Anticoagulants Flashcards
(29 cards)
Heparin is administered by:
Continuous infusion
- To large for oral absorption
UFH typical prophylaxis dose:
5,000 units q8-12hrs SQ
- SQ so that you don’t have to put a line in.
When do we give UFH bolus doses?
When immediate and full anticoagulation is required.
- NEVER if stroke
Follow up with continuous infusion.
What do we use to monitor UFH
aPTT most places
Range: 76-120
Antifactor Xa some places
Range: 0.3-0.7 UmmL
UFH typical continuous infusion dose:
15-18 U/kg IV
UFH typical bolus dose:
80-100 U/kg IV
When do we usually check aPTT levels with UFH?
6 hours
Check anti-Xa levels with UFH if:
aPTT falsely elevated due to:
Antiphospholipid Antibiodies (APLA)
Advanced liver disease
SLE
When to check chromogenic factor Xa with Warfarin
INR falsely elevated due to:
Anticardiolipins
Advanced liver disease
SLE
Reasons for newer anticoagulant drugs:
Oral formulation
HIT
LMWH typical treatment dose
1 mg/kg q12
Enoxaparin in CrCl < 30mL/min
Reduce dose to 1mg/kg/DAY
Check levels 4 hours after the 2nd and 3rd doses.
When to check Anti-Xa levels with LMWHs:
CKD
Pregnancy
Obesity
Fondaparinux
Pretty much only use if they got HIT.
Very long t1/2
DC if CrCl < 30
Time to full anticoagulation with Warfarin
5-15 days
Argatroban
For patients with intermediate to high risk of HIT.
Goal aPTT: 40-70
Draw aPTT after 2hrs
DOAC Targets
Dabigatran: IIa
Rivaroxaban: Xa
Apixaban: Xa
DOAC t1/2
Dabigatran >
Rivaroxaban >
Apixaban
Therapeutic Anti-Xa levels for enoxaparin
0.7-1.2
Warfarin starting dose
2.5<5mg initially
NOT 10mg like CHEST says
Heparin to warfarin
After 2 stable INRs
Monitoring warfarin in patients with APLA and lupus
Chromogenic Factor Xa
- Goal level: 40-20%
- The lower the number, the more anticoagulated they are
- Need to do this every few months to ensure INR correlates correctly.
MUST CALCULATE CrCl ON TEST!
NEEDED FOR ENOXAPARIN DOSING
DOAC of choice for patients with renal dysfunction
Apixaban
- Dual metabolism.
