Clotting Flashcards
Define stasis
Reduction in blood flow
Which anticoagulant does not need a dose adjustment in renal impairment?
Heparin. (LMWHs do need to though)
Bad side effect of heparin to be aware of?
HITS. Heparin induced thrombocytopenia syndrome - extreme drop in platelet count
Name 2 Factor Xa inhibitors
Rivaroxaban and apixaban
What monitoring do Rivaroxaban and apixaban require?
None
Common side effects of Rivaroxaban?
Bleeding, peripheral oedema, itch.
Rare = hepatotoxicity
Common side effects of apixaban?
Nausea, bleeding,
Less common= LFT changes, allergic reaction
Main difference in Rivaroxaban and apixaban dosing?
Rivaroxaban = once daily. Apixaban = twice daily
Method to follow when switching from DOAC to warfarin?
Keep taking the DOAC with warfarin until the INR is above 2 for 2 consecutive days
Dabigatran ADRs?
Bleeding, GI bleeding, indigestion, ulcers
Initiation of dabigatran?
Need to use heparin or enoxaparin for 5 days, then start dabigatran
Warfarin prevents the production of which clotting factors?
The vitamin K dependent ones.
2, 7, 9 and 10
Why are heparin and warfarin often started at same time?
Heparin onset of action is much faster, so heparin is started with warfarin until warfarin levels are high enough (takes a few days due to long half life of factor 2)
Heparin MOA?
Binds to antithrombin and inactivates factor 2a (thrombin) and Xa
Enoxaparin MOA?
Binds to antithrombin and inactivates 2a (thrombin) and Xa
Role of factor Xa?
Converts prothrombin into thrombin.
Thrombin then turns fibrinogen into fibrin
Factor Xa inhibitors?
Heparin, enoxaparin, Rivaroxaban, apixaban
Signs of excessive bleeding?
Nose bleed, bruising, pink / red urine, red or black in faeces, rash
Side effect to be aware of in with warfarin?
Skin necrosis and bleeding
Non-drug VTE prophylaxis options?
Graduated compression stockings, foot pump, etc
Aspirin in VTE prophylaxis?
Not recommended because anticoagulants are much more effective.
VTE prevention in long distance travel?
No evidence that aspirin is effective.
If at high risk, could use a DOAC or enoxaparin.
Better of with GCS or moving around
