What is the main treatment for methemoglobinemia?

Methylene blue is the primary treatment for methemoglobinemia because it acts as a reducing agent that facilitates the conversion of methemoglobin back to hemoglobin. In methemoglobinemia, the iron in hemoglobin is oxidized from the ferrous (Fe2+) to the ferric (Fe3+) state, which prevents oxygen from being effectively transported throughout the body. Methylene blue donates electrons and helps to reduce the ferric iron back to the ferrous form, thus restoring the oxygen-carrying capacity of hemoglobin.

The treatment is particularly effective in cases of symptomatic methemoglobinemia or when methemoglobin levels exceed a certain threshold. While supplemental oxygen therapy may help improve oxygen delivery in general, it does not address the underlying problem of the methemoglobin itself. Corticosteroids and vitamin K are not indicated in the treatment of methemoglobinemia and do not have any therapeutic role in reversing the condition. Thus, methylene blue stands out as the definitive treatment for this condition.