High-Alert Anticoagulants: Monitoring Heparin vs Warfarin Therapy

Understanding the different pathways and monitoring protocols for standard anticoagulants prevents bleeding complications.

Heparin (Unfractionated)

• Route: Subcutaneous or IV.
• Lab Monitor: Activated partial thromboplastin time (aPTT). Normal: 30-40 seconds; Therapeutic: 1.5 - 2.5 times the control (approx 60-80 seconds).
• Antidote: Protamine Sulfate.

Warfarin (Coumadin)

• Route: Oral.
• Lab Monitor: Prothrombin time (PT) and International Normalized Ratio (INR). Therapeutic INR is 2.0 - 3.0 for most indications.
• Antidote: Vitamin K (Phytonadione).