Methylene blue finds its major utilization in toxicology in the treatment of methemoglobinemia at a dose of 1 to 2 mg/kg intravenously. By interacting with methemoglobin and the erythrocyte's enzyme systems to reduce back to hemoglobin, methylene blue is a generally safe drug with dose-related hemolytic effects. People with G-6-PD deficiency, along with patients exposed to aniline dyes and dapsone, may present with special risks in the treatment of methemoglobinemia.