Anti-coagulant Drugs Flashcards
Mechanism of action of warfarin
Inhibit vitamin K epoxide reductase, reduces recycling of vitamin K, reduces synthesis of prothrombin and factor VII, IX, and X
ADRs of warfarin
Bruising, Intracranial haemorrhage, GI bleeding
In pregnancy: Teratogenic, Intracranial haemorrage at birth
DDIs of warfarin
Effected by inducers and inhibitors, Displacement by drugs bound to plasma proteins, Cephalosporins reduce Vit K production in the gut
Treatment of warfarin overdose
Oral Vit K, Fresh frozen plasma, Prothrombin complex
Monitoring of warfarin
INR (2 - 4.5)
Define INR
Patients prothrombin time / expected prothrombin time
Types of heparin
Low molecular weight, Unfractionated
Mechanism of action of heparin
Activate anti-thrombin III, inhibits clotting factors
Factor affected by low molecular weight heparin
Factor X
Factors affected by unfractionated heparin
Factor X and Prothrombin
Why does low molecular weight heparin not inhibit prothrombin
Not large enough to bind both anti-thrombin III and prothrombin
ADRs of heparin
Intracranial haemorrhage, Epistaxis, GI bleeding, Osteoporosis, Autoimmune thrombocytopenia
Treatment of heparin overdose
Protamine sulphate
Monitoring of heparin
Activated partial thromboplastin time
Classes of antiplatelet drugs
Aspirin, Dipyridamole, Platelet ADP receptor blockers, Glycoprotein receptor inhibitors
Mechanism of action of Aspirin (Anti-platelet)
Inhibit COX - 1 reducing the synthesis of thromboxane
Mechanism of action of Dipridamole
Inhibit phosphodiesterase reducing break down of cAMP reducing platelet aggregation
Example of platelet ADP receptor blocker
Clopidogrel
Mechanism of action of clopidogrel
Prevent ADP from binding to platelets reducing aggregation
Example of glycoprotein receptor blockers
Abciximab
Mechanism of action of Abciximab
Prevent fibrin binding to glycoprotein receptors reducing aggregation
