Anticoag drugs Flashcards
What is the MOA of ADP receptor antagonists?
- Irreversible ADP receptor antagonists that prevent activation of the ADP receptor
- Bleeding, n, d, rash and severe leukopenia
- TTP in Ticlopindine (has more AE’s)
What is Ticlopidine?
ADP receptor antagonist
What is Clopidogrel?
adp receptor antagonist
- uses CYP2c19
What is Prasugrel?
adp receptor antagonist
What are the gpIIB/IIIa receptor inhibitor drugs?
T- Tirofiban
E- Eptifibatide
A- Abciximab
- can lead to bleeding and thrombocytopenia
What is Tirofiban?
GPIIb/IIIa receptor inhibitors
- non-peptide competitive inhibitor
What is Eptifibatide?
GPIIb/IIIa receptor inhibitors
- fibrinogen analogue
What is Abciximab?
GPIIb/IIIa receptor inhibitors
-humanized MAB against receptor
What is Dipyridamole and what is its MOA?
Increased cAMP in 2 ways:
- phosphodiesterase 3 inhibitor (prevents breakdown)
- Adenosine reuptake inhibitor (longer activation)
- Increase cAMP inhibits platelet activation
- use with aspirin and warfarin
What are the 2 divisions of the thrombin inhibitors?
Direct and indirect
What are the indirect thrombin inhibitors?
Unfractionated heparin (HMW)
LMW heparin
Fondaparinux (synthetic)
What are the direct thrombin inhibitors?
B- Bivalifudine
A- Argatroban
D- Dabigatran
What is the the MOA indirect thrombin Inhibitors?
Bind to antithrombin to have their efficacy
- this effects and decreases both thrombin and Xa
Where is heparin from and how does it act?
Pigs
- it is size dependent and is variable response
- 1 HW and 4 LW 1/2 time
- 30% and 90% bioavailability
what is the advantage of monitoring in LMW vs High?
There is no need for monitoring of most patients
- HMW need aPTT and PTT
whats the difference between aPTT and PTT?
aPTT is activated by addition of Factor XII as well as the phospholipids that are added to the PTT
- causes it the clot faster
- usual time is 2-4 minutes
- measures intrinsic
What would it mean if aPTT is elevated and PT(INR) is normal?
something wrong with the intrinsic pathway
- could be 1,2,5,8,10,11,12 factors
- used to monitor heparin effectiveness
What are some facts about INR (PT)?
clots in 12-14 seconds if you add thromboplastin
- if this is prolonged with normal aPTT then you have a problem with the extrinsic pathway
- measures 1,2,5,7, and 10
BEST For WARFARIN monitoring and 7 status
Heparin induced thrombocytopenia happens more in what sex?
women- crazy haha
- IgG abs against complexes with platelet factor 4
How doe oral anticoagulants work and what are they?
Warfarin
- blocks synthesis of Vitamin dependent clotting factors
- blocks VCOR1C which is epoxide reductase and reduces Vitamin K to its useful form
- War has vitamin K for antidote
What factors rely on Vitamin K reduced form?
2,7,9,10, C and S
Inhibits K-dependent Gamma carboxylation which is what directly uses the reduced form of vit K (Pyhtonadione)
What are some Direct Xa inhibitors
Rivarxaban
- more rapid and shorter 1/2 than warfarin and less drug/drug interactions
- No antidote if you OD however***
What would you order to monitor Warfarin?
PT (INR)
- measures the extrinsic pathway
What liver enzyme does Warfarin interact with?
CYP29C
- S is more acitive enantiomer
