The antidote of warfarin is?

Appeared in: AIIMS Patna NO - 2020

Explanation

Warfarin is an oral anticoagulant that functions by inhibiting the synthesis of vitamin K-dependent clotting factors II, VII, IX, and X.
Vitamin K (phytonadione) serves as the direct antidote by providing the necessary substrate for the liver to resume the production of these essential clotting factors.
Administering Vitamin K effectively reverses the anticoagulant effect of warfarin, helping to control or prevent hemorrhage. However, this reversal can take 6-24 hours to become fully effective.

Option A: Protamine sulfate is the specific antidote for heparin, not warfarin.
Option C: Heparin is an anticoagulant itself and would increase the risk of bleeding if given for warfarin toxicity.
Option D: Acetyl cysteine is the antidote for acetaminophen (paracetamol) overdose.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacology: Anticoagulants and Antidotes as background academic context rather than a clinical decision trigger.
Nurses must closely monitor the International Normalized Ratio (INR) for patients on warfarin to ensure it stays within the therapeutic range (typically 2.0-3.0) to prevent both clotting and bleeding.
Patient education is a critical nursing responsibility. This includes teaching patients to recognize signs of bleeding (e.g., unusual bruising, hematuria, black tarry stools) and the importance of maintaining a consistent dietary intake of vitamin K (found in leafy green vegetables).
What if? If a patient on warfarin presents with life-threatening hemorrhage, immediate reversal is needed. In addition to IV Vitamin K, Prothrombin Complex Concentrate (PCC) or Fresh Frozen Plasma (FFP) would be administered for rapid replacement of clotting factors, as Vitamin K's effect is not immediate.

How to Approach the Question

Identify the core of the question: it asks for the specific antidote for the drug 'warfarin'.
This is a direct factual recall question from pharmacology.
Access your knowledge base about common anticoagulants and their reversal agents.
Evaluate each option based on established pharmacological pairings:
Protamine sulphate is the antidote for heparin.
Vitamin K is the antidote for warfarin.

Concept Tested & Keywords

Q65QFmWzVDSKj_xzybwI8L

E6 Pharmacology Nursing Lilley 11e Part 2 pp. 108-110, 123-125

E6 Pharmacology Katzung 16e p. 958-960

Practise the full AIIMS Patna NO - 2020

Attempt every question from this paper in a timed mock, then review the full solution for each one.