Clinical Pharmacology of Stable Coronary Heart Disease and Angina Flashcards
What is silent ischaemia?
No pain
Who is often effected by this?
Diabetics
What are the risk factors of stable angina?
- Hypertensive
- Male
- Hyperlipidaemia
- Hyperglycaemia
- Male
- Post-menopausal female
What is hyperlipidaemia a disease of?
Muscular arteries —coronary
cerbral
What is a fatty streaks?
Subendothelial accumulation of large foam cells (derived from macrophages plus SM cells) Filled with lipid
What a fibrous plaque?
- More advanced and the cause of disease
- Develop from fatty streaks
- Projects into arterial lumen
- Reduced blood flow
Where are the changes taking place when an artery becomes atherscerlosed?
intimal layer
What accumulates in an atheroma?
Monocytes, lymphocytes, foam cells and connective tissue
What is the origin of of the foam cells?
Mostly muscle origin
What is SCAD?
Stable coronary artery disease
Why does SCAD arise?
mismatch between myocardial blood/oxygen supply and demand
What is demand ischaemia?
Ischaemia during stress
What determines demand?
- Heart rate
- Systolic blood pressure
- Myocardial wall stress
- Myocardial contractility
What is supply ischaemia?
Ischaemia at rest
Determinants of supply?
- Coronary artery diameter and tone
- Collateral blood flow
- Perfusion
- Heart rate
How do drugs decrease myocardial oxygen demand?
Reducing cardiac workload
- Reduce heart rate
- Reduce myocardial contractility
- Reduce afterload
Name the rate limiting drugs for SCAD?
- Beta-adrenoceptor antagonists
- Ivabradine
- Calcium channel blockers
Name the vasodilations used to teat SCAD
Calciumchannel blockers
Nirates
What do beta blockers act on?
- Heart rate
- Contractility
- Systolic
What do beta blockers do to subendocardium?
Allows improved perfusion by increasing diastolic perfusion time
name 2 beta blockers?
- Bisoprolol
- atenolol
What are beta blockers?
They are reversible anatgonists of the B1 and B2 receptors
What do beta blockers do?
- decrease the heart rate
- Decrease contracility
- Decrease CO
- Decrease BP
- Protect cardiomyocytes from oxygen free radicals formed during ischaemic episodes
What is rebound phenomena?
-Sudden cessation of beta blocker therapy may precipitate myocardial infarction
What are the contradictory conditions to prescribing beta blockers?
- Asthma
- peripheral vascular disease
- Raynauds syndrome
- Heart failure (on sympathetic drive)
- Bradycardia/Heart block-over do
What is raynauds syndrome?
smaller arteries that supply blood to your skin narrow, limiting blood circulation to affected areas (vasospasm).
What are the adverse drug reactions of beta blockers?
- Tiredness/fatigue
- Lethargy
- Impotence
- Bradycardia
- Bronchospasm
What can happen when beta blockers are given with other rate limiting drugs ]?
Bradycardia
Name two rate limiting drugs?
- verapamil
- diltiazem
When can beta blockers cause cardiac faiure?
When used with negatively ionotropic agents
What can beta blockers mask?
hypoglycaemic actions of insulin or oral hypoglycaemics
Name 3 calcium channel blockers?
Diltiazem
Verapamil
Amlopidpine
how do CCB`s work?
Prevent clacium influx into myocytes and smooth muscle lining arteries and arterioles by blocking the L-type calcium channel
What are the two types of calcium blockers?
- Rate limiting (dilitazem verapamil)
- Vasodilating (nifedipine or amlodipine)
What can cause MI strokes if given rapidly?
Nifedipine immediate release
What are some adverse drug reactions to CCB`s?
- Ankle oedema
- headache
- Flushing
- Palpitaion
Name 3 nitrovasodilators?
- Glyceryl trinitrate
- Isosrbide mononitrate
- Isosorbide dinitrate
How can you administer GTN?
- Sublingual
- Buccal
- Transdermal
How can you administer isosorbide mono/dinitrate?
-Sustained release formulation,tablets
What can GTN cause?
Syncope
How do nitrovasodilators relax muscle?
by releasing NO which then stimulates the release of cGMP which produces smooth muscle relaxation
How do nitrovasodilators reduce myocardial oxygen consumption?
Reduce preload and after load
How do nitrates relieve angina?
- Arteriolar dilation
- Venodilation (less preload less work)
- Revlieving coronary vasospasm
- Redistributing myocardial blood flow to ischaemic areas of the myocardium
Do nitrates reduce morbidity?
NO evidence of this
What adverse drug reactions to nitrates?
- Headache
- Hypotension
Name one potassium channel opener?
Nicorandil
How do potassium channel openers work?
- Activate “silent” potassium channels
- Then entry of potassium into cardiac myocytes inhibits the calcium influx and so has a negative inotropic action
What level of treatment is potassium channel openers and why?
- Third line
- Bowel ulceration
What does Ivabradine do?
Is a selctive sinus node If channel inhibitor
- Slows the diastolic depolarisation slope of the SA-node
- Reduces heart rate and therefore O2 demand
Name an antiplatelet agent
-Low does aspirin
How does aspirin work?
inhibits platelet thromboxane production
What does thromboxane do?
Stimulate platelet aggregation and vasoconstriction
What is the most common cause of admission with a GI bleed
Low dose aspirin
When should aspirin be given?
When HR is greater then 70 bpm
How does clopidogrel work?
Inhibits ADP receptor activated platelet aggreagtion
Name 3 cholesterol lowering agents?
Simvastatin
Pravastatin
Atorvastatin
What do cholesterol lowering drug inhibit?
HMG coA reductase
What is the regime in order for treating SCAD?
-Beta blockers
-rate limiting CCB
-Dihydropiridine CCB
-Ivabradine
-Aspirin
-Statin
-Nitrate
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