What is the primary antidote for carbon monoxide poisoning?

The primary antidote for carbon monoxide poisoning is oxygen. When carbon monoxide is inhaled, it binds to hemoglobin in the blood much more efficiently than oxygen, which leads to reduced oxygen delivery to tissues and can cause serious harm or death. Administering oxygen helps to displace carbon monoxide from hemoglobin. High-flow oxygen can significantly reduce the half-life of carbon monoxide in the bloodstream, allowing the body to eliminate it more quickly and alleviating symptoms of poisoning.

Oxygen therapy, particularly hyperbaric oxygen therapy, can be especially effective in severe cases by providing an environment where higher concentrations of oxygen are available. This therapy not only facilitates the elimination of carbon monoxide but also aids in reducing hypoxic injury to tissues that may have been affected due to the lack of oxygen.

The other choices do have roles in medicine but are not suitable as primary treatments for carbon monoxide poisoning. Activated charcoal is used for certain types of poisoning but is ineffective for carbon monoxide. Sodium thiosulfate is typically used as an antidote for cyanide poisoning, and N-acetylcysteine is primarily used for acetaminophen overdose. Thus, while these substances are important in specific contexts, oxygen remains the definitive treatment for carbon monoxide poisoning.