What reverses heparin?

• A. Protamine sulfate reverses heparin
• B. Vitamin K reverses heparin
• C. Desmopressin reverses heparin
• D. Platelet transfusion reverses heparin

Answer: (A)

Reversing heparin relies on a specific agent that neutralizes its anticoagulant effect. Protamine sulfate is a positively charged molecule that binds to heparin, forming a stable complex and stopping its activity. This effectively restores normal clotting, particularly after procedures using unfractionated heparin. Low-molecular-weight heparin is only partially reversed by protamine, and other options don’t neutralize heparin—vitamin K reverses warfarin, desmopressin helps with certain platelet function issues, and platelet transfusion aids hemostasis without removing heparin’s effect. So the best answer is protamine sulfate.