Cardiovascular Drugs Flashcards
What drugs are used to prevent further CV disease
Anti platelet drugs Statins Anti-arrhythmics Anticoagulants Diuretics Ace-inhibitors Beta-Adrenergic Blockers
What drugs are used to reduce symptoms of current CV disease
Diuretics
Anti-arrhythmics
Nitrates
Calcium channel blockers
Give examples of anti platelet drugs
Aspirin
Clopidogrel
Dipyridamole
What is the function of Aspirin
Inhibits platelet aggregation, alters balance between Throboxane A2 and Prostacyclin
What is the function of Clopidogrel
Inhibits ADP induced platelet aggregation
What is the function of Dipyridamole
Inhibits platelet phosphodiesterase
What are other functions of anti platelets
Significantly reduce the chance of heart attack and stroke in the at risk population
Prolong the bleeding time following dental extraction
Give examples of new antiplatelet drugs and when are they used
Prasugrel, Ticagrelor
Only used in conjunction with aspirin
Only licensed for ACS
Give examples of oral anticoagulants
Warfarin Rivaroxiban Apixaban Dabigatran Edoxaban
Describe how oral anticoagulants work
By reducing the activation of the clotting cascade, they reduce the amount of fibrin formed and therefore clot stability
Once platelet has formed it will not stabilise properly as fibrin will not be deposited on the surface
Describe the bleeding pattern with oral anticoagulants
Typical bleeding pattern is to stop bleeding as normal but bleeding will continue after a few hours
Does not affect bleeding time
Describe how warfarin works
Inhibits synthesis of vitamin K dependent clotting factors
Factor 2,7,9,10 slow over 2 days as the supplies stored from liver are still in circulation
Immediate effect on protein C and S as it inhibits their function - they will not inhibit the inhibition of clotting
What is the outcome of using warfarin
Produces hypercoagulation then over a few days, as clotting factors are consumed and no replacements are made, patient will becomes anticoagulated
How can warfarin be used for an immediate coagulation effect
In combination with heparin
What type of drug is warfarin
Coumarin based anticoagulant
How long until warfarin loses its effect
Once stabilised will take 2-3 days to lose effect if drug is stopped
Why must warfarin be monitored regularly
Heavily bound to plasma proteins and metabolised in the liver so other medications can interfere with the warfarin action and change the degree of coagulation
What is INR
International Normalised Ratio
A ratio of healthy volunteers prothrombin time (time to convert prothrombin to thrombin) measured against the patient
What is a therapeutic INR range and how does it affect dental care
2-4
If within the range - no attention needed for dental care
If out of range - refer for medical advice
What should be given to patients on warfarin during dental treatment
Apply measures to area of surgery to help with bleeding - fibrinogen activator, suture or LA with a vasoconstrictor which will slow blood flow through the area
What drugs should be avoided in dental care if a patient is on warfarin
Avoid analgesics
Give examples of NOACs as well as how often they should be taken and what they inhibit
Rivaroxaban - once daily (aXi)
Apixaban - twice daily (aXi)
Dabigatran - twice daily (dTi)
Edoxaban - once daily (aXi)
Describe the properties of NOACs
Do not require monitoring and have predictable bioavailability so amount of drug absorbed and metabolised each day is the same and other drugs rarely interfere with their action
Short half live so their effect is rapidly lost
Give examples of beta-adrenergic blockers and what receptors do they act on
Atenolol - selective - B1 only
Propranolol - non selective - B1 and B2
Many others ending in -olol
What are the functions of beta blockers
Stops arrhythmias leading to cardiac arrest
Reduces heart muscle excitability
Prevent increase in HR which
Improve survival after MI
What are the disadvantages of beta blockers
B2 blockers will prevent the action of salbutamol in the lungs making asthma worse or difficult to treat
When beta blockers prevent an increase in HR, what can this cause
Postural hypotension
Poor brain perfusion, causing unconsciousness and collapse
Prevent unusual heart rhythms which can lead to heart attacks
What are lipid lowering drugs and give examples
HMG coA Reductase Inhibitors (-statins)
Simvastatin - a prodrug
Atorvastatin
Rosuvastatin
What is a prodrug
A biologically inactive compound which can be metabolised in the body to produce a drug
What is the function of statins
Inhibits cholesterol synthesis in the liver reducing total cholesterol and LDLs
What are the side effects of statins
Myosotis with some drug interactions - some dental antifungals - fluconazole
Must stop statins for antifungals
When are nitrates used
In emergency management of angina, chats pain or long term prevention of angina
What are the different types of nitrates and when are they used
Short acting - glyceryl trinitrate (GTN)
- emergency management of angina pectoris
Long acting - isosorbide mononitrate
- prevention of angina pectoris
How should GTN be administered and why is this
Sublingually in a spray as it is metabolised in first pass metabolism
How should isosorbide be administered
Via a dermal transcutaneous patch
What are common side effects of nitrates
Headache
Hypertension
What are the outcomes of using nitrates
Dilate veins - reducing preload to heart and cardiac workload
Dilate resistance arteries - reducing cardiac workload and oxygen consumption
Dilate collateral coronary artery supply - reducing anginal pain
What are the different types of diuretics
Thiazide diuretics (bendroflumethiazide) Loop diuretics (frusemide)
What is the function of diuretics
Increases salt and water loss, reducing plasma volume and reducing cardiac workload
What are the side effects of diuretics
Can lead to N+/K+ imbalance if not monitored carefully
Fluid loss can be excessive leading to dehydration - presents as dry mouth
What are diuretics used to treat
Hypertension
Heart failure
What are calcium channel blockers used to treat
Hypertension
Migraines
What is the side effect of calcium channel blockers
Can lead to gingival hyperplasia if oral hygiene is poor
How to calcium channel blockers work
Blocks calcium channels in smooth muscles causing vasodilation and a reduction in blood pressure
Give examples of calcium channel blockers
Nifedipine
Amlodipine
Verapamil
Give examples of ACE inhibitors
Enalapril
Ramapril
Lisinopril
How do ACE inhibitors work
Inhibit conversion of angiotensin I to angiotensin II, preventing aldosterone dependent reabsorption of salt and water
This reduces blood pressure and excess salt and water retention
Give an example of an angiotensin II blocker and how it works, and why it is used
Losartan
Acts directly to block receptors used by angiotensin II
Gives the benefits of ACE inhibitors without the side effects
What oral reactions can be found with ACE inhibitor use
Angio-oedema - tissue fluid infiltration in lips and tongue
Lichenoid reaction - area of ulceration and fibrinous deposit
What are the other side effects of ACE inhibitors
Cough
Hypotension
