what drug class helps in treating hypertension and mobilizes edematous fluid associated with heart failure, cirrhosis or kidney disease?
Diuretics
3 basic renal processes
Filtration
reabsorption
secretion
Out of reabsorption and secretion, which renal process is more important
reabsorption
diuretics work primarily by interfering with what renal process
reabsorption
what part of the loop of Henle is freely permeable to water
Descending limb
what basic mechanism of action do most diuretics share
blockade of sodium and chloride reabsorption
drugs that act early in the nephron have the opportunity to
block the greatest amount of solute reabsorption which produces the greatest diuresis
what are the 3 most common adverse effects for diuretics
acid base imbalance
hypovolemia
altered electrolyte levels
adverse effects of diuretics can be minimized by
using a short acting diuretic
timing drug administration such that the kidney is allowed to operate in a drug free manner in between periods of diuresis
what type of diuretics is the most effective
loop diuretics
site of action for loop diuretics
loop of henle (blocks reabsorption of sodium and chloride
Furosemide (Lasix) is what type of diuretic
Loop diuretic
Furosemide (Lasix) - diuresis begins in ___ min and persists for ___ hours
60 min
8 hours
what conditions can you use lasix for
pulmonary edema associated with CHF
Edema of hepatic, cardiac ,or renal origin that has been unresponsive to less efficacious diuretics
HTN not controlled with other diuretics
What diuretic can be used in patients with severe renal impairment and can be used when renal blood flow and GFR is low
Furosemide (Lasix)
if treatment with furosemide alone is insufficient what can be added
thiazide diuretic
what electrolytes problems associated with Furosemide
Hyponatremia
hypochloremia
dehydration
How do you decrease the risk for dehydration with Lasix
initiate with low doses
adjust doses carefully
monitor weight loss every day
signs of hypotension associated with Lasix
dizziness
lightheadedness
fainting
why can lasix cause hypotension
loss of volume
relaxation of venous smooth muscle which reduces venous return to the heart
what should you monitor with lasix r/t hypotension
Blood pressure
If BP falls precipitously (very steeply), d/c med
how do you minimize postural hypotension
rising slowly
loop diuretics and hearing
loop diuretics can cause hearing impairment
what loop diuretic can cause irreversible hearing loss
ethacrynic acid (Edecrin)
What diuretic can cause transient deafness
Lasix
are diuretics safe in pediatric population
yes, in smaller doses
Pregnant women and diuretics
can cause maternal death, abortion and fetal resorption, risks and benefits must be considered
Breastfeeding and diuretics
may decrease milk production, not enough data to know if it transfers to milk
older adults and diuretics
diuretics are the most common cause of adverse med reactions and interactions in older adults. monitor closely for dehydration and cardiac dysrhythmias
what type of diuretic is safer with digoxin
potassium sparing diuretics. Low potassium with digoxin increases risk for serious digoxin induced tox (ventricular dysrhythmias)
what antibiotic should be avoided with lasix due to increasing the risk for hearing loss
aminoglycoside diuretics (Gentamycin)
what drug class are these drugs
Ethacrynic acid (Edecrin)
torsemide (Demadex)
bumetanide
loop diuretics
what 2 loop diuretics are approved for hypertension
Lasix
Torsemide (Demadex)
Between Loop diuretics and Thiazides, which produces max diuresis
Loop diuretics
what diuretic blocks the reabsorption of sodium and chloride in the early segment of the distal convoluted tubule
thiazide diuretics
Thiazides are ineffective when the ___ is Low
GFR (less than 15-20 mL/min)
can thiazides be used in patients with renal impairment
no
when does diuresis begin for Thiazides
within 2 hrs
peaks 4-6 hours
persists up to 12 hours
the primary indication for hydrochlorothiazide is
hypertension
what type of diuretic is preferred for mobilizing edema associated with mild to moderate heart failure
Thiazides
what is the difference in adverse effects for loop and thiazide diuretics
thiazide diuretics are not ototoxic, all others are the same
how are potassium sparing diuretics used
typically in combination with loop and thiazide diuretics bc their diuretic effects are limited but helps to prevent loss of potassium
What category are these meds?
spironolactone
triamterene
amiloride
potassium sparing diuretics
which diuretic blocks the actions of aldosterone in teh distal nephron.
Potassium sparing diuretics
inhibition of aldosterone does what to potassium and sodium
retains potassium
increases excretion of sodium
the effects of spironolactone takes up to ___ to develop
48 hours
black box warning for spironolactone
tumorigenic in rats. avoid unnecessary use
spironolactone is used primarily for
htn and edema
electrolyte adverse effect for potassium sparing diuretic
hyperkalemia
endocrine effects of spironolactone
it is a steroid derivative can cause gynecomastia menstrual irregularities impotence hirsutism deepening of the voice
drug interactions for potassium sparing diuretics
risk for hyperkalemia with potassium supplements, salt substitutes (which contain potassium chloride) or other potassium sparing diuretics
also ACE inhibitors, ARBS and Direct renin inhibitors
How is Triamterene different from other potassium sparing diuretics such as spironolactone
acts on the sodium potassium pump itself without affecting aldosterone
acts within hours as opposed to days
still minimal diuresis
adverse effects of Triamterene
nausea vomiting leg cramps dizziness Blood dyscrasias occur rarely
Where does Amiloride act
similar to Triamterene
what lab needs to be monitored with Spironolactone, Triamterene and amiloride
Potassium on a regular basis
diet instructions for a potassium sparing diuretic
restrict intake of potassium rich foods
examples of potassium rich foods to avoid in Potassium sparing diuretics
sports drinks papaya cantaloupe prune juice honeydew melons bananas raisins mangoes kiwis orange juice tomatoes oranges tomato juice white potatoes sweet potatoes asparagus pumpkin brussels sprouts salt substitutes that use potassium chloride instead of sodium chloride low sodium milk products
what diuretics waste potassium, commonly need a potassium supplement when taking
loop diuretics
do you need a potassium supplement in Thiazides
no
spironolactone with sodium and potassium
increases NA and decreases K