Final answer:
Vitamin K is the antidote for warfarin sodium overdose used to reverse its anticoagulant effects.
Step-by-step explanation:
The nurse is aware that the drug that will most likely be used in the treatment of warfarin sodium overdose is vitamin K. Warfarin, also known as Coumadin, is an anticoagulant that prevents blood clotting and is used to treat conditions such as stroke or heart attack. However, overdosing on warfarin can lead to excessive bleeding, and vitamin K serves as the antidote by helping to promote blood clotting and reversing the effects of the overdose. Other options like aspirin and heparin are also anticoagulants and would not be used as treatments for an overdose of warfarin. Protamine sulfate is used to reverse the effects of heparin but not warfarin.