Anticoagulants Flashcards
Therapeutic indications
Prophylactic indications
VTE - DVT/PE
DVT/PE in high risk patients
Stroke
Heparin (LMWH):
Examples - D, E
What compound does it potentiate the effects of?
How many times a day does it have to be given?
Route?
Is monitoring required?
When is it usually used?
Dalteparin
Enoxaparin
Anti-Thrombin which inhibits thrombin
Twice daily
SC
No monitoring
In early management of VTE
Unfractionated heparin (UFH):
Route? - 2
What monitoring is needed?
SE for both:
- What is the main SE?
- What other haematological pathology may heparin induce?
- What bone disease does it cause?
IV/SC
Rapid onset
aPTT for dose adjustment as it has a short half-life
===
Bleeding
Heparin-induced thrombocytopenia
Heparin causes increased bone resorption by stimulating osteoclasts and suppressing osteoblast function, leading to decreased bone mass.
Warfarin:
Route?
What is it usually used for?
How is it monitored?
What clotting factors does it antagonise?
What can be used to reverse it?
Why is LMWH needed as a bridge between starting warfarin and it’s effectiveness?
PO OD
Long term anticoagulation
INR
10, 9, 7 and 2 - 1972!!
Vit K
When a Vit K antagonist is initiated, the natural anticoagulants (Protein S&C) drop faster than the clotting factors as they have a shorter half life.
So warfarin initially makes you prothrombotic.
DOACs:
Examples - R, A
What factor do they inhibit?
Why is it a good alternative to warfarin for long term anticoagulation?
DOAC’s - Direct Thrombin Inhibitors:
Give an example - D
Rivaroxaban
Apixaban
Factor 10a
No
Only needs quarterly assessment and annual blood tests unlike warfarin which needs INR
Dabigatran
Beginning therapeutic anticoagulation:
CHECK GUIDELINES
What is used to when beginning warfarin to cover gap in the effectiveness?
LMWH and UFH
Are the following anticoagulants, antiplatelets or fibrinolytic drugs?
Heparin
Rivaroxaban
Aspirin
Warfarin
Dabigatran
Apixaban
Urokinase
LMWH
Streptokinase
Ticlopidine
Alteplase
Clopidogrel
ACoags
ACoags
APlatelets
ACoags
ACoags
ACoags
Fibrnolytics
ACoags
Fibrnolytics
APlatelets
Fibrnolytics
APlatelets
What is the ChadVasc score used in and what does it calculate the risk of?
What about the HAS-BLED score?
Used in AF when
Calculates the risk of a bleed
Choosing your anticoagulant:
What is best if they have impaired renal function?
What 2 types are good if they have a low or high BMI?
Warfarin
Warfarin and LMWH
Stopping for surgery:
How many days before surgery would you stop Warfarin?
What does bridging mean?
What patients would they be done in? - 3
Low risk procedure and normal renal function - how many hours before surgery would DOACs need to be stopped?
5 days before
‘Bridging” is a term that refers to the use of short-acting anticoagulants (heparin or LMWH) for a period of time during interruption of warfarin therapy when the INR is not within a therapeutic range.
Consider bridging in patients who:
have a high risk of VTE
have AF with a CHADs ≥ 4 or had a recent CVA/TIA
Have a metallic mitral valve (not aortic unless other risk factors)
24 hrs
Emergency reversal:
What drug can be given which is a procoagulant?
Vit K is used for warfarin. How many hrs does it take?
What else can be given in the end?
What drug is vein for Heparin even though it is not the most effective?
Dabigatran reversal:
- What can be given within 2 hrs to inhibit absorption in the gut?
- Praxabind is used. What type of drug is it?
Tranexamic acid
4-6 hrs
Beriplex + Vit K
Protamine
Activated charcoal - same used for DOAC’s as no real reversal
A monoclonal antibody
Cautions:
What should patients apps for the first 6-8 weeks of anticoagulant therapy?
They should avoid contact or high impact sports because of the risk of bleeding
