Which medication is specifically used for reversing the effects of acetaminophen toxicity?

N-acetylcysteine is the specific antidote used to reverse the effects of acetaminophen toxicity. When acetaminophen is ingested in amounts exceeding the therapeutic dose, it can lead to severe liver damage due to the accumulation of toxic metabolites. N-acetylcysteine works primarily by replenishing glutathione levels in the liver, which helps neutralize the harmful metabolites and facilitates their excretion. This intervention is most effective when administered within eight hours of acetaminophen ingestion, but it can still provide benefits even if given later.

Activated charcoal is a general treatment for certain types of poisoning and can help absorb various toxins if given soon after ingestion, but it does not specifically target acetaminophen-related effects like N-acetylcysteine does. Gastric lavage may also be considered in acute overdoses, but it is less commonly used today due to potential complications and because it does not provide the specific therapeutic benefit that N-acetylcysteine does. Vitamin K serves as an antidote for warfarin and certain anticoagulant overdoses, making it irrelevant in the context of acetaminophen toxicity.

Thus, N-acetylcysteine is the appropriate choice for treating acetaminophen overdose,