Diuretics and RAAS antagonists Flashcards
3 goals of HF management with pharmacotherapy
- Reduction of congestion
- Modulate neurohormonal activation
- Improve flow
Which diuretics are the most efficacious, why?
Loop
Which classes of drugs are K+ sparing? Na + sparing? K+ wasting?
Na+ sparing = Aldosterone
K+ wasting = Loop and Thiazides
K+ sparing = Aldo-antagonists, ACE-I, and ARB
In HFrEF acute conditions, which drugs would you use?
IV diuresis!!!
Nitrates (if BP allows)
CPAP/BiPAP (if SOB)
Pressors (if ↓↓↓CO, shock
In HFpEF acute conditions, which drugs would you use?
IV diuresis!!!
Nitrates (if BP allows)
CPAP/BiPAP
Diuretics used to treat what?
Volume overload
(SV-Vntricular EDP grap gets moved to left)
Diuretics will: ↑ Salt (+Water) Excretion → ↓ Intravasc Fluid Vol → ↓ Venous congestion → ↓ Dyspnea, Edema
Lowers preload (LVEDP)
Are diuretics used chronically or acutely?
can be both
Most common diuretic
Furosemide
- Torsemide or bumetanide have more reliable absorption
Describe when/how you would initially use ACEIs
Started during or after optimization of diuretic therapy at low doses
What do ACEIs produce?
Produce vasodilation
↓ aldosterone activation
Plus antiremodeling effect
True/False, ARBs used in conjuction with ACEIs will benefit from the dual therapy
NO!
No apparent benefit from dual therapy
What drug is added to therapy for LVEF < 30-35%, optimized on ACEI/ARB and β-blocker therapy
Aldosterone Antagonists
- ACEI/ARB aldosterone block is incomplete
what type of aldosterone antagonist is preferred?
Spironolactone preferred if tolerated - if endocrine side effects (gynecomastia) can use eplerenone
Diuretic Agents you would be stupid not to know
#11: Hydrochlorothiazide #14: Furosemide (Lasix®) #70: Spironolactone (Aldactone®)
Nearly all diuretic agents exert their effects at______ surface of renal tubule cells.
luminal (urine)
Na+ is the major extracellular cation and its movement between compartments is controlled by regulated active transport via ________ activity at the _______ surface
Na+-K+-ATPase
interstitial (blood)
Compensatory changes in HF
↓ CO →
- ↑ Sympathetic discharge
(baroreceptor response) - ↑ Renin release
(RAAS response) - Na+ reabsorption → ↑ fluid retention
(remodeling caused by AII can cause chronic harm)
Diuretic mechanism of:
thiazides, furosemide, triamterene
Interactions with membrane transport proteins
Diuretic mechanism of:
(acetazolamide)
or
(spironolactone)
Intxn of enzymes (acetazolamide)
or
hormone receptors (spironolactone)
Diuretic mechanism of:
Mannitol
Osmotic effects preventing water reabsorption
True / False, diuretics act via inhibition of Na+-K+-ATPase
False
Diuretic agents decrease Na+ reabsorption at various sites in the nephron
K+ sparing diuretics do what?
K+ wasting diuretics do what?
- examples
K+ sparing diuretics
- decrease K+ excretion in collecting duct
K+ wasting diuretics
- increase K+ excretion in ascending LOH
K+ sparing diuretics
- examples
Aldosterone antagonists
K+ wasting diuretics
- examples
Loop agents
Thiazides
Loop diuretic examples
- what do they do?
- examples
Inhibit NaCl transport (Na+-K+-2Cl–transporter)
Furosemide
Bumetanide
Torsemide
Loop diuretics Associated with increase in ____and ___ excretion (diminish lumen-positive potential)
Mg++, Ca++
If Loop diuretics such as Furosemide has a lack of response, what drugs can you switch to?
What about if there is a sulfa allergy?
Switch to bumetanide or torsemide –> more reliable bioavailability and longer duration of action
Ethacrynic acid can be used if sulfa allergy
Which aldosterone antagonist improves survival in some pts with systolic HF?
Spironolactone
What type of drug is most efficacious in HF?
Loop diuretics
