Anticoagulant Therapy: Heparin vs Warfarin NCLEX Guide

Heparin

• Given IV (continuous drip) or SubQ; NEVER IM
• Monitor aPTT (goal: 1.5-2.5x control, ~60-80 seconds)
• Onset: immediate (IV)
• Antidote: Protamine sulfate
• Risk: HIT (heparin-induced thrombocytopenia) - monitor platelets

Warfarin (Coumadin)

• Given PO only
• Monitor PT/INR (goal INR: 2.0-3.0, up to 3.5 for mechanical heart valves)
• Onset: 3-5 days for full effect (overlap with heparin during initiation)
• Antidote: Vitamin K (phytonadione)
• Many drug and food interactions

Client Teaching for Warfarin

• Consistent vitamin K intake (don't eliminate leafy greens, just keep intake consistent)
• Avoid alcohol, ASA, NSAIDs
• Watch for bleeding: blood in urine/stool, unusual bruising, gum bleeding
• Use soft toothbrush, electric razor
• Wear medical alert ID
• Contraindicated in pregnancy

Review our High-Alert Medications cheat sheet and Lab Values cheat sheet.