Antidote for heparin is:

Appeared in: Combined AIIMS - 2020 (Jodhpur, Bhopal, Patna, Raipur)

Explanation

Protamine sulfate is the specific pharmacological antidote for heparin overdose.
It functions as a chemical antagonist, where the positively charged protamine molecule binds to the negatively charged heparin molecule.
This binding forms a stable, inactive complex, which neutralizes the anticoagulant effect of heparin.
The reversal of heparin's effects is rapid, beginning within 5 minutes of intravenous administration.
The standard dosage is 1 mg of protamine for every 100 units of heparin estimated to be remaining in the body.

Option A: Naloxone is an opioid antagonist and has no effect on heparin.
Option B: Flumazenil is a benzodiazepine antagonist and does not reverse the effects of heparin.
Option C: Digibind (Digoxin Immune Fab) is specific to digoxin and has no interaction with heparin.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacology: Antidotes for Anticoagulants as background academic context rather than a clinical decision trigger.
Nurses must be able to rapidly identify signs of heparin overdose (e.g., hematuria, melena, petechiae, bleeding from gums) and be prepared to administer the correct antidote promptly.
Protamine sulfate must be administered via slow IV infusion (not exceeding 50 mg over 10 minutes) to prevent severe adverse reactions, including hypotension, bradycardia, and anaphylactoid responses.
Before administering protamine, the nurse should confirm the order, check for patient allergies (especially to fish, as protamine is derived from fish sperm), and ensure emergency resuscitation equipment is available.

How to Approach the Question

This is a direct factual recall question testing pharmacological knowledge.
First, identify the key drug in the question stem: 'heparin'.
Recall the classification and function of heparin. It is a potent anticoagulant used to prevent blood clots.
Systematically evaluate the options provided, searching for the specific antagonist (antidote) for heparin.
Recognize that Protamine sulfate is the known, specific antidote for heparin.
To confirm the answer, mentally verify the uses of the other options: Naloxone is for opioids, Flumazenil is for benzodiazepines, and Digibind is for digoxin. This process of elimination confirms that Protamine sulfate is the only correct choice.

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 Combined AIIMS - 2020 (Jodhpur, Bhopal, Patna, Raipur)

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