Ch.20: Diuretics (Swift) Flashcards
Almost all diuretics exert their effect where? What drug is the exception to this?
from the luminal side. Spironolactone.
diuretics to know
mannitol furosemide spironolactone chlorothiazide triamterene
Which diuretic is freely filtered by the glomerulus into the urine? How are other diuretics filtered?
mannitol. Most others are highly protein bound and require active transport/secretion by the proximal tubule into the urine
how does mannitol work?
freely filtered into tubular lumen. Increases tubular fluid osmolality, impairing passive water reabsorption (water wants to stay in the lumen)
mannitol contraindication**
CHF. It gets retained in ECF, which increases venous congestion
Can you use loop diuretics in CHF patients?**
yes. They are the diuretic of choice for this!
how do loop diuretics work?**
- block Na/K/Cl co-transporter in ascending limb of loop of Henle
- cause increased water, Na/K/Cl/Ca/Mg excretion
- decrease max. urinary concentrating and diluting ability
side effects of diuretics
- use up water and Na
- dehydration
- K loss –> ventral flexion of neck
why are loop diuretics diuretic of choice for CHF?
cause greater urine volume and less Na loss than other diuretics
which diuretics of ones you have to know are loop diuretics?
furosemide (lasix)
Furosemide must always be used in combo with ___***
ACE inhibitor to block harmful effects
how do thiazide diuretics work?**
inhibit Na/Cl transport in the distal convoluted tubule (less powerful than loop diuretics)
name a thiazide diuretic
chlorothiazide
how do K sparing diuretics work?
competitive antagonists for aldosterone. Block aldosterone-stimulated Na reabsorption and K and H excretion in the lat distal tubule. Have WEAK diuretic effect and are usually used in combo
name a K sparin diuretic
spironolactone
