Methylene Blue

5.25 Methylene Blue
 
 

ACTIONS
Low concentrations of methylene blue will convert methemoglobin to hemoglobin (methemoglobin is toxic and gives the blood a chocolate-brown color; it does not carry oxygen). High concentrations convert ferrous iron of hemoglobin to ferric iron, thereby forming methemoglobin.

INDICATIONS
Initial treatment of methemoglobinemia.

CONTRAINDICATIONS
Renal insufficiency (excreted in urine and bile).

ADVERSE REACTIONS AND SIDE EFFECTS
Cyanosis, profuse sweating, dizziness, headache, nausea, vomiting, diarrhea (turns urine and stool blue-green). May induce hemolysis in patients deficient in glucose-6-phosphate dehydrogenase.

DOSAGE
1 mg/kg of a 1% solution. Very slow IV push of 1 mL (10 mg) every 5 minutes.