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Medication Safety Issues
Due to potential toxicity (hemolytic anemia), do not use methylene blue to color enteral feedings to detect aspiration.
Pronunciation
(METH i leen bloo)
Generic Available
Yes
Pharmacologic Category
Use: Labeled Indications
Antidote for cyanide poisoning and drug-induced methemoglobinemia, indicator dye
Use: Unlabeled/Investigational
Treatment/prevention of ifosfamide-induced encephalopathy; topically, in conjunction with polychromatic light to photoinactivate viruses such as herpes simplex; alone or in combination with vitamin C for the management of chronic urolithiasis
Pregnancy Risk Factor
C
Contraindications
Hypersensitivity to methylene blue or any component of the formulation; intraspinal injection; renal insufficiency
Warnings/Precautions
Concerns related to adverse effects:
• Anemia: Continued use can cause profound anemia.
• Methemoglobinemia: At high doses or in patients with G6PD-deficiency and infants, methylene blue may catalyze the oxidation of ferrous iron in hemoglobin to ferric iron causing paradoxical methemoglobinemia. Monitor methemoglobin concentrations regularly during administration.
Special populations:
• G6PD deficiency: Use with caution in patients with G6PD deficiency.
• Young patients: Use with caution in young patients.
Other warnings/precautions:
• Administration: Do not inject SubQ or intrathecally.
• Enteral feedings: Methylene blue should not be added to enteral feeding products (Durfee, 2006; Wessel, 2005). Safety and efficacy have not been established.
Adverse Reactions
Frequency not defined.
Cardiovascular: Hypertension, precordial pain
Central nervous system: Dizziness, mental confusion, headache, fever
Dermatologic: Staining of skin
Gastrointestinal: Fecal discoloration (blue-green), nausea, vomiting, abdominal pain
Genitourinary: Discoloration of urine (blue-green), bladder irritation
Hematologic: Anemia
Miscellaneous: Diaphoresis
Drug Interactions
There are no known significant interactions.
Mechanism of Action
Weak germicide in low concentrations, hastens the conversion of methemoglobin to hemoglobin; has opposite effect at high concentrations by converting ferrous ion of reduced hemoglobin to ferric ion to form methemoglobin; in cyanide toxicity, it combines with cyanide to form cyanmethemoglobin preventing the interference of cyanide with the cytochrome system
Pharmacodynamics/Kinetics
Onset of action: Reduction of methemoglobin: I.V.: 30-60 minutes
Absorption: Oral: 53% to 97%
Excretion: Urine and feces
Dosage
Children and Adults: Methemoglobinemia: I.V.: 1-2 mg/kg or 25-50 mg/m2 over several minutes; may be repeated in 1 hour if necessary
Adults: Ifosfamide-induced encephalopathy (unlabeled use): Note: Treatment may not be necessary; encephalopathy may improve spontaneously: I.V.:
Prevention: 50 mg every 6-8 hours
Treatment: 50 mg as a single dose or every 4-8 hours until symptoms resolve
Administration: I.V.
Administer undiluted by direct I.V. injection over several minutes. For the treatment of ifosfamide-induced encephalopathy, methylene blue may be administered either undiluted as a slow I.V. 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.
Monitoring Parameters
Arterial blood gases; cardiac monitoring (patients with pre-existing pulmonary and/or cardiac disease); CBC; methemoglobin levels (co-oximetry yields a direct and accurate measure of methemoglobin levels); pulse oximeter (will not provide accurate measurement of oxygenation when methemoglobin levels are >35%); renal function; signs and symptoms of methemoglobinemia such as pallor, cyanosis, nausea, muscle weakness, dizziness, confusion, agitation, dyspnea and tachycardia; transcutaneous O2 saturation
Reference Range
Methemoglobin levels: Note: The level of methemoglobin is expressed as a percent of total hemoglobin affected.
10% to 25%: Cyanosis
35% to 40%: Fatigue, dizziness, dyspnea, headache, tachycardia
60%: Lethargy, stupor
>70%: Death (adults)
Additional Information
Skin stains may be removed using a hypochlorite solution.
