16 terms

Diuretic Agents

Exam 3
main purpose of diuretics
increase urine output
eliminate excess fluid from the body
lowers blood pressure
at level of umbilicus
22% of cardiac output
active organ
decreased blood flow to it can cause renal damage or failure
functional unit of the kidney
glomerular filtration
20% of total blood flow thru nephron
99% reabsorbed in tubules
1% excreted as urine
adult output = 30 to 60 ml/hour
is a mineralocorticoide secreted by the adrenal cortex
increases NA & H2O reabsorption in distal tubule
acid base balance
Na reabsorption
with Cl to preserve neutrality
exchange of Na for H or K
5 major diuretic groups
carbonic anhydrase
osmotic diuretics
loop diuretics
thiazide diuretics
potassium sparing
carbonic anhydrase inhibitors
increase diuresis of sodium bicarbonate
poor diuretic b/c ends up being reabsorbed in the loop of Henle
inhibitors block Na & HCO3 in PCT
Loop diuretics KNOW
inhibit the reabsorption of Na, Cl
the most potent diuretics
use for pulmonary edema, renal failure, CHF, heart failure, edema
act principally at the thick ascending limb of the loop of Henle
most common diuretics used KNOW
Forosemide (Lasix)
Bunetanide (Bumex)
thiazide diuretics
block Na & Cl reabsorption in the distal tubule
less potent than loop
indications: mild edema, HTN
osmotic diuretics
block reabsorption of NaCl in the proximal tubule & descending limb of the loop of Henle
up to 20% of filtered load NaCl & water to be excreted in the urine
Mannitol KNOW
selected agent
lower toxicity
short half life
rapid onset
maintained continued diuretic action
continuous infusion
used with head injury
potassium sparing
block reabsorption of Na in the distal tubule
in the distal tubule:
Na is exchanged for potassium & hydrogen
blocking this exchange makes these agents potassium sparing diuretics
diuretic complications
volume depletion & electrolyte imbalance - most common
hypokalemia thru volume loss & electrolyte shifts-loops especially
acid base imbalance
tinnitus & hearing loss
classification of Lasix & Bumex
loop diuretics