Lecture on Hematologic Medications: Anticoagulants

Introduction

• Focus on hematologic medications, particularly anticoagulants.
• Discussion of heparin and warfarin.

Heparin

• Routes of Administration:
  • IV or subcutaneous.
• Uses:
  • Stroke, DVT, pulmonary embolism, thromboembolic disorders requiring fast anticoagulation.
• Mechanism of Action:
  • Activates antithrombin which inhibits thrombus formation.
  • Prevents new clots and stops existing ones from growing.
  • Does not break down clots.

Side Effects

• Bleeding (key side effect).
• Heparin-induced thrombocytopenia (HIT):
  • Formation of microclots causing ischemia, severe bleeding risk.
• Hypersensitivity reactions.

Key Points

• Monitor aPTT levels (H looks like two Ts):
  • Target aPTT: 1.5-2 times baseline (45-80 seconds).
  • Over 100 seconds indicates excessive anticoagulation.
• Antidote: Protamine sulfate.
• Monitor for bleeding:
  • Coffee-ground emesis, tarry stools.

Warfarin (Coumadin)

• Uses:
  • Thromboembolic disorders (DVT, PE, AFib with thrombus).
  • Post-myocardial infarction.
• Mechanism of Action:
  • Antagonizes vitamin K, preventing formation of clotting factors ("Going to war on vitamin K").

Side Effects

• Bleeding.
• GI upset.
• Hepatitis.

Key Points

• Monitor PT/INR levels:
  • Therapeutic INR: 2-3.
  • PT baseline: 11-13 seconds; target: 1.5-2 times baseline (17-26 seconds).
• Antidote: Vitamin K.
• Consistent vitamin K intake is crucial:
  • Changes can affect warfarin's therapeutic level.
• Monitor for bleeding:
  • Tarry stools, coffee-ground emesis.

Conclusion

• Importance of understanding heparin and warfarin for nursing exams and practice.
• Monitoring and side effects are critical components of management.