Medicine Block 8

Front 1

what three things do diuretics increase

Back 1

urine flow rate
urinary sodium excretion
urinary water excretion

Front 2

what percentage approximately of filtered Na and water is excreted

Back 2

Na 0.5%
water 1%

Front 3

what is the main mechanism of diuresis by diuretics

Back 3

decreasing reabsorption of Na

Front 4

what is another mechanism of diuresis (but not main)

Back 4

increase in GFR

Front 5

what are non reabsorbable solute "osmotic diuretics"?

Back 5

molecules that are given which are not able to be reabsorbed due to big size hence causing diuresis

Front 6

what are two eg of osmotic diuretics

Back 6

Mannitol IV
Glucose excess

Front 7

What is the term for decreased Na reabsorption

Back 7

Natriuresis

Front 8

where are the 5 nephron sites of Na reabsorption

Back 8

1. proximal tubule
2. ascending limb of loop of henle
3. distal tubule
4. early collecting tubule
5. late collecting tubule

Front 9

how does blocking the Na movement at the ascending limb of the loop of henle affect the urine?

Back 9

The urine is unable to be DILUTED or CONCENTRATED with sodium

Front 10

how does blocking the Na movement at the distal tubule affect urine?

Back 10

you can't DILUTE the urine

Front 11

what two ions are affected by diuretics (other than Na and H2O)

Back 11

potassium (hypokalaemia)
H+ ions (alkalosis)

Front 12

what are the three receptors for Na in the proximal tubule

Back 12

1. facilitated transport of Na + glucose/phosphate etc
2. antiport of Na and H+
3. Na+/K+ATPase

Front 13

what happens to H+ that is secreted into the brush border the ureter

Back 13

combines with HCO3 -> H2CO3
broken down by carbonic anhydrase to
H2O and CO2

Front 14

what happens to the H2O and CO2 that is produced by the H+ ions at the brush border of the ureter

Back 14

it is reabsorbed back into the proximal tubule to combine to H2CO3> HCO3+ + H+
then HCO3+ is reabsorbed back into the blood (balances pH and prevents acidosis)

Front 15

what is the mechanism of azetozolamide

Back 15

carbonic anhydrase inhibitor
this inhibits the breakdown of H2CO3 in the brush border hence slows the antiport receptor and reabsorption of HCO3+ back into blood
result: diuresis

Front 16

what is the side effect of azetolamide

Back 16

metabolic acidosis
less HCO3+ reabsorbed into the blood

Front 17

http://www.youtube.com/watch?v=6Wc4f2KnbYo
diuretic actions

Back 17

..

Front 18

what are the two receptors for sodium in the ascending limb of the loop of henle?

Back 18

1. 3Na/2K ATPase
2. Na/K/Cl Co transporter

Front 19

How does lasix work? (furesemide)

Back 19

blocks the Na/K/Cl Co transporter
decreases the Na reabsorption
hence inc Na excretion
Natriuresis and diuresis

Front 20

what other ions are lost in excretion with lasix?

Back 20

Calcium and magnesium

Front 21

where does the hypokalaemia occur with loop diuretics?

Back 21

COLLECTING TUBULES

Not at the ascending limb
you send more Na down to the collecting tubule with loop diuretics
This will cause more Na reabsorption at the collecting tubules
hence more K secretion (hypokalaemia) at the collecting tubules

Front 22

what side effect regarding ions is associate with thiazides

Back 22

hypercalcaemia

Front 23

which diuretic is erecticle dysfunction associated with

Back 23

thiazides

Front 24

above what CrCL does thiazides work

Back 24

above 30 mL/min
because the thiazides have to be filtered to work

Front 25

which type of diuretics have a vasodilatory effect

Back 25

thiazides

Front 26

what does lasix in high doses cause for elderly

Back 26

deafness
more likely to occur in ppl taking other contributing drugs like gentamicin

Front 27

what are the four sfx of diuretics starting with 'hypo'

Back 27

hypovolaemia
hyponatraemia
hypokalaemia
hypomagnesemia

Front 28

where does metabolic acidosis occur in the nephron

Back 28

proximal tubule

Front 29

where does hyperkalaemia occur in the nephron

Back 29

collecting tubule

Front 30

what are three metabolic sfx to diuretics

Back 30

glucose intolerance (changes insulin receptors and also from hypokalaemia
hyperlipidaemia
hyperuricaemia

Front 31

what is the mechanism of hyperlipidaemia in diuretics?

Back 31

unclear
but it may be activation of SNS, RAAS, insulin sensitivity

Front 32

what is the mechanism of the sfx hyperuricaemia

Back 32

directly and indirectly increases uric acid reabsorption in the proximal tubule

Front 33

what is one diuretic that is not associated with hyperlipidaemia

Back 33

indapamide

Front 34

what is a natural diuretic

Back 34

parsley

Front 35

what natural food causes hypertension and hyperkalaemia

Back 35

liquorice