Pharm: CHF drugs

Question 1

What is acutely decompensated CHF?

Answer 1

Acute CHF superimposed on the setting of chronic CHF

Question 2

What are the treatment objectives for acute CHF?

Answer 2

Early recognition and treatment
Decrease symptoms
- Reduce pulmonary congestion: loop diuretics, venodilators, nesiritide
-Increase CO:
–Increase contractility: beta blockers, phosphodiesterase inhibitors
–Reduce afterload: nitroprusside

Question 3

Why are diuretics useful for acute CHF?

Answer 3

Reduced preload and pulmonary venous pressure

Increases oxygenation

Question 4

What diuretics are used to treat acute CHF?

Answer 4

Furosemide

Thiazides

Question 5

What is the major effect of nitrates?

Answer 5

Dilation of venous capacitance vessels

Question 6

What is Niseritide and what is it used for clinically?

Answer 6

Niseritide is a recombinant form of BNP

Used to treat CHF by inducing vasodilation and natriuresis

Question 7

What inotropic agents are used to treat CHF?

Answer 7

Beta agonists: dobutamine, dopamine, isoproterenol and norepinephrine
Phosphodiesterase inhibitors: inamrinone, milrinone
*These drugs increase cAMP levels

Question 8

What are the actions of cAMP in cardiac muscle?

Answer 8

Opens L-type Ca2+ channels
Increased reuptake of Ca into SR
Increased pacemaker current
Increased rate of conduction

Question 9

Why are vasodilators beneficial for CHF patients?

Answer 9

Reduced afterload due to reduced systemic vascular resistance allows for increased SV and CO

Question 10

Are Calcium channel blockers used for CHF patients?

Answer 10

No. Contraindicated for CHF due to negative inotropic effects

Question 11

What are the non-pharmacological therapies for acute CHF?

Answer 11

PCI/surgical therapy: revascularization and/or valve repair
Ultrafiltration
Intra-aortic balloon pump
Ventricular assist devices

Question 12

What are the treatment objectives for chronic CHF?

Answer 12

Early recognition of ventricular dysfunction
Prevent ventricular remodeling
Decrease symptoms: decrease congestion, increase CO
Prolong survival

Question 13

What drugs prevent ventricular remodeling?

Answer 13

ACE inhibitors, ARB’s, LCZ696
Beta blockers
Aldosterone antagonists (spironolactone)

Question 14

What is the mechanism of action of digitalis glycosides?

Answer 14

Inhibit the Na/K ATPase pump which increase the Na inside the cell, this leads to increased activity of the Na/Ca exchanger, bringing more Ca into the cell and more Ca stored in the SR

Question 15

What are the mechanical effects of digitalis glycosides?

Answer 15

Increased contractility

• increased velocity of shortening, force of contraction, ventricular emptying
• Decreased ESV and EDV

Question 16

What are the systemic effects of digitalis glycosides?

Answer 16

Increased CO
Increased renal perfusion
Decreased sympathetic tone

Question 17

What are the side effects of digitalis?

Answer 17

VERY NARROW THERAPEUTIC WINDOW

Causes DADs and abnormal automaticity, arrhythmias

Question 18

What is the difference in vasodilator drugs used for acute versus chronic CHF?

Answer 18

Acute CHF drugs (nitroprusside, nitroglycerin) are given IV and have rapid onset of action
Chronic CHF drugs (ACEi’s, ARBs, hydralazine, minoxidil, prazosin, LCZ696) are given orally and have slower onset of aciton

Question 19

What is the mechanism of action for ACE inhibitors preventing ventricular remodelling?

Answer 19

1) Ang II is a cardiomyocyte growth factor and fibroblast mitogen
2) Inhibit RAA system
3) Decreased wall stress

Question 20

What is LCZ696?

Answer 20

A combination of valsartan (ARB) and sacubitril (Neprilysin inhibitor)
Valsartan blocks the AT1a receptor on cardiac and vascular smooth muscle
Sacubitril causes vasodilation and reduced ECF volume via sodium excretion

Question 21

How are beta blockers useful for chronic CHF treatment?

Answer 21

Increased survival due to reduced LV deterioration

Mechanism: reduced HR and blocking deleterious effects of chronic sympathetic stimulation

Question 22

What specific beta blockers are used for chronic CHF therapy?

Answer 22

Carvedilol
Metoprolol
Bucindolol

Question 23

What are the nonpharmacological treatments for chronic CHF?

Answer 23

Surgical therapy
Left ventricular assist devices
Biventricular pacing
Cardiac transplantation