Diuretics

Question 1

Thiazide diuretics MOA

Answer 1

Inhibits sodium re absorption and so water, at the beginning of the distal convoluted tube

Question 2

How do diuretics affect urine output

Answer 2

Increases urine output

Question 3

What are examples of thiazides
Thiazide like

Answer 3

Bendroflumethiazide

Chlortalidone
Indapamide

Question 4

Whats the onset and duration of action of thiazides of oral administration

Answer 4

Onset is 1-2 hours
Duration is 12-24hrs

Question 5

What time of day do you give diuretics and why

Answer 5

Morning, to avoid diuresis at night interfering with sleep

Question 6

Whats the potency of bendroflumethiazide, indapamide and chlortalidone

Answer 6

Moderate potency

Question 7

When are lower doses of thiazides used and when are higher doses used

Answer 7

Lower doses are used in hypertension and higher doses are used in oedema due to congestive HF

Question 8

Do higher or lower doses of thiazides have more affect on biochemical balance (electrolytes)

Answer 8

Higher doses

Question 9

When is bendroflumethiazide used? Conditions

Answer 9

Mild or moderate HF or hypertension , oedema

Question 10

Which thiazide can be given on alternate days and why?

Whats it’s indication?

Answer 10

Oedema and hypertension and HF
Chlortiladone
Because its long acting

Question 11

Indication for indapamide

Answer 11

Hypertension
It is now first line
Bendroflumethiazide can be used first line if already stable on it

Question 12

Why is indapamide preferred in comparison to bendro in hypertension

Answer 12

Less aggravation of diabetes and lowers BP without having a great affect on electrolytes

Question 13

What are thiazides contraindicated in.

Hint: electrolytes

Answer 13

Hypokalaemia, addisons disease,
Hyponatraemia, hypercalcaemia, hyperuricaemia

Question 14

Which diuretic has greater risk of hypokalaemia?

Answer 14

Thiazides

Question 15

Which drug interacts with thiazides and what can you give instead?

Answer 15

Thiazides interact with cardiac glycosides such as digoxin due to hypokalaemia risk

Give potassium sparing diuretic or potassium supplements

Question 16

Hypokalaemia is dangerous in ….

Answer 16

Severe cardiovascular disease

Question 17

In liver disease hypokalaemia can lead to ….. especially in ……. Hence avoid using …… in liver disease

Answer 17

Encephalopathy

Alcoholic cirrhosis

Thiazides

Question 18

What thiazide doses would you initially give to elderly and why

Answer 18

Low doses

More prone to SE

Question 19

What are the SE of thiazides

Answer 19

Skin reactions, constipation, electrolyte imbalance, PH

Question 20

Dont use thiazides in long term treatment of ….. instead recommend …..

Answer 20

Gravitational oedema

Raise legs, increased movement, stockings

Question 21

What do thiazides exacerbate. Why?

Answer 21

Diabetes
Gout

Due to hyperuricaemia and hyperglycaemia

Question 22

In gestational hypertension can we give thiazides? Why?

Answer 22

No
Can cause malformations, neonatal thrombocytopenia, electrolyte imbalance, bone marrow suppression and jaundice

Question 23

Can we use thiazide diuretics in severe liver disease? Why?

Answer 23

No
Causes hypokalaemia which in liver disease causes encephalopathy

Question 24

Dont use thiazides if eGFR ….. because…..

Answer 24

<30ml/min/1.73
Ineffective

Question 25

What are examples of loop diuretics?

Answer 25

Furosemide Bumetanide

Question 26

Loops MOA

Answer 26

Inhibits reabsorption of Na and water from the ascending loop of henle

Question 27

Indications of loops (furosemide, bumetanide)

Answer 27

Pulmonary Oedema in HF, and in Resistant hypertension

Question 28

Which diuretics are stronger and which can be used for resistant oedema?

Answer 28

Loop diuretics are stronger and can be used for resistant oedema

Question 29

Hyperglycaemia is more likely in loops or thiazide diuretics?

Answer 29

Thiazides

Question 30

Which diuretic is more powerful? Loop or thiazide

Answer 30

Loop

Question 31

Loop diuretics can exacerbate…..

Answer 31

Diabetes and gout Diabetes more exacerbated in thiazide use

Question 32

Onset of furosemide and bumetanide and duration

Answer 32

1 hour Diuresis is complete within 6 hours hence can be given BD without interfering with sleep

Question 33

CI of loop (furosemide and bumetanide)

Answer 33

Renal failure (eGFR <30), severe hypokalaemia, hyponatraemia, liver cirrhosis

Question 34

In ….. impairment, loops can cause ……. At higher doses or IV administration

Answer 34

Renal impairment Ototoxic - deafness and tinnitus

Question 35

Why are loops CI in renal impairment

Answer 35

Higher doses cause deafness/ ototoxic

Question 36

What colours the urine blue

Answer 36

Triamterene and furosemide

Question 37

Which diuretics are classed as ‘weak’ and which are classed as powerful

Answer 37

Amiloride and triamterene - weak Bumetanide, furosemide are powerful

Question 38

Can you give spironolactone and potassium supplements

Answer 38

No because of hyperkalaemia risk

Question 39

Which drug is CI with potassium sparing diuretics

Answer 39

ACEi/ARBs

Question 40

Which potassium sparing diuretics are strong

Answer 40

Spironolactone and epleronone

Question 41

What is a SE of spironolactone

Answer 41

Gynaecomastasia (breast tenderness)

Question 42

When is combination diuretic therapy used?

Answer 42

When oedema is resistant to one diuretic

Question 43

Whats an example of an osmotic diuretic and whats its indications?

Answer 43

Mannitol Cerebral oedema and raised ocular pressure

Question 44

Give an example of a carbonic anhydrase inhibitor Whats its indication

Answer 44

Acetazolamide - weak diuretic Glaucoma, epilepsy

Question 45

Dont give acetazolamide if pt is allergic to….

Answer 45

Sulfonamide

Question 46

Can you give acetazolamide in renal and hepatic impairment? Explain

Answer 46

No Hepatic - hypokalaemia causes encephalopathy Renal- risk of metabolic acidosis

Question 47

Whats the drug class of brinzolamide and dorzolamide? Indications?

Answer 47

Used in open angle glaucoma and raised intraocular pressure when BB ineffective or CI and inhibits formation of aq humour

Question 48

Can you give NSAIDS with diuretics

Answer 48

No Increased Risk of acute renal failure

Question 49

Which is more potent furosemide ir bumetanide

Answer 49

Bumetanide