Dental Health: Effects on Dental Treatment
No significant effects or complications reported
Dental Health: Vasoconstrictor/Local Anesthetic Precautions
No information available to require special precautions
Mental Health: Effects on Mental Status
May cause confusion or dizziness
Mental Health: Effects on Psychiatric Treatment
None reported
Dosage Forms
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Injection, solution: 10 mg/mL (1 mL, 10 mL)
References
Albert M, Lessin MS, and Gilchrist BF, “Methylene Blue: Dangerous Dye for Neonates,” J Pediatr Surg, 2003, 38(8):1244-5.
Burnakis TG, “Inadvertent Substitution of Methylene Blue for Indigo Carmine to Detect Premature Rupture of Membranes,” Hosp Pharm, 1995, 30(4):336-8.
David KA and Picus J, “Evaluating Risk Factors for the Development of Ifosfamide Encephalopathy,” Am J Clin Oncol, 2005, 28(3):277-80.
Dawson AH and Whyte IM, “Management of Dapsone Poisoning Complicated by Methaemoglobinaemia,” Med Toxicol Adverse Drug Exp, 1989, 4(5):387-92.
DiSanto AR and Wagner JG, “Pharmacokinetics of Highly Ionized Drugs II: Methylene Blue - Absorption, Metabolism, and Excretion in Man and Dog After Oral Administration,” J Pharm Sci, 1972, 61(7):1086-90.
Durfee SM, Gallagher-Allred C, Pasquale JA, “Standards for Specialized Nutrition Support for Adult Residents of Long-Term Care Facilities,” Nutr Clin Pract, 2006, 21(1):96-104.
Harvey JW and Keitt AS, “Studies of the Efficacy and Potential Hazards of Methylene Blue Therapy in Aniline-Induced Methaemoglobinaemia,” Br J Haematol, 1983, 54(1):29-41.
Jahns BE, Rynn KO, and Paloucek FP, “Interference of Methylene Blue (MthB) in the Determination of Whole Blood Methemoglobin (MtHgb) Concentrations,” Vet Hum Toxicol, 1994, 36:342.
Maloney JP, Ryan TA, Brasel KJ, et al, “Food Dye Use in Enteral Feedings: A Review and a Call for a Moratorium,” Nutr Clin Pract, 2002, 17(3):169-81.
Mokhlesi B, Leikin JB, Murray P, et al, “Adult Toxicology in Critical Care: Part II: Specific Poisonings,” Chest, 2003, 123(3):897-922.
Patel PN, “Methylene Blue for Management of Ifosfamide-Induced Encephalopathy,” Ann Pharmacother, 2006, 40(2):299-303.
Pelgrims J, DeVos F, Van den Brande J, et al, “Methylene Blue in the Treatment and Prevention of Ifosfamide-Induced Encephalopathy: Report of 12 Cases and a Review of the Literature,” Br J Cancer, 2000, 82(2) 291-4.
Preiser JC, Lejeune P, Roman A, et al, “Methylene Blue Administration in Septic Shock: A Clinical Trial,” Crit Care Med, 1995, 23(2):259-64.
Sills M and Zinkham W, “Methylene Blue-Induced Heinz Body Hemolytic Anemia,” Arch Pediatr Adolesc Med, 1994, 148(3):306-10.
Turner AR, Duong CD, and Good DJ, “Methylene Blue for the Treatment and Prophylaxis of Ifosfamide-Induced Encephalopathy,” Clin Oncol (R Coll Radiol), 2003, 15(7):435-9.
Wessel J, Balint J, Crill C, et al, “Standards for Specialized Nutrition Support: Hospitalized Pediatric Patients,” Nutr Clin Pract, 2005, 20(1):103-116.
Wright RO, Lewander WJ, and Woolf AD, “Methemoglobinemia: Etiology, Pharmacology, and Clinical Management,” Ann Emerg Med, 1999, 34(5):646-56.
Zulian GB, Tullen E, and Maton B, “Methylene Blue for Ifosfamide-Associated Encephalopathy,” N Engl J Med, 1995, 332(18):1239-40.
Lexi-Comp.com
Last full review/revision September 2009
Content last modified September 2009
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