The antidote for heparin toxicity is?

Appeared in: KPSC Staff Nurse - 2016

Explanation

Protamine sulphate is the specific antidote for heparin toxicity.
It is a positively charged protein that binds to the negatively charged heparin molecule, forming an inactive complex.
This neutralization of heparin occurs rapidly, with an onset of action within 5 minutes of intravenous administration.
The standard dosage is approximately 1 mg of protamine for every 100 units of heparin to be neutralized.

Option A: Vitamin K is the antidote for warfarin (Coumadin), not heparin. It works by promoting the synthesis of vitamin K-dependent clotting factors in the liver.
Option B: Warfarin is an anticoagulant itself. Administering it would increase the bleeding risk, not reverse heparin's effects.
Option C: Thrombin is a pro-coagulant enzyme used topically to control localized bleeding during surgery. It is not a systemic reversal agent for heparin.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Antidote for Heparin Toxicity as background academic context rather than a clinical decision trigger.
Knowing the correct antidotes for anticoagulants is a critical patient safety competency for nurses, as bleeding is a major and potentially fatal complication.
Nurses must administer protamine sulphate slowly via IV infusion (not exceeding 50 mg over 10 minutes) to prevent severe hypotension, bradycardia, and anaphylactoid reactions.
What if? If a patient with heparin overdose has a known allergy to fish, the administration of protamine sulphate is much riskier. The nurse must notify the physician immediately, ensure emergency resuscitation equipment is at the bedside, and consider pre-treatment with antihistamines or corticosteroids if the benefit outweighs the risk.

How to Approach the Question

First, identify the core of the question, which is asking for the specific antidote to a medication (heparin).
This is a factual recall question common in pharmacology.
Systematically review the options provided.
Recall the mechanisms and antidotes for common anticoagulants. Associate heparin with protamine sulphate and warfarin with vitamin K.
Eliminate incorrect options: Warfarin is another anticoagulant, and thrombin is a topical agent, not a systemic antidote.
Select the option that is the specific, direct antagonist to heparin.

Concept Tested & Keywords

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

E6 Pharmacology Katzung 16e p. 958-960

Practise the full KPSC Staff Nurse - 2016

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