CVS Flashcards
What types of drugs reduce the symptoms of cardiovascular disease?
ACE inhibitors Beta blockers (anti-arrhythmic) Ca channel blockers Diuretics Nitrates
What types of drugs prevent cardiovascular disease?
Anti-platelet drugs
Lipid lowering drugs
Anti-arythmics
What are antiplatelet drugs?
Drugs that don’t allow the platelets to stick together easily.
Have to reduce dose when tooth is being extracted as they cause prolonged bleeding.
e.g. aspirin, clopidogrel, dipyridamole
What is the function of aspirin?
Anti-platelet drug
Inhibits platelet aggregation
Alters the balance between thromboxane A2 and prostacyclin
Irreversible effect on the platelet (lasts 7-10 days)
What is the function of clopidogrel?
Inhibits ADP induced platelet aggregation
What is the action of lipid lowering drugs?
HMG CoA Reductase Inhibitors (statins)
Inhibit production of cholesterol from cholesterol precursors (cholesterol synthesis takes place in the liver)
As a result they reduce the total cholesterol and LDL cholesterol
e.g. simvastatin, atorvastatin
What is the action of anti-arrhythmic drugs?
Slow down heart conduction so the heart remains at a safe level. Prevent unusual heart rhythms which can lead to heart attacks.
a. k.a. Beta blockers
e. g. atenolol, propanolol
What is the downside of using antiarrhythmics?
Blocks beta receptors in the lungs - making asthma worse
Blocks renal B1 receptors - release of renin blocked
Reduce heart efficiency - make heart failure worse, reduced contractility
What is the action of atenolol?
Beta blocker
Selective B1 only - heart and kidney
What is the action of propanolol?
Beta blocker
Non-selective B1 and B2 - lungs, liver, vascular smooth muscle & skeletal muscle
How would you calculate cardiac output?
Stroke Volume x Heart Rate
What is meant by total peripheral resistance?
The combined resistance of all the systemic blood vessels
What is the action of diuretics?
Increase salt and water loss:
- reduce plasma vol
- reduce cardiac workload
- heart copes better as it does less work
e. g. thiazide diuretics (bendrofluazide), loop diuretics (frusemide)
What are the side effects of diuretics?
Can lead to Na+/K+ imbalance if not monitored carefully
What is the action of nitrates?
Short acting or long acting
Dilate veins - reduce preload to heart
Dilate resistance arteries - reduce cardiac workload, reduce cardiac oxygen consumption
Dilate collateral coronary artery supply - reduce anginal pain
*Inactivated by first pass metabolism
What methods of administration can be used for nitrates?
Sublingual, transdermal, intravenous
Inactivated by first pass metabolism so must enter into the systemic circulation.
What are short acting nitrates?
Glyceryl trinitrate (GTN) Works in minutes
What are long acting nitrates?
Isosorbide mononitrate (skin patch) Works for many hours
What are the possible side effects of nitrates?
Headache
What is the action of calcium channel blockers?
Block calcium channels in smooth muscle.
Some are more active on the heart muscle e.g. verapamil
Some are more active on peripheral blood vessels e.g. nifedipine
What is the action of verapamil?
Slows conduction of pacing impulses in the heart (AV node conduction) therefore decreasing the heart rate
Ca channel blocker
What is the action of nifedipine?
Relaxation and vasodilation of peripheral blood vessels
Ca Channel blocker
What are the side effects of calcium channel blockers?
Those acting on peripheral blood vessels can cause gingival hyperplasia
What is the action of ACE inhibitors?
Inhibit conversion of angiotensin I to angiotensin II
Prevents aldosterone dependent reabsorption of salt and water
Reduces blood pressure (due to b.v. dilation & decrease of water)
e.g. analapril, ramapril, lisinopril
What are the possible side effects of using ACE inhibitors?
Cough
Hypertension
What problems are caused by blood vessel narrrowing?
Inadequate oxygen delivered to tissues
‘cramp’ in affected tissue/muscle
No residual deficit at first
What problems are caused by blood vessel occlusion?
No oxygen delivery - results in tissue death
More severe pain
Loss of function of tissue
What is coronary artery disease?
When the heart’s blood supply becomes blocked due to build up of fat
Heart is supplied by - right coronary artery, circumflex coronary artery and the left anterior descending coronary artery