Anticoagulants Flashcards
What is the function of heparin?
Potentiates anti-thrombin
What are 2 forms of heparin?
Unfractionated
Low molecular weight (LMWH)
How is unfractionated heparin monitored?
APTT
How is LMWH monitored?
Anti-Xa assay
Usually no monitoring required
What are the complications of heparin?
Bleeding
Heparin induced thrombocytopenia
Osteoporosis
How is heparin reversed?
Stop heparin
What is given in severe bleeding with heparin?
protamine sulphate
Reverses antithrombin effect
What anticoagulants are Coumarin/Inhibit vitamin K?
Warfarin
Phenidione
Acenocoumarin
Phenprocoumon
What is vitamin K?
fat soluble vitamin
Where is vitamin K absorbed?
Upper intestine
What is required for vitamin K absorption?
Bile salts
What is vitamin K needed for?
Carboxylation of clotting factors II,VII,IX and X
Protein C and protein S
Where are clotting factors 2,7,9 and 10 synthesized?
Liver
What is the function of warfarin/
Antagonises vitamin K so clotting factors are non functional
What is warfarin’s therapeutic window like?
narrow
What are the 3 steps to warfarin therapy?
Initiation
Stabilisation
Maintenance
What time of day should warfarin be taken?
6pm
Same time everyday
how is warfarin measured?
INR
How is INR calculated?
Patient’s PT/Normal PT
What is a major side effect of warfarin?
haemorrhage
What might increase the bleeding risk of warfarin?
Intensity of treatment
Other clinical disorders
Other medications/DRUG interactions
Quality of management
What are complications of bleeding?
Skin bruising Epistaxis Haematuria GI bleeding Intracerebral Drop in Hb => anaemia
How is warfarin reversed/
Omit doses
Oral Vitamin K (6 hours)
Clotting factors (immediate)
Lab assessment of response
What is a thrombin inhibitor?
Dabigatran
