Which antidote is used for warfarin overdose?

Which antidote is used for warfarin overdose?

• A. Vitamin K
• B. Naloxone
• C. Protamine sulfate
• D. Calcium gluconate

Answer: (A)

Warfarin blocks the production of vitamin K–dependent clotting factors, so reversing its effect requires supplying vitamin K. Giving vitamin K (phytonadione) replenishes the vitamin, allowing the liver to synthesize factors II, VII, IX, and X again and restore normal clotting. The amount and route depend on how urgent the reversal is: for non-bleeding cases, oral vitamin K is common; for major bleeding, rapid reversal uses intravenous vitamin K plus a concentrate of clotting factors or fresh frozen plasma. Other agents listed aren’t used to reverse warfarin—naloxone treats opioid overdose, protamine sulfate reverses heparin, and calcium gluconate isn’t an antidote for warfarin.

Warfarin blocks the production of vitamin K–dependent clotting factors, so reversing its effect requires supplying vitamin K. Giving vitamin K (phytonadione) replenishes the vitamin, allowing the liver to synthesize factors II, VII, IX, and X again and restore normal clotting. The amount and route depend on how urgent the reversal is: for non-bleeding cases, oral vitamin K is common; for major bleeding, rapid reversal uses intravenous vitamin K plus a concentrate of clotting factors or fresh frozen plasma. Other agents listed aren’t used to reverse warfarin—naloxone treats opioid overdose, protamine sulfate reverses heparin, and calcium gluconate isn’t an antidote for warfarin.