CVS 6 Flashcards
What are the roles of thrombin?
- Cleaves fibrinogen to make fibrin
- Casues activation of platelet aggregation
what are the two types of haemostasis and which one is more stabilising?
- Primary haemostasis - occurs straight after vascular damage (but not stable)
- Secondary haemostasis - which activates the clotting cascade (forms more stable plaques/platelets)
what is thrombosis?
- The formation of a blood clot within the blood vessles (also known as thrombus)
what are the three causes of thrombosis?
- Endothelial injury (major cause in heart)
- Abnormal blood flow (replace laminar flow with turbulent flow)
- Hyercoaguability (family/ heparin)
Arterial and venous thrombosis are not different. true or false?
false
Arterial and venous thrombosis are treated differently. TRUE OR FALSE?
TRUE
Describe arterial thrombosis?
- More platelet rich
- Cuases strokes and heart attacks
- Due cholesterol levels, obesity, smoking
- Treated by reducing risk factors e.g stoke smoking and antiplatelet drugs
Describe venous thrombosis?
- Fibrin rich
- Cuases DVT and pulmonary embolism
- Due to slow blood flow and genetic factors
- treated with anti-coagulants
Anti-platelet drugs are not effective in venous thrombosis. true or false?
true
Atrial fibrilation increases risk of arterial thromboembolism. TRUE OR FALSE?
TRUE
what are fibrinolytic agents used for?
- Acute MI
- pulmonary embolism
GP-2B3A is used to activate platelet aggregation. TRUE OR FLASE?
TRUE
Phospholipid is cleared by phospholipase A2. TRUE OR FALSE?
TRUE
Blocking protsangladin blocks thromboxane production. true or false?
true
What is Apsirin indicated for?
- prevention of thromboebolism in atheroscletoic disease, angina, MI and stroke
How does aspirin work as an anti-platelt drug?
- Inhibits COX-1 acetylation
- Inhibits prostanglagin synthesis in platetelets
Aspirin has minimal ADRs with low doses and a half life of 15 min. true or fase?
true
What are some of the serious ADRs with apsirin?
- It causes haemorrhage - execssive bleding
- Avoid in patients with peptic ulcer disease
- Avoid in hypertension - leads to more bleeding
- Aspirin can also have other intrecations with anti-coagulants
other NSAIDS can interact with aspirin because asprin binds irrevesibly and NSAIDS can compete with asprin reducing aspirins ability to inhibit COX1 acetylation. TRUE OR FLASE?
TRUE
How do PDE inhibitors work as anti-platelet drugs?
- They promote PKA which inhibits the activation of platelets
Provide an example of a PDE inhibitor drug?
- Dipyridamole
what are the inidcations for PDE inhibiotrs as antiplatlet drug?
- It is a weak anti-plateet drug - not commnly used
- Ischeamic stroke
- Prevention of embolism in patients with prosthetic heart valves
what are soem ADRs of PDE inhibitors?
- can cause bleeding avoid in patients with GI bleeding
- interact with anti-coagulants leading to haemorrhage
In platelets cAMP inhibits aggregation. TRUE OR FALSE?
TRUE
Provide a drug name for ADP antagonist?
- Clopidogrel 2nd generation drug
what is the mechanism of action of ADP anatgonits?
- ADP receptor antangonists
what are ADP antangonists indicated for?
- Coronary syndrome
- prevention of athoscelrosis in angina
what are some ADRS for ADP antagonist?
- Can cause bleeding
Clopidogrel is a pro-drug and its active metabolite binds irreversibly to the receptor. TRUE OR FALSE?
TRUE
why are GP2B3A antagonists very effective?
- Because they inhibit the ned point of platlet aggreagation
GP2B3A they have long half lives (24hrs), the only way to reverse this is by platelet infusion. TRUE OR FLASE?
- TRUE
GP2B3A are indicated fo unstable angina. TRUE OR FALSE?
true
Epifibatide is a peptide antagonist. true or false?
true
what is heparin?
- It is an anticoagulant
- It is a sulphated polysaccharide obtained from lung bovine and porcine instestine
How does heaprin work?
- Inhibits clotting factors which leads to irreversible binding of anti-thrombin 3
Heparin is indicated for rapid anti-coagulant effects and for treatmetn of thromboebolism. TRUE OR FALSE?
TRUE
Heparin has low oral F, it is givena s an S.C. injection. TRUE OR FALSE?
TRUE
what is warfarin?
- An anti-coagulant
what is the meachnism of action of warfarin?
- Inhibits vitamin K and clotting factor synthesis
warfarin has a delayed effect, so for fatser relief use other anti-coagulants. TRUE OR FALSE?M
TRUE
what are some ADRs for warfarin?
- Haemorrhage
- low therapeutic window
what are the contraindications for warfarin?
- it is teratogenic
- Can cause peptic ulcers
warfarin is 99% plasma protein bound, so other drugs can displace. TRUE OR FLASE?
true
Thrombin inhibitors are indicated for venous thromboebolism. true or false?
true
Dabigatran etexitile is a pro-drug activated by plasma/ liver esterase. true or flase?
True
What are the indications for factor (X)10a inhibitors?
- They are indicated for venous thromboebolism
what is fribrinolysis?
- The breakdown of fibrin from pre-existing thrombus
Give an example drug of fibrinolitic agent?
- Altapase e.g short half life 30 min
what is skeptokinase?
- Forms complex with plasminogen and allows activation of other plasminogen complex
when is firbinolytic agents used?
- when in urget need to break down the firbirn clot e.g MI, stroke
List all the drugs for anti-platelet and anti- coagulant drugs for treatment of thrombosis?
Antiplatelet drugs:
- Aspirin
- PDE inhibitors
- ADP antagonists
- GP2B3A antagonists
Anti-coagulants:
- Heparin
- Warfarin
other
- Fribinolytic agents
- Factor Xa inhibitors
- Thrombin inhibotrs
