 30 mins (IV)

Question 6

Bumetinide pharmacokinetics

Answer 6

90% oral uptake (reduced in severe gut oedema, give IV)

Question 7

Bumetinide

Answer 7

Loop diuretic

Question 8

Frusemide

Answer 8

Loop diuretic

Question 9

Loop diuretics uses

Answer 9

Heart failure

Pulmonary oedema

Question 10

Thiazides mechanism

Answer 10

Distal tubule
NaCl symporter
Promote Ca reabsorption

Question 11

Thiazides uses

Answer 11

Hypertension

Can combine with loop diuretics

Question 12

Thiazides ADRs

Answer 12

Hypokalaemia
Erectile dysfunction
Hypercalcaemia
Gout

Question 13

Bendroflumethiazide

Answer 13

Thiazide

Question 14

Benzothiadiazine

Answer 14

Thiazide structural basis

Question 15

Thiazide DDIs

Answer 15

Steroids - hypokalaemia
Digoxin - hypokalaemia, increased digoxin binding (toxicity)
Carbamazepine - hyponatraemia
Beta blockers - hyperglycaemia, hyperlipidaemia, hyperuricaemia

Question 16

Thiazide contraindications

Answer 16

Gout

Question 17

Aldosterone antagonist mechanism

Answer 17

Collecting duct
Prevent Na reabsorption (les NaKATPase)
Blunt K and H secretion

Question 18

Spironolactone mechanism

Answer 18

Aldosterone antagonist

Question 19

Spironolactone ADRs

Answer 19

Hyperkalaemia

Painful gynaecomastia

Question 20

Uses of aldosterone antagonists

Answer 20

Hypertension in Conn’s
With loop in HF
Ascites in cirrhosis

Question 21

Aldosterone antagonist DDIs

Answer 21

Hyperkalaemia with ACE inhibitors

Question 22

Aldosterone antagonist ADRs

Answer 22

Androgen cross reactivity (gynaecomastia)

Hyperkalaemia

Question 23

Demeclocycline

Answer 23

ADH antagonist

Used in SIADH

Question 24

Lithium

Answer 24

ADH antagonist

Question 25

Digoxin

Answer 25

Inhibits tubular NaKATPase Diuretic Used in AF and flutter as an antiarrhythmic

Question 26

Amiloride mechanism

Answer 26

Blocks Na channels in DT and CD (NHE+ENaC) K sparing Can be given with thiazides

Question 27

Mannitol

Answer 27

Osmotic diuretic Increased osmolarity, drawing fluid into lumen Used in cerebral oedema

Question 28

Diuretic general ADRs

Answer 28

``` Metabolic abnormalities Electrolyte disturbance Hypovolaemia Hypotension Acute renal failure Anaphylaxis Rash ```

Question 29

Causes of diuretic resistance

Answer 29

``` Non compliance High Na intake Incomplete treatment of underlying disorder Poor absorption Volume depletion NSAIDs ```

Question 30

Osmotic diuretic ADRs

Answer 30

Excessive fluid loss | Electrolyte imbalance

Question 31

Loop diuretics DDIs

Answer 31

Not with Aminoglycosides (nephrotoxicity) | Not usually with digoxin or steroids (hypokalaemia)