The antidote for Heparin is?

Appeared in: SCTIMST Staff Nurse - 2015 (Set-A)

Explanation

Protamine sulfate is the specific antidote used to reverse the anticoagulant effects of heparin.
It works by binding with the strongly acidic, negatively charged heparin to form a stable, inactive salt, thereby neutralizing its effects.
The dosage is based on the amount of heparin received and the time elapsed since administration, typically 1 mg of protamine for every 100 units of heparin.
The reversal of heparin's anticoagulant properties occurs in as little as 5 minutes after IV administration of protamine.

Option A: Calcium gluconate is not an antidote for heparin. It is primarily used to treat magnesium sulfate toxicity, hyperkalemia (by stabilizing the cardiac membrane), and hypocalcemia.
Option B: Vitamin K is the antidote for the oral anticoagulant warfarin (Coumadin), not heparin. It works by helping the liver synthesize vitamin K-dependent clotting factors.
Option D: Atropine is an anticholinergic drug. It is used to treat symptomatic bradycardia and certain types of poisoning (e.g., organophosphate), not for reversing anticoagulation.

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 know common antidotes for emergency situations. Rapid reversal of anticoagulation can be life-saving in cases of major bleeding or before emergency surgery.
Before administering protamine sulfate, the nurse must verify for patient allergies, especially to fish (protamine is derived from fish sperm), and previous use of NPH insulin, as these increase the risk of an anaphylactic reaction.
What if? If a patient is bleeding but the anticoagulant is warfarin instead of heparin, administering protamine sulfate would be ineffective. The correct intervention would be to administer Vitamin K and potentially Fresh Frozen Plasma (FFP) or Prothrombin Complex Concentrate (PCC).

How to Approach the Question

This is a direct recall question testing knowledge of pharmacology, specifically antidotes.
First, identify the key drug in the question stem: 'Heparin'.
Next, recall the specific antidote associated with heparin.
Systematically evaluate each option provided:
Calcium gluconate: Recall its use for magnesium toxicity or hyperkalemia.
Vitamin K: Recall its use as the antidote for warfarin.

Concept Tested & Keywords

Q0CV9tuezyUms96_jE6fnK

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

E6 Harper's Illustrated Biochemistry2023 (pp 26-793 of 813) p. 669-671

Practise the full SCTIMST Staff Nurse - 2015 (Set-A)

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