PHARMACOLOGY Flashcards
which type of diuretic enters the kidney tubules by OATs (organic anion transporters) (2)
thiazide diuretics
loop diuretics
which type of diuretic enters the kidney tubules by OCTs (organic cation transporters) (1)
K sparing diuretics
think oCt = K
which membrane do all diuretics work on
apical membrane
how do all diuretics decrease body fluid
decrease Na reabsorption = decrease water reabsorption (bc water follows salt)
how does CHF cause oedema
CHF = decreased CO = renal hypoperfusion = activation of RAAS = increase in water and Na = water moves into interstitial fluid = oedema
where do loop diuretics work
what do they block
apical membrane of ascending limb of loop of henle
Na/K/2Cl triple cotransporter
loop diuretic example
furosemide
side effects of loop diuretics (7)
hypokalaemia hyponatraemia hypocalcaemia hypomagnesium hyperuricaemia hypovolaemia metabolic acidosis
apart from Na, K and Cl, what else does a loop diuretic increase the excretion of (2)
Mg and Ca
what might you need to give someone thats on a loop diuretic to prevent them getting muscle weakness etc etc
K supplements
or switch to K sparing diuretic
what else is transported by OATs that wont be able to be transported into tubule if you are using a loop diuretic
what does this cause
urea
hyperuricaemia
thiazide diuretic example
bendroflumethiazide
end in thiazide
where do thiazide diuretics work
what do they block
what does this result in
early distal convoluted tubule
Na/Cl transporter
decreased Na reabsorption = increased K secretion (bc of transporter)
what else is transported by OATs that wont be able to be transported into tubule if you are using a thiazide diuretic
what does this cause
urea
hyperuricaemia
side effects of thiazide diuretics
hypokalaemia hyponatraemia hypomagnesium hyperuricaemia metabolic acidosis hypovolaemia
K sparing diuretic example (4)
amiloride
triamterene
spironolactone
eplerenone
side effects of aldosterone antagonist K sparing diuretics (eg spironolactone, eplerenone) (3)
think about it
gynaecomastia
impotence
menstrual irregularities
how do aldosterone antagonist K sparing diuretics (eg spironolactone) work
block aldosterone binding = inhibit RAAS = no Na reabsorption (normally happens in RAAS to increase BP)
water follows salt
no K secretion (bc no Na reabsorption) = hyperkalaemia
how do K sparing diuretics that aren’t aldosterone antagonists work
enter nephron via OCT (oCt = K)
block Na channel = no K secretion = hyperkalaemia
water follows salt = diuresis
when are K sparing diuretics used
alongside a drug that causes hypokalaemia, one their own will cause hyperkalaemia
example of osmotic diuretic
mannitol IV
how do osmotic diureticsn (mannitol IV) work
filtered at glomerulus but arent reabsorbed/secreted
increase osmolarity of the filtrate = draw water in by osmosis
what is significant about osmotic diuretics (mannitol IV)
not permeable to membrane (so once filtered at glomerulus = stays there)
non renal uses of osmotic diuretics (2)
increased ICP
increased intraocular pressure
