Anticoagulation

Anticoagulation – Madeleine Turcotte

 

Agent

Dose

Renal Dose

Prophylaxis

Monitoring

Unfractionated heparin

80 U/kg bolus, then 18 U/kg/hr

No change necessary

5000 U q8 hr

PTT (automatic in order set)

Enoxaparin

(Lovenox)

1 mg/kg q 12 hr

1 mg/kg daily

40 mg daily

        or

30 mg BID

LMWH level (anti-Xa level)

Best checked 4 hr after 4th dose

 

Warfarin (Coumadin)

Start 2-5mg daily and monitor INR

Can consult Pharmacy

 

No change

necessary

N/A

PT/INR

Use Chromogenic Factor X assay if pt has APLS

Dabigatran (Pradaxa)

After 5 days of a parenteral AC,

150 mg BID

Avoid use

N/A

Can test drug level if concerned

(Any DOAC)

Rivaroxaban (Xarelto)

15 mg BID x21 d then 20 mg daily

Avoid use in CrCl<30

10mg QD

 

Apixaban (Eliquis)

10mg BID x7d, then 5mg BID

VTE: No adjustment

2.5 mg BID

A Fib:

2.5mg BID, if 2 of the following:

Cr 1.5, Age > 80

Weight < 60kg

Edoxaban (Savaysa)

After 5 days of a parenteral AC,

60 mg daily

30 mg for

CrCl 15-50

Avoid if CrCl > 95

  

Best studied option in renal dysfunction

 

NOAC/DOAC

Warfarin

Quick onset/offset, fixed dosing

Antidote/reversal agent available

Reduced incidence of hemorrhagic stroke

Measurable levels of anticoagulation effect

Fewer drug interactions, no food interaction

Strongest evidence in patients with ESRD

No need for routine monitoring

Lower risk of GI bleeding (varies)

Monthly cost $350-450 but discounts available

Monthly cost: $4

 

Additional Information

  • VA favors dabigatran among DOACs
    • Dabigatran cannot be stored in a pill box
    • PADR for apixaban citing “patient uses a pillbox and cannot use dabigatran”
  • Concomitant Malignancy: favor LMWH, can also use apixaban
  • Renal dysfunction: favor warfarin, apixaban or edoxaban
  • Hx of GI bleed: avoid dabigatran, rivaroxaban, edoxaban (may have higher risk of GI bleed)
  • Pregnancy: LMWH (other agents may cross the placenta)

 

 Indication

Agent / Duration

Other Notes

VTE

Any agent

Duration: See VTE section 

See Deciding between Agents

Atrial Fib

(non-valvular)

Apixaban or dabigatran

 

Duration: Indefinite

CHADSVASc > 2, Consider if score of 1

All DOACs: ↓ rates of ICH Apixaban & dabigatran: superior to warfarin in preventing stroke

Artificial Heart Valves

Warfarin

Target INR depends on type of valve

If the pt has concurrent Afib, may need higher INR goal

 

Duration: Mechanical, Indefinite

Surgically placed bioprosthetic, 3-6 months

DOACs contraindicated with mechanical valves!

 

Bioprosthetic valves: DOACs okay if coexisting indication

 

No AC after TAVR unless patient has other indication

ACS

PCI: Heparin or LMWH until PCI

Fibrinolytic: 2-8 days after fibrinolysis

 

If other indication for AC, assess bleeding/thrombosis risks to determine AC/Antiplatelet combination

No PCI: rivaroxaban 2.5 mg BID for 1 year, then reassess risk/benefit

 

LV Thrombus

Warfarin superior

 

Duration: At least 3 months

AC can also be considered in patients with MI who are at high risk for LV thrombus: LVEF <30% w/ antero-apical wall motion abnormalities

Portal Vein Thrombus

Any agent

DOAC preferred In cirrhosis (INR may not reflect level of anticoagulation)

Duration: 3-6 months, or indefinitely if pt has permanent thrombotic risk factors

Consider bleeding risk: large esophageal varices

Thrombophilia

Any agent (DOACs less effective in APS)

Duration: 6 months after any thrombosis

Lifelong if recurrent, life-threatening, or unprovoked

Antiphospholipid antibody syndrome: lifelong warfarin for any thrombosis that is otherwise unprovoked

 

  

 

Transitioning Between Anticoagulants with DOACs

  • LMWH to Warfarin
    • Warfarin and LMWH given simultaneously until INR is therapeutic for 24 hours
  • Warfarin to DOAC
    • Start DOAC when INR < 2.0
  • DOAC to Warfarin
    • High Risk DVT/PE – start LMWH or UFH, then start Warfarin
    • Low to Moderate Risk DVT/PE – Start warfarin while patient on DOAC, Stop DOAC on Day 3 of warfarin therapy, Check INR on day 4
  •  LMWH to DOAC
    • Stop LMWH and start DOAC when due for next dose of LMWH (within 2 hrs)
  • DOAC to LMWH
    • Stop DOAC and start LMWH when due for next DOAC dose
  • UFH to DOAC
    • Start DOAC when IV stopped (30 min prior to cessation if high risk for thrombosis)
    • DOAC to UFH
    • Start IV heparin with bolus when next DOAC dose is due

 

 

 

 Peri-Procedural Management of Anticoagulation

  • Temporary IVC filter indicated in pts with very recent acute VTE (within 3-4 weeks) if the procedure requires AC delay >12 hours
  • For those at high risk of thromboembolism:
    • Consider continuing AC for low-bleeding-risk procedures, i.e. dental procedures, cutaneous biopsy/excision, ICD placement, endovascular procedures.
    • Can bridge with LMWH or heparin drip

 

 

Stop before procedure

Restart after procedure

Warfarin

5 days prior, check INR day of

12 to 24 hours after

Dabigatran

One day prior

(2 days if CrCl 30-50 or procedure is high bleeding risk)

1 day after

(2 days if high bleeding risk)

Rivaroxaban

Apixaban

Edoxaban

Heparin

Stop infusion 4-5 hours prior

24 hours after

Enoxaparin

24 hours prior (hold evening dose if BID dosing, give half of AM dose if daily dosing)

24 hours after, (48-72 hours if high bleeding risk)

 

Strategies for Reversal of Anticoagulation

Warfarin

  • Vitamin K: onset at 12 hours but takes 24-48 hrs for full effect
    • Life Threatening Bleeding: Give IV Vitamin K 10 mg over 30 minutes
    • Intracranial bleed, bleed with hemodynamic instability, emergent procedure Non-life threatening
      • INR <5: Vitamin K not recommended
      • INR 5-10: Vitamin K 1-5 mg IV or PO
      • INR >10: Vitamin K 5mg PO or 5 mg IV
    • Prior to surgery
      • Rapid reversal INR > 5: 5mg Vit K IV (24 hours prior to procedure)
    • FFP
      • 15 ml/kg (i.e. 4 units/70 kg person) if need reversal <24 hrs, plus give Vitamin K
    • KCentra ($$$): Contains Factors II, VII, IX, and X with Protein C, Protein S, and heparin
      • Given instead of plasma when insufficient time for plasma/Vit K to work
      • Avoid giving this in HIT
      • Administer with Vitamin K

 

Dabigatran

  • Idarucizumab ($$$) will reverse if prolonged thrombin time – Consult Hematology

 

Xa drugs (Rivaroxaban, apixaban, edoxaban)

  • FEIBA (Factor VIII inhibitor bypassing activity) – can promote coagulation but is not a reversal agent; limited data to support use
  • Consult Hematology before using; andexanet alfa is not yet available here