Parenteral Manual

Methylene Blue

Disclaimer: Official controlled document is the CHEO online copy. It is the responsibility of user to ensure that any paper copy version is the same as the online version before use.

Alternate Name(s): 
Tetramethylthionine chloride trihydrate
Original Date: 
March 2007
  • Antidote for cyanide poisoning and drug induced methemoglobinemia.
  • As a dye in diagnostic procedures.
Reconstitution and Stability: 
  • Available as 1% solution (10 mg/mL).
  • Store at room temperature.

Solution Compatible: 0.9% NaCl

Incompatible: Do not dilute with other IV solutions


(For approved routes of administration by nursing personnel, refer to Policy for the Administration of Intravenous Medications.)

IV Direct

YES, by physician ONLY


Undiluted or diluted in NS

Inject over 5 minutes

IV Intermittent Infusion NO
IV Continuous Infusion NO

(For neonatal dosages, refer to Neonatal IV Drug Manual.)

  • Usual IV dose is 1-2 mg/kg injected over several minutes.
  • Alternatively, an IV dose of 25-50 mg/m2 has been administered.
  • Dose may be repeated in one hour if necessary.
Potential hazards of parenteral administration: 
  • Inject slowly to minimize formation of additional methemoglobinemia.
  • May cause nausea, vomiting, abdominal and chest pain, dizziness, headache, profuse sweating, confusion and hypertension.
  • With very high doses methemoglobinemia and hemolysis may occur.
  • Monitoring: methemoglobin levels, blood pressure, serum bilirubin (unconjugated) and anemia.
  • Use with caution in patients with glucose-6-phosphate dehydrogenase deficiency.
  • Contraindicated in severe renal impairment.
  • Do not inject subcutaneously or intrathecally as necrotic abscesses (subQ) and neural damage (I.T.) including paraplegia have occurred.

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