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Methylene Blue Dosage

Applies to the following strengths: 65 mg; 10 mg/mL; 5 mg/mL

The information at is not a substitute for medical advice. Always consult your doctor or pharmacist.

Usual Adult Dose for Methemoglobinemia

Drug-induced methemoglobinemia: 1 to 2 mg/kg intravenously. May repeat in one hour if necessary.

Inject intravenously very slowly over a period of several minutes to prevent local high concentration of the compound from producing additional methemoglobin.

Usual Adult Dose for Encephalopathy

Ifosfamide-induced encephalopathy (unlabeled use): (Treatment may not be necessary; encephalopathy may improve spontaneously)

Prevention: 50 mg every 6 to 8 hours

Treatment: 50 mg as a single dose or every 4 to 8 hours until symptoms resolve

Renal Dose Adjustments

No dosage adjustment recommendations available; however, should be used with caution in patients with severe renal impairment. Methylene blue is metabolized in the body to leukomethylene blue which is excreted primarily in the urine. Some unchanged drug is also excreted in the urine.

Liver Dose Adjustments

Data not available


Administer undiluted by direct IV injection over 5 to 10 minutes to prevent local high concentration of the compound from producing additional methemoglobin.

For the treatment of ifosfamide-induced encephalopathy, methylene blue may be administered either undiluted as a slow IV push over at least 5 minutes or diluted in 50 mL NS or D5W and infused over at least 5 minutes. Consider concomitant dextrose administration, especially in patients who are hypoglycemic, to ensure efficacy of methylene blue.

Do not exceed recommended dosage. Large intravenous doses of methylene blue produce nausea, abdominal and precordial pain, dizziness, headache, profuse sweating, mental confusion and the formation of methemoglobin.

Intraspinal and subcutaneous injections are contraindicated. Methylene blue should not be given by intrathecal injection.


Data not available

Other Comments

Monitor arterial blood gases; cardiac monitoring for patients with preexisting pulmonary and/or cardiac disease; CBC; methemoglobin levels using co-oximetry; pulse oximeter (will not provide accurate measurement of oxygenation when methemoglobin levels are greater than 35%); renal function; signs and symptoms of methemoglobinemia such as pallor, cyanosis, nausea, muscle weakness, dizziness, confusion, agitation, dyspnea, and tachycardia; transcutaneous O2 saturation.