multi class comparison

Anticoagulant Comparison: Heparin vs Warfarin vs DOACs — Onset, Monitoring, Reversal

A patient on anticoagulation starts bleeding, and the NCLEX asks what you give. Protamine, vitamin K, or idarucizumab — choosing wrong delays reversal and worsens hemorrhage. Mixing up which lab monitors which drug means you'll misinterpret results and miss a critical therapeutic failure.

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Comparison

Side-by-side3 compared
Comparevs
Dimension
Heparin (UFH/LMWH)
Warfarin
DOACs
Class & mechanism
  • Potentiates antithrombin then inhibits IIa & Xa
  • Vitamin K antagonist then ↓ II, VII, IX, X
  • Direct Xa (–xabans) or IIa (dabigatran)
Indications
  • Acute venous thromboembolism, ACS, periop bridging
  • AFib, recurrent venous thromboembolism
  • ★Mechanical heart valves — DOACs not used
  • AFib, venous thromboembolism treatment & prevention
Route & onset
  • IV (immediate) or subcutaneous
  • short half-life
  • PO
  • onset 2–3 days, full effect 5–7 days
  • PO
  • rapid onset, fixed dose
Key assessment
  • Bleeding signs
  • Platelet count for HIT
  • Bleeding signs
  • Dietary vitamin K, drug interactions
  • Bleeding signs
  • Renal function (CrCl) before dosing
Monitoring labs
  • aPTT 1.5–2.5× control (UFH)
  • anti-Xa
  • ★INR 2.0–3.0 (mechanical valve 2.5–3.5)
  • No routine coagulation monitoring
Adverse effects
  • ★Heparin-induced thrombocytopenia (HIT)
  • Bleeding
  • rare early skin necrosis
  • Bleeding (GI most common)
Reversal / antidote
  • Protamine sulfate (1 mg per 100 units)
  • Vitamin K
  • PCC or FFP for major bleed
  • Andexanet alfa (Xa)
  • idarucizumab (dabig)
Contraindications & interactions
  • Active bleeding
  • prior HIT
  • ★Pregnancy — teratogenic (use heparin)
  • Severe renal/hepatic impairment
Patient teaching
  • Report unusual bleeding or bruising
  • Rotate subcutaneous sites
  • do not rub or aspirate
  • Report unusual bleeding or bruising
  • Keep vitamin K intake consistent
  • Report unusual bleeding or bruising
  • Do not stop abruptly or double doses
Class & mechanism

Heparin (UFH/LMWH)

  • Potentiates antithrombin then inhibits IIa & Xa

Warfarin

  • Vitamin K antagonist then ↓ II, VII, IX, X
Indications

Heparin (UFH/LMWH)

  • Acute venous thromboembolism, ACS, periop bridging

Warfarin

  • AFib, recurrent venous thromboembolism
  • ★Mechanical heart valves — DOACs not used
Route & onset

Heparin (UFH/LMWH)

  • IV (immediate) or subcutaneous
  • short half-life

Warfarin

  • PO
  • onset 2–3 days, full effect 5–7 days
Key assessment

Heparin (UFH/LMWH)

  • Bleeding signs
  • Platelet count for HIT

Warfarin

  • Bleeding signs
  • Dietary vitamin K, drug interactions
Monitoring labs

Heparin (UFH/LMWH)

  • aPTT 1.5–2.5× control (UFH)
  • anti-Xa

Warfarin

  • ★INR 2.0–3.0 (mechanical valve 2.5–3.5)
Adverse effects

Heparin (UFH/LMWH)

  • ★Heparin-induced thrombocytopenia (HIT)

Warfarin

  • Bleeding
  • rare early skin necrosis
Reversal / antidote

Heparin (UFH/LMWH)

  • Protamine sulfate (1 mg per 100 units)

Warfarin

  • Vitamin K
  • PCC or FFP for major bleed
Contraindications & interactions

Heparin (UFH/LMWH)

  • Active bleeding
  • prior HIT

Warfarin

  • ★Pregnancy — teratogenic (use heparin)
Patient teaching

Heparin (UFH/LMWH)

  • Report unusual bleeding or bruising
  • Rotate subcutaneous sites
  • do not rub or aspirate

Warfarin

  • Report unusual bleeding or bruising
  • Keep vitamin K intake consistent

★ marks the fact that sets a column apart.

Clinical Pearl

aPTT pairs with heparin, INR pairs with warfarin, DOACs need no routine labs — match lab to drug.

Component Topics

DOACsUnfractionated HeparinWarfarin

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