What is the antidote for Warfarin (Coumadin)?
Explanation & Rationale
Choice A reason: Warfarin inhibits vitamin K-dependent blood clotting factors, prolonging coagulation. Vitamin K reverses this by restoring factor synthesis in the liver, normalizing clotting. Administered orally or intravenously, it counteracts warfarin’s anticoagulant effect in cases of overdose or bleeding, making this the correct antidote. Choice B reason: Protamine sulfate is the antidote for heparin, not warfarin. It binds to heparin, neutralizing its anticoagulant effect by forming an inactive complex. Warfarin acts via a different mechanism (vitamin K inhibition), so protamine sulfate is ineffective, making this choice incorrect for warfarin overdose. Choice C reason: Narcan (naloxone) reverses opioid overdoses by competitively binding to opioid receptors, restoring respiration. It has no effect on warfarin’s anticoagulant mechanism, which involves vitamin K-dependent clotting factors, making this choice irrelevant and incorrect for treating warfarin toxicity. Choice D reason: Flumazenil reverses benzodiazepine overdoses by antagonizing their sedative effects at GABA receptors. It does not affect warfarin’s inhibition of clotting factor synthesis, which requires vitamin K to reverse. This makes flumazenil incorrect for managing warfarin-related bleeding or toxicity.