Flashcards in Pharmacology: Katzung Drugs used in heart failure Deck (41)
Why are diuretics used to treat hear failure?
Because they reduce fluid retention and blood volume.
Which diuretics are commonly used in heart failure?
Furosemide, Hydrochlorothiazide, Spirinolactone.
What is the MOA of furosemide?
Furosemide inhibits the Na/K/2Cl transporter in the TALH. This creates a powerful diuretic action. It also has a vasodilating effect on the pulmonary vessels.
What are the clinical applications for furosemide?
(1) Acute/chronic heart failure
(2) acute pulmonary edema
(3) other edematous conditions
What adverse effects are associated with furosemide?
What is the MOA for hydrochlorothiazide?
Hydrochlorothiazide inhibits the Na/Cl transporter in the distal tubule. This reduces preload and edema by a modest diuretic action.
What are the clinical applications for Hydrochlorothiazide?
(1) Mild chronic heart failure
(2) Chronic renal stones
(3) Nephrogenic diabetes insipidus
What are the adverse effects associated with hydrochlorothiazide?
(3) metabolic alkalosis
What is the MOA of spirinolactone?
Spirinolactone is an antagonist of the Aldosterone receptor in the kidney. Causes diuresis be preventing up regulation of Na channels for Na reabsorption.
What angiotensin inhibitors are used to treat heart failure?
Captopril, Benazepril, enalapril,
Why are angiotensin inhibitors used to treat hear failure?
They reduce afterload, salt, and water retention.
What is the MOA of ACE inhibitors like captopril?
Captopril and other ACE inhibitors block angiotensin converting enzyme thus preventing the conversion of Angiotensin I to angiotensin II. Decrease in angiotensin II decreases vascular tone and aldosterone secretion.
What are the clinical applications for the ACE inhibitors?
(1) Heart failure
What are the adverse effects associated with the ACE inhibitors?
contraindicated in Pregnancy
Lower angiotensin II
Why are positive inotropic agents used to treat heart failure?
Positive inotropic agents are used to treat heart failure when is particularly severe and an increase in cardiac output is necessary to maintain perfusion
What positive inotropic agents are used to treat heart failure?
Digoxin (cardiac glycoside)
What is the MOA of Digoxin?
Digoxin inhibits the Na+/K+ ATPase. This increases intracellular Na+ which decreases Ca expulsion. Increase intracellular Ca causes increased cardiac contractility.
What are the clinical applications for digoxin?
(1) heart failure
(2) Nodal arrythmias
What are the adverse effects associated with digoxin?
(4) visual changes (rare)
What is the MOA of dobutamine?
Dobutamine is a beta 1 selective sympathomimetic the increases cAMP and thus increases the force of contraction.
What are the clinical applications for dobutamine?
(1) Acute heart failure
What are the adverse effects associated with dobutamine?
Why are beta blockers used to treat Heart failure?
beta blockers are used to treat heart failure because they decrease excess sympathetic stimulation.
Which beta blockers are used to treat heart failure?
What is the mechanism of action for Carvedilol, metoprolol, and bisoprolol?
They are beta receptor blockers, however, their effect on heart failure is poorly understood. It is possible that they decrease remodeling.
Why are vasodilators used to treat heart failure?
Vasodilators reduce preload and afterload.
Which vasodilators are used to treat heart failure?
Hydralazine + isosorbide dinitrate
What is the MOA of Nitroprusside?
Nitroprusside causes massive powerful vasodilation which reduces preload and after load.
What are the clinical applications for Nitroprusside?
Acute severe decompensated heart failure