Lecture 7 Alternative Treatments of Heart Failure Flashcards
How is spironolactone used to treat reduced ejection fraction in heart failure?
Improves survival in chronic heart failure, not used in cases of hyperkalaemia or renal impairment
What type of drug is spironolactone (what happens when metabolised?)?
A pro-drug
What is the active metabolite of spironolactone?
Canrenone
What is the half-life of spironolactone?
10 mins - canrenone 9-16h
What is the effect of spironolactone in the body?
Inhibition of aldosterone action on collecting duct
Important as they spare K+
Used in conjunction with other diuretics
What is ivabradine?
Used for treatment of heart failure
Inhibits funny current which stops the reduction in cardiac pacemaker activity (SAN activity)
What is the main function of ivabradine?
Slowing heart rate which inhibits the compensatory mechanisms in the heart
What are the contra-indications of ivabradine?
Myocardial infarction, cardiogenic shock, heart block, slow heart rates
What are the cautions with ivabradine?
Ineffective in atrial fibrillation, elderly and angina
What are the side effects of ivabradine?
Arrhythmias, AV block, dizziness and headache
What is Sacubitril valsartan?
Combination therapy - prodrug (sacubitril) inhibit breakdown of natriuretic peptides - increased diuresis and vasodilation and ARB (angiotensin-II blocker) - reduced BP
When is sacubitril valsartan used?
In patients not taking an ACE inhibitor or an ARB
What are the contra indications of sacubitril valsartan?
Do not use if blood pressure is <100mmHg
What are the side effects of sacubitril valsartan?
Anaemia, cough, diarrhoea, dizziness, headache, hypotension and nausea
What is hydralazine with nitrate?
Hydralazine - arterial vasodilator, reduce afterload and increase stroke volume
Nitrate - venodilator, reduce preload which reduced risk of pulmonary congestion
When is hydralazine with nitrate used?
When a patient is intolerant to ACE inhibitors ad ARBs
What are the contraindications of hydralazine with nitrate?
Acute porphyrias (blood disorders), cor pulmonale, dissecting aortic aneurysm, poor function mechanical obstruction, tachycardia
What are the side effects of hydralazine with nitrate?
Angina, headache, tachycardia, diarrhoea, dizziness, hypotension
What are the cautions of hydralazine with nitrate?
Cerebrovascular or coronary artery disease
What is digoxin?
A antiarrhythmic drug (increase vagal tone) and positive inotrope (increase intracellular Ca2+)
How does digoxin increase vagal tone?
Slows the parasympathetic nerve
What are the indications for usage of digoxin?
Chronic heart failure - improve symptoms not mortality rates
Supraventricular arrhythmias
Chronic atrial fibrillation
What is the mechanism of action of digoxin?
It blocks the Na+/K+ ATPase causing Ca2+ stores to remain in the myofibril which increases the contraction in myofibrils
What are the pharmacokinetics of digoxin?
Oral bioavailability: 75%
Onset action ~30mins
Peak effect 1-5h
Half-life 36h
Elimination ~70% renal
Narrow therapeutic range
What are the contraindications of digoxin?
Heart block
What are the cautions of digoxin?
Digitalis (foxglove) toxicity with electrolyte imbalances and recent myocardial infarction
What are the common side effects of digoxin?
Arrhythmias, cardiac conduction problems, diarrhoea, dizziness, nausea, skin reactions, vision disorders and vomiting
What is dapaglifozin used for?
Treatment of T2D and heart failure
What is the mechanism of dapaglifozin?
Blocks the SGLT2 glucose transporter in PCT (glycosuria and fluid loss)
What are the benefits of dapaglifozin?
Hemodynamic changes:
Reduction in preload and afterload
Cardiac function improves
What are the adverse effects of dapaglifozin?
Rare severe ketacidosis
What are the contraindications of dapaglifozin?
Diabetes ketoacidosis
What are the cautions of dapaglifozin?
Elderly, hypotension, risk of volume depletion
