Cardiovascular modulators Flashcards
What are the compensatory mechanisms of cardiac disease?
Activation of sympathetic nervous system
Renin-angiotensin-aldosterone system (RAAS)
How does the sympathetic nervous system affect cardiac disease?
Increases HR and contractility - beta receptors
Vasoconstriction - alpha receptors
How does the renin-angiotensin-aldosterone system (RAAS) affect cardiac disease?
Increased water retention
Increased blood volume - preload
Vasoconstriction - afterload
What is the main loop diuretic drug?
Furosemide
What do loop diuretics (furosemide) act on?
Inhibit NaKCl symport at the loop of henle
What effect do loop diuretics have on the body?
Inhibit resorption of Na
VASODILATION
Activate RAAS
Reduces preload Stabilises
What is a side effect of loop diuretics?
Extreme loss of electrolytes
What is an alternative to furosemide?
Torasemide
What is the main drug of thiazide diuretics?
Hydrochlorothiazide
What do thiazide diuretics act on?
Inhibit KCl symport at distal convoluted tubule
What effect do thiazide diuretics have on the body?
Inhibit resorption of Na but increase K excretion
What are side effects of thiazide diuretics?
Hypokalaemia
Hypercalcemia
What is the main potassium-sparing diuretic 1 drug?
Spironolactone
What do potassium-sparing diuretics 1 act on in the body?
Mineralocorticoid receptor inhibiting aldosterone
What effect do potassium-sparing diuretics 1 have on CHF?
Acts on myocardium to inhibit aldosterone-mediated fibrosis and remodelling
ANTI-REMODELLING
Weak diuretic effect
What are the side effects of potassium sparing diuretics 1?
Hyperkalaemia
Hyponatremia
Reduced ECF volume
What is the main potassium-sparing diuretic 2 drug?
Amiloride
What do potassium-sparing diuretics 2 act on in the body?
Inhibit renal epithelial sodium channel
What effect do potassium-sparing diuretics 2 have on CHF?
Inhibit NaCl resorption, stimulate K+ retention
What are the side effects of potassium sparing diuretics 2?
Hyperkalaemia
What are carbonic anhydrase inhibitors used for?
Glaucoma
What are osmotic diuretics (mannitol) used for?
Increased intracranial pressure
What is the main positive inotropic drug?
Pimobendan
Dobutamine
What method of action does pimobendan/positive ionotropic drugs have?
Sensitises troponin to calcium - increases CONTRACTILITY
Vasodilation
What is pimobendan used for?
Congestive heart failure
Mitral valve disease
Dilated cardiomyopathy
What is dobutamine used for?
Severe CHF with hypotension
What is the main RAAS modulator?
Benazepril
What are RAAS modulators mode of action?
ACE inhibitors
Reduce preload/afterload***
Anti-remodelling
Anti-adrenergic
What are the side effects of ACE inhibitors?
Azotemia, hyperkalaemia, hypotension
What is the main beta blocker?
Atenolol
What mode of action do beta blockers have?
Reduce HR and Contractility – reduce tachycardia and arrhythmias
When are beta blockers used?
Obstruction of ventricular outflow
What are the 4 main drugs for congestive heart failure?
Furosemide
Spironolactone
Pimobendan
Benazepril
What drug is used just for vasodilation?
Hydralazine
