Tag Methylene blue
Toxicology-Conundrum-340 256

Why so blue?

A 40-year-old man presented to the emergency department with shortness of breath, chest pain and reported a pre-syncopal episode. But why so blue?

Methylene blue

Methylene Blue is the treatment of choice for symptomatic drug-induced methaemoglobinaemia (signs of hypoxia with chest pain, dyspnoea or confusion) or consider in asymptomatic patients with methaemoglobin (MetHb) levels >20%.
CCC Critical Care compendium 340

Methylene Blue CCC

CLASS heterocyclic aromatic molecule MECHANISM OF ACTION two opposite actions on Hb (1) low concentrations: methylene blue -> NADPH-dependent reduction to leucomethylene blue (due to action of methaemoglobin reductase) -> reduces methaemoglobin -> Hb(2) high concentrations: methylene blue -> converts…