diuretics Flashcards
Specific Goals of Heart Failure Managementwith Pharmacotherapy
- reduction of congestion
- modulate neurohormonal activation
- improve flow
reduction of congestion can be accomplished by
fluid otpimization with diuretics is a mjor part of HF therapy
modulate neurohormonal activation, resulting in long term stabilization, positive remodeling and increased survival with
RASS antagonists and
B blockers
improve blood flow with
vasodilators
This can be difficult and can require mechanical devices or transplantation
diuretics are used first as need to
reduce cogestion
how do diuretics reverse congestion?
- Reverse Na+ and fluid retention
- Relieve volume overload: dyspnea-peripheral edema
- Lowers preload (LVEDP)
Can be used chronically and acutely
Furosemide most common
Torsemide or bumetanide - more reliable absorption
What diuretics are used preferentially and why?
Loop diuretics preferred because of efficacy - can augment with a thiazide diuretic
Are diuretics used chronically or acutely?
both!
most common diuretic used?
- Furosemide most common
2. Torsemide or bumetanide - more reliable absorption
when are ACEIs started?
- during or after optimization of diuretic therapy
2. initiated at low doses and titrated to goal
ACEIs produce
- vasodilation
- decrease aldosterone activation
- antiremodeling effect
ARBs are used in patients
intolerant to ACEIs (most often cough)
benefit from ACEI and ARB together?
No apparent benefit
aldosterone antagonist are added to therapy for
- LVEF < 30-35%
2. optimized on ACEI/ARB and β-blocker therapy
Aldosterone antagonists function to
- Blocks aldosterone effect on kidney
- ACEI / ARB aldosterone block is incomplete
- Antiremodeling action plus produces additional Na+ loss at the kidney
aldosterone antagonists you have to carefully monitor
- serum K+ (< 5.0)
- renal function
(GFR > 30 ml/min) as agents are potassium-sparing
what aldosterone antagonist is preferred?
Spironolactone preferred if tolerated - if endocrine side effects (gynecomastia) can use eplerenone
diuretic agents
- Hydrochlorothiazide
- Furosemide (Lasix®)
- HCTZ-Triamterene (Dyazide)
- Spironolactone (Aldactone®)
- Triamterene (Dyrenium®)
- Amiloride (Midamor®)
- Chlorthalidone (Thalitone®)
- HCTZ-Aldactazide (Aldactazide®)
- Bumetanide (Bumex®)
- Torsemide (Demadex®)
- Ethacrynic acid (Edecrin®)
Most diuretics exert effects at
lumenal (urine) surface of renal tubule cells
Diuretics can
Interact with
- membrane transport proteins
- enzyme
- hormone receptor
- osmotic effects preventing water reabsorption
Which Diuretics
Interactions with membrane transport proteins
- thiazides
- furosemide
- triamterene
Which Diuretics
Interactions with enzymes?
acetazolamide
Which Diuretics
Interactions with hormone receptors?
spironolactone
which diuretics have osmotic effects preventing water reabsorption?
mannitol
diuretics, what is the major EC cation?
Na+
for diuretics, movement of Na+ is controlled by
active transport via Na+-K+-ATPase activity at interstitial (blood) surface
Diuretics: At kidney, Na+-K+-ATPase produces
gradient necessary for Na+ reabsorption from the urine back into the blood
No diuretics act via
inhibition of Na+-K+-ATPase
How do diuretics work?
- Diuretics agents decrease Na+ reabsorption at various sites in the nephron
- Increased amounts of Na+ (and other ions) enter urine with H2O (passively to maintain osmotic equilibrium)
