Anticoagulation Flashcards
overall steps of bridging therapy
stop warfarin 5 days prior to surgery
give LMWH or UFH until surgery (last dose 24 hours prior)
resume warfarin 24 hours after
overlap warfarin and LMWH for at least 5 days and INR therapeutic
what are the drugs for post-op prophylaxis
dabigatran (hip only)
rivaroxaban
apixaban
what are the drugs for non-valve Afib
dabigatran
rivaroxaban
apixaban
edoxaban
what are the drugs for DVT/PE treatment
dabigatran
rivaroxaban
apixaban
edoxaban
what are the drugs for secondary prevention of DVT/PE
rivaroxaban
apixaban
what are the drugs for VTE prophylaxis
rivaroxaban
Dabigatran MOA, reversal agent, and considerations
direct thrombin inhibitor
reversal = idarucizumab
avoid w/ renal impairment
Rivaroxaban MOA, reversal agent, and considerations
Direct Xa inhibitor
reversal = adexanet
decrease dose with renal impairment
Apixaban MOA, reversal agent, and considerations
Direct Xa inhibitor
reversal = adexanet
decrease dose with renal impairment
Edoxaban MOA, reversal agent, and considerations
Direct Xa inhibitor
no reversal agent
cannot use if CrCl > 95 (afib only)
increased risk of hematoma
what is the initial warfarin dosing
5mg PO daily
overlap with UFH/LMWH/Xa for at least 5 days and until INR is therapeutic
what is the main INR goal
2.0-3.0
what is the INR goal for aortic valve replacement and mechanical heart valve (mitral/high risk)
2.5-3.5
INR less than 2.o
increase dose by 5-15%
INR 3.1-3.5
decrease dose by 5-15%
INR 3.5-4.O
hold 1 dose
decrease dose by 10-15%
INR > 4
hold 0-2 doses
decrease dose by 10-15%
what are the questions to ask a warfarin patient
Drugs?
Diseases?
Doses missed?
Diet?
Drinking?
Signs of bleeding/bruising?
UHF dosing, administration, reversal agent, and AEs
weight based dosing
IV bolus or infusion (rapid)
reversal = protamine sulfate
AE: thrombocytopenia
LMWH dosing, admin, reversal agent
fixed or weight based dosing
longer half life so can be SQ
reversal = protamine sulfate
HAT definition
mild decrease of platelets (<100,000)
occurs 48-72 hours
do not need to d/c heparin
HIT definition
Platelet drops >50% baseline or > 100,000)
stop all heparin/warfarin and give alternative anticoag therapy
evaluate for thrombosis
INR 4.5-10 + no evidence of bleeding
avoid VIT k
INR > 10 + no evidence of bleeding
PO vitamin K
major bleeding on warfarin
Prothrombin complex concentrate or fresh frozen plasma
pcc is preferred and is faster
CHADSVASc conditions and points
congestive HF = 1
hypertension = 1
age (75+) = 2
diabetes = 1
Stroke/TIA = 2
vascular disease = 1
age (65-74) = 1
female = 1
what are the 3 phases of platelet activation
adhesion: intact cells secrete PGI2 to inhibit thrombogenesis
secretion: degranulation (ADP, TXA2, 5-HT vasoconstrictors) factors are secreted to recruit other platelets
aggregation: factor activation induced confirmation for binding to fibrinogen to form clot
MOA of ADP inhibitors
P2Y12 is coupled to Gi and inhibits adenylyl cyclase. these drugs block P2Y12 and block aggregation
ADP inhibitor drugs
clopidogrel
prasugrel
ticagrelor
cangrelor
MOA of GP iib/iiia receptor inhibitors
stops fibrinogen cross-linking at GPiib/iiia site
GP iib/iiia inhibitor drugs
eptifibatide
tirofiban
abciximab
MOA of PDE-3 inhibitors
platelet aggregation inhibitor
inhibition of adenosine uptake
PDE-3 inhibitor drugs
dipyridamole
cilostazol
Heparin (UFH) MOA
binds to free antithrombin
changes confirmation
increases interaction of AT with target factors
Heparin side effects
iatrogenic hemorrhage
HIT
osteoporosis
LMWH drugs
enoxaparin
daltaparin
LMWH MOA
binds to antithrombin
smaller so only binds to Factor Xa
LMWH side effects
HIT
osteoporosis
CI w/ renal failure
warfarin MOA
inhibits synthesis of factors II, VII, IX, and X
direct thrombin inhibitor drugs
bind to active site of thrombin
inhibit soluble and fibrin-bound thrombin
direct thrombin drugs
bivalirudin
argatroban
dabigatran
Factor Xa inhibitors drugs
Fondaparinux
Edoxaban
Rivaroxaban
Apixaban
