Final part 3 Flashcards
Heparin MOA
binds with antithrombin to inactivate factors 10 & 2
- also 9, 11 & 12
no renal dose adjustments for
heparin & warfarin
prior to initiation of heparin therapetic doses must know:
indication
total body weight
baseline aPTT/anti-Xa & plts
- double check hgb
heparin for VTE
80u/kg then 18u/kg/hr
heparin for ACS
60u/kg then 12 u/kg/hr
heparin for VTE prophylaxis
500u SQ Q8-12H
heparin aPTT monitoring
may stop Q6H monitoring after 2 aPTTs in range & go to daily checks
- plts Q3 days
prophylactic monitoring for heparin
none
lovenox generic
enoxaparin
lovenox MOA
binds antithrombin to inactivate factors (X>II)
dosing considerations of enoxaparin
indication
renal function
total body weight
therapeutic dosing for enoxaparin
- 1mg/kg Q12H if CrCl>30
- QD if CrCl
VTE prophylaxis enoxaparin dose
- medical/surgical:40mg SQ QD
- knee replacement: 30 SQ BID
- CrCl
enoxaparin monitoring
- anti-Xa
- indicated with treatment doses in:
prego, wt 190kg - CrCl
enoxaparin anti-Xa level targets
- Q12H CrCl>30 or QD CrCl 30:1-2
- prophylaxic: 0.2-0.6
fragmin generic
dalteparin
dalteparin MOA
binds with antithrombin to inactivate factors X>II
dalteparin prophylaxis dosing
500u SQ daily
what is the agent of choice for reversal of heparinoids?
protamine sulfate
arixtra generic
fondaparinux
fondaparinux indications
- VTE prophylaxis: 2.5mg SQ QD
- VTE treatment: (100:10mg)
- CI in CrCL
MOA of argatroban
direct thrombin inhibitor
argatroban indications
- prevention/treatment of HIT
- PCI
argatroban monitoring
- aPTT
- prolongs INR
consider addition of warfarin to argatroban infusion when:
confirmed HIT PLUS plts >150
overlap warfarin & argatroban for
at least 5 days before dc argatroban
angiomax generic
bivalirudin
bivalirudin MOA
direct thrombin inhibitor
bivalirudin dosing
- PCI: 0.75mg/kg x1 then 1.75mg/kg/hr
- HIT:0.15-0.2mg/kg/hr
bivalirudin monitoring
- HIT: aPTT levels
- PCI: once time ACT
peri-operative for heparin
hold 4-6 hours before surgery & weight 48-72 hours after for high risk bleeders (24 for non-high risk)
peri-operative for LMWH
- 24 hours before & 24 hours after
warfarin MOA
- inhibits vitamin K epoxide reductase (VKOR) complex to reduce vitamin K available for the synthesis of SNOT, & Protein C & S
warfarin initial dose
5mg PO QD (5-10)
- may use 10mg x 2 day loading dose if healthy
sensitivity factors for warfarin
- use 2.5mg QD
- age over 75
- liver or renal disease
- HF
- high bleeding risk
- drug interaction
- acute etOH intake
- smoking cessation
- poor nutritional status
- infection
- malignancy
cyp2c9 & Vkorc1 genotyping
- currently not recomended
agents that increase warfarin efficacy & bleeding
amiodarone fluconazole metronidazole NSAIDs sulfonamides "G" herbals other anticoags
agents that decrease warfarin efficacy
rifampin
st johns wort
carbamazepine
INR measures factors
II, VII, & X
warfarin titration
INR:
- less than1.5: incr wk 10-20%
- 1.5-1.9:incr wk 5-15%
- 2-3 continue
- 3.1-3.5: decr wk 5-15
- 3.6-4.4: dec 10-20% & hold 2 doses
- more than 4.5: follow flow chart
warfarin INR follow up times
- initiation (outpt): 5-7 days
- out of range (less than 4.5) or 1 INR in range: 1-2 wks
- 2 or more in range: 4 wks
- severe bleeding: PRN
- INR more than 10: 1-2 days
- INR 4.5-10: 2-3 days
warfarin bridging therapy is most appropriate in:
VTE, Afib & valve replacement
- initiate warfarin & IV anticoag on day 1
- for at least 5 days until 2 INRs are above 2 24 hours apart
pradaxa generic
dabigatran
- direct thrombin inhibitor
pradaxa dosing
- 150mg PO BID
- must complete 5-10 days IV
- DVT or nonvalv AF
xarelto generic
rivaroxaban
- factor Xa inhibitor
xarelto dosing
- acute DVT: 15mg PO BID x21 then 20mg QD
- nonvalv: 20mg QD
- prophylaxis: 10mg QD
eliquis generic
apixaban
- factor Xa inhibitor
eliquis dosing
- DVT: 10mg PO ID x7 days then 5mg BID
- nonvalv: 5mg BID
- prophylaxis: 2.5mg BID
savaysa generic
endoxaban
- factor Xa inhibitor
savaysa dosing
- dvt: 60mg QD
- must complete 5-10 days IV
- nonvalv: 60mg qd
- do not use in crcl above 95 or less than 15
