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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Side-by-side3 compared
Focus
Comparevs
Dimension
Heparin (UFH/LMWH)
Warfarin
DOACs
Class & mechanism
- Boosts antithrombin → inhibits IIa & Xa
- Vitamin K antagonist → ↓ II, VII, IX, X
- Direct Xa (–xabans) or IIa (dabigatran)
Indications
- VTE treatment & prevention
- ACS / acute MI
- Periop bridging
- AFib stroke prevention
- ★Mechanical heart valves — DOACs not used
- VTE treatment & prevention
- AFib stroke prevention
- VTE treatment & prevention
- Preferred in nonvalvular AFib
Route & onset
- IV (immediate) or subcutaneous
- Short half-life (UFH 1–2 hr)
- 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
- CrCl before dosing (dabigatran ~80% renal)
Monitoring labs
- aPTT 1.5–2.5× control (UFH)
- Anti-Xa level (LMWH, if needed)
- ★INR 2.0–3.0 (mechanical valve 2.5–3.5)
- No routine coagulation monitoring
Adverse effects
- ★Heparin-induced thrombocytopenia (HIT)
- Bleeding
- Bleeding
- Skin necrosis (rare, early)
- Bleeding
- Dyspepsia (dabigatran)
Reversal / antidote
- Protamine sulfate (1 mg per 100 units)
- Vitamin K
- PCC or FFP for major bleed
- Andexanet alfa (Xa inhibitors)
- Idarucizumab (dabigatran)
Contraindications & interactions
- Active bleeding
- History of HIT
- ★Pregnancy — teratogenic (use heparin)
- Active bleeding
- Severe renal/hepatic impairment
- Active bleeding
Patient teaching
- Report unusual bleeding or bruising
- Rotate subcutaneous sites
- Do not rub or aspirate the site
- Report unusual bleeding or bruising
- Keep vitamin K intake consistent
- Report unusual bleeding or bruising
- Short half-life — never skip doses
Class & mechanism
Heparin (UFH/LMWH)
- Boosts antithrombin → inhibits IIa & Xa
Warfarin
- Vitamin K antagonist → ↓ II, VII, IX, X
Indications
Heparin (UFH/LMWH)
- VTE treatment & prevention
- ACS / acute MI
- Periop bridging
Warfarin
- AFib stroke prevention
- ★Mechanical heart valves — DOACs not used
- VTE treatment & prevention
Route & onset
Heparin (UFH/LMWH)
- IV (immediate) or subcutaneous
- Short half-life (UFH 1–2 hr)
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 level (LMWH, if needed)
Warfarin
- ★INR 2.0–3.0 (mechanical valve 2.5–3.5)
Adverse effects
Heparin (UFH/LMWH)
- ★Heparin-induced thrombocytopenia (HIT)
- Bleeding
Warfarin
- Bleeding
- Skin necrosis (rare, early)
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
- History of HIT
Warfarin
- ★Pregnancy — teratogenic (use heparin)
- Active bleeding
Patient teaching
Heparin (UFH/LMWH)
- Report unusual bleeding or bruising
- Rotate subcutaneous sites
- Do not rub or aspirate the site
Warfarin
- Report unusual bleeding or bruising
- Keep vitamin K intake consistent
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Clinical Pearl
aPTT pairs with heparin, INR pairs with warfarin, DOACs need no routine labs — match lab to drug.
Component Topics
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Go further
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