Anticoagulants Flashcards
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.
Which anticoagulant do you use for Prosthetic Mitral Valve patients? INR goal? Duration of treatment?
Warfarin.
INR goal: 2.5-3.5
Duration: indefinite.
Warfarin monitoring
INR check daily initially things are stable and they are out of your hands.
LMWH medicine prophylaxis dose
40mg QD
LMWH hemodialysis prophylaxis dose
20mg QD
LMWH trauma prophylaxis dose
30mg q12**
