Unit 9: Circulation and Coagulation Flashcards
Name 5 thromboembolic diseases
DVT PE Stroke Acute Coronary Syndrome (MI) Arterial Occlusion (PAD)
What is the difference between ANTI-PLATELET and ANTI-COAGULANT?
Anti-Platelet: prevents platelet aggregation
Anti-Coagulant: prevents formation of fibrin by inactivating coagulation factors
What are Protein C?
naturally occurring anticoagulant
What is Protein S?
naturally occurring cofactor required to activate Protein C
What happens if a person is deficient in Protein C or Protein S?
they are more likely to make clots
What does Nitric Oxide have to do with clotting?
it is a vasodilator released by the endothelium that inhibits PLT aggregation
What labs monitor the effect of heparin?
aPTT
What labs monitor the effect of warfarin?
PT/INR
What do anticoagulants do?
stabilize clots (prevent growth) prevent clots
DO NOT dissolve clots
Name 4 classes of anticoagulants
heparins
warfarin
Factor Xa Inhibitors
Direct Thrombin Inhibitors
Name the heparins
unfractionated heparin
LMWH
Name the antidotes for unfractionated heparin
protamine sulfate or FFP
Major risk/adverse effect of heparin
HIT
Adverse effects of unfractionated heparin
bleeding
hyperkalemia
osteoporosis if used > 6 months
antigenic (lots of allergic reactions, including HIT)
Name 2 LMWH drugs
enoxaparin (Lovenox)
dalteparin (Fragmin)
What makes enoxaparin preferred over unfractionated heparin?
longer half life –>
less frequent dosing
more predictable anticoagulant effect
What anticoagulant is preferred in pregnancy
enoxaparin preferred over heparin
Why is enoxaparin not recommended for renal impairment?
enoxaparin is renally excreted
if GFR < 30, takes longer to reverse and bleeding risk is increased
Adverse effects of enoxaparin
bleeding
hyperkalemia
HIT
Antidote for enoxaparin
protamine sulfate
BUT reversal is not complete as heparin works in factor III and enoxaparin works mostly on Xa
What kind of drug is fondaparinux (Arixtra)?
indirect inhibitor of factor Xa (anticoagulant)
Why is fondaparinux preferable over enoxaparin?
does not inhibit thrombin –>
less likely to cause thrombocytopenia
good for patients with HIT or prior HIT
Major issue with fondaparinux
no antidote
What is HIT?
heparin induced thrombocytopenia
allergic reaction and adverse event
Name the types of thrombocytopenia
Type 1: direct effect on PLT -->
cause clumping
PLT > 100K
Type 2: LIFE THREATENING
immune-mediated
heparin-PLT factor IV antibody complex
hyper coagulable stateName 2 direct thrombin inhibitors
argatroban
lepirudin
How does warfarin work?
inhibits vitamin K epoxide reductase and therefore interferes with production of vitamin-K dependent clotting and anticlotting factors (II, VII, IX, X)
Antidotes for warfarin
vitamin K
FFP
How is the thrombosis in early warfarin therapy managed?
ALWAYS BRIDGE warfarin with heparin/LMWH
Interactions with warfarin
A TON…lots of drugs increase the INR, others decrease the INR
PPIs
What are DOACs?
direct oral anticoagulants
Name 4 DOACs
rivoroxaban (Xarelto)
apixaban (Eliquis)
edoxaban (Savaysa)
betrixaban (Bevyxxa)
What is nonvalvular A-Fib, and what is the risk?
patients with no prior valve replacement who have A-Fib, and it can cause stroke
Why is it important to know half life with DOACs?
help with knowing washout time prior to invasive procedures
Name 2 anticoagulants that are not DOACs but get confused with them
fondaparinux
dabagatran (Pradaxa)
What is dabagatran (Pradaxa)?
direct thrombin inhibitor
Name 3 direct thrombin inhibitors
dabagatran (Pradaxa) [PO]
bivalrudin (Angiomax) [IV]
argatroban (Acova) [IV]
Name the reversal agent for dabigatran (Pradaxa)
Idarucizumab (Praxbind)
Name 4 categories of anti platelet agents
NSAIDs/ASA
Glycoprotein IIb/IIIa Inhibitors
ADP Receptor Antagonists
Phosphodiesterase Inhibitors
Major adverse effects of the NSAIDs/ASA
GI upset
nephrotoxicity
Name 6 NSAIDs/ASA
ASA ibuprofen naproxen diclofenac meloxicam ketorolac
Name 3 glycoprotein IIb/IIIa inhibitors, and how they are given
IV only
abciximab (Reopro)
eptifibatide (Integrilin)
tirofiban (Aggrastat)
Name 3 ADP Receptor Antagonists
clopidigrel (Plavix)
prasugrel (Effient)
ticagrelor (Brilinta)
Genetic issue to be aware of regarding clopidigrel
decreased efficacy in poor metabolizers of CYP450 enzymes
Interactions to be aware of with ADP Receptor Antagonists like clopidogrel
increased risk of GIB with NSAIDs
What does the FDA recommend for patients on clopidogrel
genetic testing for CYP2C19 phenotype as some types are poor metabolizers and experience decreased effectiveness
For whom is prasugrel (Effient) contraindicated?
if prior TIA or stroke
What is important to remember about ASA and ticagrelor?
For patients on a maintenance dose of ASA > 100mg, effectiveness of Brilinta is decrased
Name some adverse effects of ticagrelor (Brilinta)
hyperuricemia
14% will feel SOB
2-6% will experience a brief ventricular pause on EKG
Name some drugs used in bleeding disorders
tranexamic acid
DDAVP
vitamin K
4FPCC (Kcentra)
For what bleeding disorders are desmopressin (DDAVP) used?
mild hemophilia A
von Willebrand’s disease
For what bleeding disorder is vitamin K used?
reversing supratherapeutic INR liver disease (as clotting factors are made in the liver) nutritional deficiency of vitamin K
How is vitamin K given? Via which route is it best absorbed?
SQ, PO, IV
absorbed more consistently: PO
For what is 4FPCC (Kcentra) used?
rapid reversal of warfarin in bleeding patients
for bleeding in patients not on vitamin K antagonists (off label)
Why can Kcentra cause a hypersensitivity reaction?
it is human blood product containing clotting factors II VII XI X Protein S Protein C
