Antiplatelet Drugs Flashcards
What are the release products of the light (alpha) granules?
Platelet factor 4
Beta-thromboglobulin
Platelet-derived growth factor (PDGF)
What are the release products of the dense (beta) granules?
Ca+2
Serotonin (5-Hydroxytryptamine)
ATP/ADP
Is primary aggregation reversible? Is secondary?
Primary aggregation is reversible but secondary is NOT.
What are the functions of the anti platelet drugs?
An antiplatelet drug is a member of a class of pharmaceuticals that decreases platelet adhesion, activation and aggregation thereby inhibit thrombus formation.
What is the difference in effectiveness of the anti-platelet drugs in the arterial circulation VS drugs like heparin and warfarin?
These drugs are effective in the arterial circulation, where anticoagulants such as heparin and oral anticoagulants have relatively little effect.
What is the general usage of anti-platelet drugs?
They are widely used in primary and secondary prevention of thrombotic cerebrovascular or cardiovascular disease
Which of the ADP receptor inhibitors are prodrugs?
Ticlopidine
Clopidogrel
Prasugrel
What is the difference between these two ADP receptor inhibitors: Ticagrelor and Cangrelor?
Cangrelor is available via IV only whereas Ticagrelor is oral
What is the most potent class of anti platelet drugs?
GPIIb/IIIa Inhibitors
What are the COX inhibitors?
Aspirin
Celecoxib (COX2 only)
Ibuprofen
Naproxen
What are the ADP receptor inhibitors?
Ticlopidine Clopidogrel Prasugrel Ticagrelor Cangrelor
What are the GP IIb/IIIa inhibitors?
Abciximab
Tirofiban
Eptfibatide
What is a PAR-1 antagonist?
Vorapaxar
What is the difference between the ADP receptor inhibitors Clopidogrel and Prasugrel?
Prasugrel has less population variation in response to treatment so it is more likely to be effective in patients.
How is anti platelet therapy generally administered?
Dual Antiplatelet Therapy as combination therapy often with aspirin. Sometimes even Triple Therapy is used.
What are some of the clinical applications of anti-platelet drugs?
- Cerebrovascular disease:
a. Transient ischemic attack (TIA)
b. Complete stroke - Coronary artery disease:
a. Acute myocardial infarction - Saphenous vein coronary artery bypass grafts
- Venous Thrombosis
- Claudication
- Thrombotic thrombocytopenic purpura
- Prevention of thrombus formation on artificial surfaces
What are some drugs that possibly have interaction with anti-platelet drugs?
- Thrombolytic agents (urokinase, streptokinase and tissue plasminogen activator)
- Heparin/LMW heparin/oral anticoagulants
- Warfarin
- Antithrombin agents (hirudin, bivalirudin and argatroban)
What are the two major pathways of arachidonic acid metabolism?
- Cyclooxygenase pathway
2. Lipoxygenase pathway
What is the main drug that acts on the Cyclooxygenase Pathway?
Aspirin
What are the main products of the Cyclooxygenase Pathway in platelets?
TXA2
What is the main product of the Lipoxygenase Pathway in leukocytes?
Leukotrienes
What are the leukotriene antagonists and what are they used for?
- Montelukast is used for the treatment of asthma and seasonal allergies
- Zarirlukast is used in the treatment of asthma
Aspirin MOA and Route of Administration
COX inhibitor
Oral
Aspirin Indications
ACS, stroke, arterial thrombosis
