Pharmacology of Heart Failure Drugs Flashcards
What are examples of loop diuretics?
Furosemide
Bumetanide
Torsemide
When are loop diuretics used?
Pulmonary oedema = acute LV failure
Chronic heart failure
How are loop diuretics normally administered?
IV
What do loop diuretics do?
Reduce electrolyte reabsorption in thick ascending limb of loop of Henle
What do loop diuretics target in loop of Henle?
Target Na+K+Cl- co-transporter
Traps Na+K+ = attracts H2O
= passes into urine
What is 1st line treatment for HF?
ACEi with beta-blocker
What are examples of ACEi?
Ramipril
Catopril
Enalapril
Lisinopril
What can be used as an alternative of ACEi?
ARBs
BUT not as effective
What are examples of ARBs?
Candesartan
Losartan
What are the preferred beta-blockers for HF?
Bisoprolol
Carvedilol
Nebivolol
What is the mechanism of action for beta-blockers?
Inhibits beta1 receptors
Blocks effects of adrenaline + noradrenaline
Inhibits release of renin
What do beta-blockers do overall?
Slows HR + reduces contractility
= reduces workload of heart
= reduces strain
What is Ivabradine used to treat?
Angina
Mild to severe chronic heart failure
What is Ivabradine used as an alternative for?
Beta-blockers
BUT can be used alongside
What is Sacubitril Valsartan?
ARB combined with a prodrug
What does Sacubitril (prodrug part) do?
Inhibits breakdown of naturally occurring diuretic peptides
When is Sacubitril Valsartan used?
In patients not currently taking an ACEi or ARB
When is Hydralazine with nitrate used?
Patients intolerant to ACEi + ARBs with moderate to sever HF
What is Hydralazine?
Arteriolar dilator
What does arterial vasodilators do?
Reduce afterload
Increase SV + CO
What are nitrates?
Venodilators
What does venodilators do?
Reduce preload
Reduce risk of pulmonary congestion
What are the side effects of Hydralazine with nitrate?
Headaches
Tachycardia
Irregular heartbeat
What is digoxin?
Antiarrhythmic drug
Positive inotrope
What does an antiarrhythmic drug do?
Increase vagal tone to heart
= vagus nerve decreases HR
What does a positive inotrope do?
Increase Ca2+
= increases force of contraction
How does Digoxin work as a positive inotrope?
Blocks Na+K+-ATPase
= less Na+ pumped out
= accumulates into cell
=Na+/K+ exchanger switched off
= more Na+ inside = more Ca2+ left behind
= more available for more forceful contraction
What is the main problem/cautions with Digoxin?
Toxicity
When is spironolactone used?
When patient does not respond to 1st line treatment
= it’s added on
What is spironolactone?
K- sparing diuretic
What does spironolactone do?
Blocks aldosterone-induced production of Na+ transport proteins in DCT
= reduces ability to absorb Na+
= causes Na+ + H2O loss
