Haematology Flashcards
Aspirin: mechanism of action
aka Acetylsalicyclic acid
Anti-platelet drug
Irreversibly activates COX enzyme > reduces TXA2 (reducing platelet aggregation/thrombus formation) and PGI2 (decreases nociceptive sensitisation and inflammation)
Aspirin: indications
Secondary prevention of thrombotic events
Pain relief
Clopidogrel: mechanism of action
Anti-platelet drug Irreversibly blocks ADP-receptor on platelet cells = inhibits GPIIb/IIIa complex for platelet aggregation, so reduces thrombus formation
Clopidogrel: indications
Secondary prevention of thrombotic events
Clopidogrel: adverse effects
Bleeding
Abdominal pain/diarrhoea
Tenecteplase / Alteplase: mechanism of action
Recombinant Tissue Plasminogen Activator (rtPA)
Catalyses conversion of plasminogen to plasmin to promote fibrin clot lysis
Tenecteplase / Alteplase: indications
Within hours of acute ischaemic stroke / MI / massive PE
Heparin: mechanism of action
Enhances activity of antithrombin III > inhibits thrombin > achieves anticoagulant effect
Heparin: indications
Thromboembolic diseases
Renal dialysis
Acute Coronary Syndrome
Heparin: adverse effects
Bleeding (3.5%)
Heparin-induced thrombocytopenia
Osteoporosis
Warfarin: mechanism of action
Vitamin K Antagonist
Inhibits vitamin K reductase which prevents vitamin K recycling when coagulation factors are broken down - prevents thrombus formation
Warfarin: indications
Venous thromboembolism
Thromboprophylaxis in AF/metallic heart valves/cardiomyopathy
Dabigatran: mechanism of action
Direct thrombin inhibitor
Prevents conversion of fibrinogen to fibrin - so directly prevents thrombus formation
Dabigatran: indications
Prophylaxis of venous thromboembolism
Rivaroxaban: mechanism of action
Factor Xa antagonist
Inhibits prothrombin to thrombin conversion, so inhibits fibrin clots
