Drugs used in the treatment of the CVS Flashcards
Describe which type of drugs are used to treat atherosclerosis
Drugs used to treat atherosclerosis involve control of blood pressure, activation of platelets and incorporation of cholesterol.
Describe types of anti platelets.
Antiplatelets: Aspirin which inhibits the production of thromboxane A2,
Clopidogrel/ticagrelor which block ADP receptor on platelet used in treatment of ACS.
Other antiplatelet agents are dipyridimole which is a phosphodiesterase inhibitor and GPIIB/IIA fibrinogen receptor antagonists.
Side effects of anti platelets
Side effects of antiplatelets: bleeding, shouldnt be underestimated particularly when combinations of antiplatelets are used. Roughly 1% annual risk of a significant bleed with a single agent, usually synergistic effect when multiple agents used rather than just simply additive. Effect will last for up to 1 week.
Describe beta blockers.
Beta blockers used widely in cardiovascular disease: reduce mortality in IHD and heart failure. Reduce symptoms in Angina, AF and SVT. Antihypertensive (2nd line now) - (multiple mechanisms of action both central and peripheral). Examples include bisprolol, carvediol, atenolol, metoprolol and propranolol.
Describe the receptors that beta blockers act on
Beta I receptors - predominant receptor in the heart - SA, AV nodes and myocardial cells. Kidneys - reduce secretion of Renin. Positive effect - slows heart rate and conduction, increases diastolic time, reduces BP, protects heart from effects of catecholamines. Negative effects - reduces contractility, high doses can lead to bradycardia and heart block.
Beta 2 receptors - smooth muscle in airways, skeletal muscle. Positive effects - reduces tremor. Negative effects - potentially lethal bronchospasm in asthmatics, vasoconstriction and PVD.
Beta I - bisoprolol, atenolol, carvediol and metoprolol.
Beta 2 - propanolol.
Describe angiotensin production
Angiotensinogen produced in liver - converted to angiotensin 1 by renin and enzyme released by the kidney in response to reduction in perfusion pressure - angiotensin 1 converted into angiotensin 2 by ACE an endothelial enzyme found in the lungs - angiotensin 2 acts on the adrenals leading to release of aldosterone.
Describe the use of angiotensin receptor blocker and ACE inhibitors.
Angiotensin converting enzyme inhibitors and angiotensin receptor antagonists (ARBS) - Antihypertensive is the first line in under 55 white/asian patient. Reduction in mortality and progression of disease in IHD, CVD and renal disease with proteinuria (particularly diabetic nephropathy). Prevent aberrant remodelling following MI and reduction in symptoms in heart failure.
Describe positive and negative effects of ACE inhibitors.
Eg Ramipril, Lisinopril, captopril, perindopril
Positive effects- Reduce blood pressure, reduce afterload on heart, prevents aberrant remodelling after MI and reduces proteinuria
Negative effects- reduces perfusion pressure in glomerulus leading to renal impairment; hyperkalaemia via effect on aldosterone levels,; cough; orthostatic hypotension
Describe positive and negative effects of ARBS
Eg, losartan, candersartan
Positive effects- Reduce blood pressure, reduce afterload on heart, prevents aberrant remodelling and reduces proteinuria
Negative effects- reduces perfusion pressure in glomerulus leading to renal impairment; hyperkalaemia via effect on aldosterone levels, No cough; orthostatic hypotension
Describe the use of aldosterone antagonists.
Spironolactone and eplenerone- used in heart failure (frequently coprescribed with ACE/ARB). Spiro sometimes used in hypertension:
-Enhanced diuretic effect, vasodilation
-Reduces mortality in IHD and Heart failure
Side effects:
-Renal impairment, hyponatraemia, HYPER KALAEMIA
-Gynaecomastia (Spiro > Eplenerone)
NSAIDS should be used with extreme caution- marked hyperkalaemia seen if AKI occurs
Describe use of Entresto
Entresto - combination of Valsartan and Sacubitil. Sacubitil inhibits the breakdown of natriuretic peptides eg ANP and BNP. Increase diuresis, natriuresis and vasodilation, indicated in symptomatic chronic HF with reduced ejection fraction. Do not co prescribe with ACE inhibitor as increased risk of angioedema.
What are the two types of calcium channel blockers.
Calcium channel blockers - antihypertensive agents, reduce symptoms in angina - both dihydropyridine and non dihydropyridine, and AF/SVT - non dihydropyridine only.
Describe dihydropyridine
Dydropyridine - block calcium channel entry into smooth muscle, cause vasodilation, less effect on myocardial pacemaking tissue e.g amlodipine, felodipine and nifedipine. Side effects - postural hypotension, peripheral oedema, tachycardia rarely bradychardia.
Describe non-dydropyridine
Non-dydropyridine - block calcium entry into smooth muscle, blocks calcium entry in the myocardial pacemaking tissue - slow SA node function and AC conduction. Eg. Verapamil and diltiazem. Side effects - bradycardia, heart block, postural hypotension and peripheral oedema.
Statins mechanism of action
Statins: primary prevention - reduce cardiovascular risk if patients 10 year risk is > 20%. Secondary prevention after cardiovascular event. Hydroxy-methyl-glutaryl Coenzyme A (HMGCoA) reductase inhibitor - rate limiting step in production of cholesterol. Eg Simvastatin, rouvastatin and atorvastatin. Side effect - muscle aches and pain but risk of myositis is low.
