Q: What is the next level of treatment in methemoglobinemia, if Methylene blue  fails?

Answer: Exchange transfusion

Methylene blue is the primary and emergent treatment for symptomatic methemoglobinemia. It should be remembered that Methylene Blue cannot be used in patients with G6PD deficiency. Exchange transfusion should be considered for patients who do not respond to methylene blue or have G6PD- deficiency.