Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

1. Renal > Pharmacology 1 > Flashcards

Pharmacology 1 Flashcards

1
Q

What is oedema due to?

A

increase in hydrostatic capillary pressure or a decrease in osmotic capillary pressure of plasma resulting in an increase of interstitial fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does an increase in interstitial fluid result in?

A

decrease in BP and hypovolaemia - which activates RAAS which leads to sodium and water retention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What drugs act in the proximal convoluted tubule?

A

carbonic anhydrase inhibitors - block Na/H exchange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What drugs act in the early distal convoluted tubule?

A

carbonic anhydrase inhibitors

thiazide diuretics - block Na/Cl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What drugs act in the thick ascending limb of loop of henle?

A

loop diuretics - Na/K/2Cl transporter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What drugs act in the collecting tubule and duct?

A

potassium sparing diuretics - block Na/K exchange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the action of carbonic anhydrase inhibitors?

A

depress HCO3 reabsorption by inhibiting catalysis of Co2 hydration and dehydration which increases HCO3, Na and H secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How long do carbonic anhydrases act for?

A

self limiting so only a short period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where do most diuretics act?

A

apical membrane - so must enter the filtrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the two mechanisms that diuretics can enter the filtrate?

A

glomerular filtration - if not bound to plasma protein

secretion via organic anion transports (OATs) or organic cation transports (OCTs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the characteristics of OATs?

A

for acidic drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the action of OATs at the basolateral membrane?

A

organic anions enter the cell against a concentration gradient in exchange for a-ketoglutarate via OAT4
a-KG enters the cell against a concentration gradient via NaDC3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the action of OATs at the apical membrane?

A

OAs are actively pumped out of the cell to the lumen via multidrag resistance protein 2 and 4 (MRP2/4) and BCRP through primary active transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the characteristics of OCTs?

A

for basic drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the action of OCTs at the basolateral membrane?

A

organic cations enter the cell mainly by OCT2 - driven by the negative potential of cell interior and against a concentration gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the action of OCTs at the apical membrane?

A

OCs enter the lumen via MATES in a rate limiting manner and by MDR1 in an active transport manner

17
Q

Give two examples of loop diuretics?

A

furosemide and bumetanide

18
Q

What is the action of loop diuretics?

A

binds to the Cl site of the Na/K/2Cl transporter in the ascending limb of henle
causes impaired Ca/Mg reabsorption as K movement creates a positive charge which drives Ca/Mg reabsorption
there is also an increased Na load delivered to distal regions of the nephrons which causes K loss

19
Q

What are the general features of loop diuretics?

A

cause 15-25% of filtered Na to be excreted
also possess a venodilator affect due to the increased formation of vasodilation prostaglandins and opening of K channels in resistance vessels
absorbed from the GI tract
strongly bind to plasma proteins

20
Q

By what mechanism do loop diuretics enter the nephron?

A

OAT

21
Q

What are the side effects of loop diuretics?

A 
hyonatremia
hypotension
can precipitate gout attack - hyperuricaemia 
metabolic alkalosis
hypomagnesium
hypovolaemia
hypokalaemia
deafnesss
22
Q

When are loop diuretics contraindicated?

A

hypovolaemia

dehydration

23
Q

What is Bartter Syndrome?

A

autosomal recessive

salt and water wasting

24
Q

Name a thiazide diuretic?

A

bendroflumethiazide

25
Q

Where do thiazide diuretics act?

A

distal convuluted tubule

26
Q

What is the action of thiazide diuretics?

A

Inhibit NaCl reabsorption by binding to the Cl site on the Na/Cl symptorter - causing the excreteion of Cl and Na, and therefore H20
It also increases Na load delivered to collecting tubule which stimulates Na exchange with K and H, increasing K and H secretion

27
Q

How do thiazide diuretics enter the nephron?

A

OAT

28
Q

What are the characteristics of thiazide diuretics?

A

well absorbed from GI tract
cause 5% of Na to be excreted
has a vasodilator action

29
Q

What are thiazide diuretics contraindicated in?

A

hypokalaemia

hyponatraemia and gout - less so

30
Q

What are the side effects of thiazide diuretics?

A 
hypokalaemia
metabolic alkalosis
hypovoleamia
hypotension
hypomagnesium
hyperuricaemia - can precipitate gout
impaired glucose tolerance in diabetics
erectile dysfunction
31
Q

What is the role of aldosterone?

A

aldosterone acts via cytoplasmic receptors to:

  1. increase synthesis of a protien that activates ENaC channels
  2. increases ENaC expression
  3. increases abundance of Na/K/ATPase
  4. rapidly increase expression of ENaC via SgK1
32
Q

What secretes K into the collecting tubule?

A

ROMK and BK

33
Q

How does Na reabsorption result in K secretion?

A

Na reabsorption results in charge separation that makes the lumen more negative and depolarises the lumen vs basolateral membrane
increased driving force of K across the lumenal membrane leads to enhanced secretion of K, SgK1 increases K channel (ROMK) number in apical membrane
K is washed away by urinary flow rate that indirectly activates ROMK channels

34
Q

Name four potassium sparing diuretics?

A

amiloride
triamterene
spironolactone
eplernane

35
Q

What is the action of amiloride and triamterene?

A

block the apical Na channels in the collecting tubules, decreasing Na permeability
enter the nephron via OCTs in the proximal tubule
Increases Na, Cl and H20 excretion
decreases K excretion
triamterene is well absorbed from GI tract
Amiloride is poorly absorbed

36
Q

What is the action of spironolactone and eplernane?

A

antagonise aldosterone at cytoplasmic aldosterone receptors - compete with it
gain access to the cytoplasm via the basolateral membrane
increase Na excretion
decrease K excretion
well absorbed from GI tract

37
Q

What are the side effects of potassium sparing diuretics?

A

if given alone can cause hyperkalaemia

38
Q

When are potassium sparing diuretics contraindicated?

A

severe renal impairment
hyperkalaemia
addisons - aldosterone is already low

1. Renal (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions