Congestive Heart Failure Drugs

Question 1

Groups of drugs used to treat CHF

Answer 1

1) Beta Agonists (positive inotropic)
2) Beta Blockers
3) Diuretics
4) ACE Inhibitors (angiotensin converting enzyme)
5) Vasodilators

Question 2

Positive Inotropic Drugs (beta agonists)

Answer 2

Digoxin 
Inamrinone 
Milrinone 
Dobutamine 
Dopamine

Question 3

Digoxin Chemistry and Pharmacokinetics

Answer 3

Steroid nucleus. 
Great bioavailability oral + IV 
HALF LIFE ~40hrs 
Narrow therapeutic index 
Large volume of distribution

Question 4

Digoxin MOA and Use

Answer 4

Rx: CHF + A fib
MOA: inhibits the Na+/K+ ATPase pump => Increased Intracellular Ca2+
= gradual increase in cardiac contractility
*NO effect on morbidity and mortality

Question 5

Digoxin Adverse Rxn

Answer 5

Vagomimetic Effect - slows SA node and conduction velocity at AV. Decrease refractory period of tissue.

• heart- AV block, v-tach, v fib, tach arrhythmia.
• nausea, visual disturbances- Yellow Halo

Question 6

Digoxin drug interactions

Answer 6

K+ - hypokalemia, arrhythmias
Ca2+ - increase toxicity
Mg2+ - reduces toxicity
*Quinidine = increase digoxin levels via decreased renal clearance!

Question 7

Inamrinone, Milrinone

Answer 7

positive inotropic drug
Acute CHF, IV administration
=phosphodiesterase (PDE3) inhibitors of cAMP cGMP.
= increased force of contractility and vasodilation
adverse rxn- arrhythmias

Question 8

Dobutamine

Answer 8

positive inotropic drug 
Acute CHF
=selective beta-1 adrenoceptor agonist
= inc force of contraction
*Adverse rxn: Tachyphlaxis (rapid tolerance)!

Question 9

Dopamine

Answer 9

positive inotrope
Acute CHF or renal failure, shock, cardiac arrest.
= inc release of NE , stimulates beta-1 adrenoceptors (positive inotropic effect) and dopamine receptors (renal vasodilation).

Question 10

Q: A patient taking digoxin is about to receive atropine for a new condition. An effect of digoxin blocked by atropine is…

Answer 10

A: Increased PR interval

Question 11

Diuretics and MOA

Answer 11

Hydrochlorothiazide
Furosemide
Spironolactone
MOA: increase excretion of sodium and water, reduce edema

Question 12

Hydrochlorothiazide

Answer 12

mild to moderate CHF

-can result in Hypokalemia, need K+ supplement.

Question 13

Furosemide

Answer 13

high ceiling ‘loop’ diuretic used in treatment of acute CHF and severe chronic CHF.
-may cause hypokalemia

Question 14

Spironolactone (& Epterenone)

Answer 14

= aldosterone antagonist (K+ sparing diuretic)
CHRONIC CHF
***Reduced morbidity and mortality when used with ACE inhibitors
-may cause hypErkalemia

Question 15

Angiotensin Converting Enzyme (ACE) inhibitors

Answer 15

Captopril, Enalopril, Lisinopril, Ramipril

Angiotensin II receptor (ATI) Antagonist- Losartan (no dry cough)

Question 16

ACE Inhibitors MOA

Answer 16

inhibit the production of angiotensin II, thus reducing sympathetic activity and aldosterone release
= reduces afterload and decrease remodeling.
(dry cough)

Question 17

Vasodilators

Answer 17

Nesiritide, Isosorbide Dinitrate (nitrate), Hydralazine

Question 18

Nesiritide

Answer 18

Vasodilator- increases cGMP to dilate veins and arteries. in acute CHF

Question 19

Nitrates

Answer 19

increase cGMP and are VENOdilators, reducing preload. Given sublingually
(-) Reflex tachy, tolerance, Headache!!

Question 20

Hydralazine

Answer 20

= arteriolar vasodilator.

May cause tachycardia, flushing, headache, and lupus-like syndrome.

Question 21

Beta-Adrenergic Receptor Blockers

Answer 21

Bisoprolol (B1), Carvedilol (B1,B2,A), Metoprolol (B1)
patients with STABLE CHF (otherwise decompensation may occur)
***reduce mortality

Question 22

Treatment of Chronic Heart Failure (from less severe to most severe)

Answer 22

1) reduce risk factors
2) ACE inhibitors, Beta Blockers, Diuretics
3) + aldosterone agonists, digoxin, nitrate, cardiac resynchronization
4) Transplant

Question 23

Treatment of Acute Heart Failure

Answer 23

coronary angioplasty + loop diuretics, inotropic agents and vasoactive drugs