Basics of Anticoagulation

May 19, 2024

Basics of Anticoagulation for Residents and Medical Students

Types of Anticoagulation Goals

  1. Prophylactic Anticoagulation: Prevents blood clots
  2. Therapeutic Anticoagulation: Treats known blood clots

Prophylactic Anticoagulation Regimens

Common Options

  • Lovenox (enoxaparin) 40 mg daily
    • Reduced dose: 30 mg for patients with AKI (Acute Kidney Injury)
  • Heparin 5000 units
    • Administered every 8 or 12 hours
    • 7500 units for obese patients
  • Obese Patients: Lovenox 0.5 mg/kg daily

Choosing the Right Regimen

  • Lovenox 40 mg: Preferred for most patients
  • Heparin or Lovenox 30 mg: For patients with AKI
  • Sequential Compression Devices (SCDs): Used for mechanical prophylaxis, especially if the patient is at high bleeding risk and can't receive pharmacologic prophylaxis. Also known as IPC (Intermittent Pneumatic Compression).

Determining the Need for DVT Prophylaxis

  • Most Patients: Especially older and less mobile, require DVT prophylaxis
  • Padua Score: Can be used to assess DVT risk

Therapeutic Anticoagulation Regimens

Common Options

  • Apixaban (Eliquis): 5 mg BID; reduced to 2.5 mg BID for patients >80 years old, weight <60 kg, or creatinine >1.5
    • Loading dose: 10 mg BID for 7 days (for DVT/PE)
  • Rivaroxaban (Xarelto): 20 mg daily; loading dose of 15 mg BID for 21 days (for DVT/PE)
    • Must be taken with food
  • Dabigatran: 150 mg BID; requires 5 days of IV anticoagulation before starting
  • Heparin Drip: Fast on and off; useful for patients requiring quick adjustments (e.g., before procedures)
  • Warfarin (Coumadin): Vitamin K antagonist; requires frequent INR monitoring (goal: 2-3). Critical to manage diet and drug interactions.
  • Lovenox (enoxaparin): 1 mg/kg BID or 1.5 mg/kg daily

Choosing Between Anticoagulants

  • Apixaban vs. Rivaroxaban:
    • Apixaban: Preferred for stable anticoagulation levels and reduced risks of thrombosis and bleeding
    • Rivaroxaban: Simpler once-daily dosing; better for patients with adherence issues, despite higher risks of thrombosis and bleeding