Pharmacology of Stable Coronary Disease Flashcards
Describe stable angina?
Predictable chest pain precipitated by exercise or emotional stress which increases with myocardial oxygen demand
What are the non-modifiable risk factors?
Family history, post-menopausal female, other arterial disease and male
Describe modifiable risk factors?
Hypertension
Smoking
Diabetes
Hyperlipidaemia
How does angina arise?
Mismatch between myocardial oxygen supply and the myocardial demand
Increase myocardial blood flow and reduce the demand
What increases myocardial demand?
HR, preload, afterload, myocardial contractibility, relaxation and wall stress
How do we treat?
Relieve symptoms
Slow/ halt the disease process
Prevent myocardial infarction
Prevent premature death
What are rate limiting drugs used for relieving symptoms?
Beta-adrenoreceptor antagonist
Calcium channel blocker (L-type)
Ivabradine (f-channels)
What are some vasodilators which are used to relieve symptoms?
Nitrates
Calcium channels blockers
Potassium channel activator
What is the sodium channel activator used to relive symptoms?
Ranolazine
What are some antiplatelets used for disease modification?
Aspirin
Clopidogrel
Ticagrelor
Prasugrel
What are some cholesterol lowering drugs used for disease modication?
HMG-CoA reductase inhibitors
Fibrates
PCSK-9 inhibitors
What is the mechanism of action for beta-blockers?
reversible inhibitor of beta 1 and beta 2 receptors
Blocks the sympathetic system
Can be selective or non-selective
What are the side effects/ cautions for beta-adrenoreceptor antagonists?
Asthma, peripheral vascular disease, acute heart failure and bradycardia or heart block
What are cardio selective and non selective beta blockers?
Cardio selective - bisoprolol, metoprolol, atenolol
Non-selective - Carvedilol, propranolol
What are the benefits of beta blockers?
HR reduced so reduced workload
Decreased contractibility
Improves relaxation
Increases diastolic perfusion time
Reduces rate of ischaemic events and mortality
What is the mechanism of action for calcium channel blockers?
Prevent calcium influx into myocytes and smooth muscle arteries by blocking L type Ca channels
Dihydropyridine used to relax smooth muscle
Non-dihydropyridine mostly reduce HR
Act on Alpha 1 subunit
What are the benefits for calcium channel blockers?
HR reduced
Reduce contractibility, afterload (DHP) and perfusion time is increased
What are some side effects of calcium channel blockers?
Bradycardia/heart block and reduced LV function
Also reduced hypotension
What is the mechanism of action of nitrates?
NO mediated smooth muscle relaxation, non-selective, long acting preparations are most effective and sublingual for acute - spray
What are side effects of nitrates?
Severe aortic stenosis
Hypotension
Headache
What are the benefits of nitrates?
reduced preload and afterload so myocardial workload is reduced
Improved coronary flow as vasodilation
What is the mechanism of action for Nicorandil - potassium channel activator?
Activates ATP sensitive potassium channels causing potassium influx
Resultant inhibition of Ca influx - negative inotrope and smooth muscle relaxation
What are the side effects of Potassium channel activators?
Hypotension and GI ulceration
What is the mechanism of action for Ivabradine - funny channel inhibitor?
Inhibits the funny channels located in SA node and only work when patient is in sinus rhythm
What are the side effects of Ivabradine?
Bradycardia and SA node disease
What are the benefits of Ivabradine?
HR is reduced when sinus rhythm
Reduces rates of infarction
What is first step in treatment?
BB or CCB
What is the mechanism of action for sodium channel drugs - Ranolazine?
Inhibits late sodium current in myocardial cells and inhibits rapid phase of potassium rectifier current
Na+/K+ balance across membrane
Reduces intracellular calcium
What the benefits of sodium channel late inward current?
Reduced O2 demand due to reduced wall stress - easier to perfuse microcirculation
Possible antiarrhythmic effects
What are statins used?
Atorvastatin
Simvastatin
Rosuvastatin
What is involved in slow disease progression?
Statins, Reduced cholesterol absorption, fibrates
What are the benefits of lipid lowering therpaies?
Reduced rate of MI and plaque stabilisation
Describe thromboxane A2 inhibitor
Antiplatelet
Inhibits platelets activation
Aspirin
Describe P2Y12 inhibitors
Inhibits platelet activation via ADP mediated pathway
What is the benefit of aspirin?
Reduces adverse cardiac events like MI or death when used properly
Why is aspirin not recommended for prophylaxis?
Associated with bleeding GI risk
Proton pump inhibitor used as protection to reduce acid
