Methylene Blue should not be given by subcutaneous or intrathecal injection.
Methylene blue is a potent monoamine oxidase inhibitor: Methylene blue has been demonstrated to be a potent monoamine oxidase inhibitor (MAOI) and may cause potentially fatal serotonin toxicity (serotonin syndrome) when combined with serotonin reputake inhibitors (SRIs).
(4) (See DRUG INTERACTIONS.) Serotonin toxicity is characterized by development of neuromuscular hyperactivity (tremor, clonus, myoclonus and hyperreflexia, and, in the advanced stage, pyramidal rigidity); autonomic hyperactivity (diaphoresis, fever, tachycardia, tachypnoea, and mydraisis); and altered mental status (agitation, excitement, and in the advanced stage, confusion).
If methylene blue is judged to be indicated, SRIs must be ceased, prior to treatment/procedure/surgery.
Methylene Blue Injection, USP is a sterile solution of Phenothiazin_5_ium, 3, 7-bis (dimethylamino)- chloride, trihydrate.
Each mL contains Methylene Blue, USP, 10 mg in Water for Injection q.s.
pH adjusted with Hydrochloric Acid and /or Sodium Hydroxide when necessary.
The structural formula is: Formula1.jpg
REFERENCES: (1) DiSanto AR, 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;61:1086-1090 (2) Cragan JD.
Teratogen update: methylene blue.
(3) Kidd SA, Lancaster PA, Anderson JC, Boogert A, Fisher CC, Robertson R et al.
Fetal death after exposure to methylene bluedye during mid-trimester amniocentesis in twin pregnancy.
(4) Ramsay RR, Dunford C, Gillman PK.
Methylene blue and serotonin toxicity: inhibition of monoamine oxidase A (MAOA) confirms a theoretical prediction.
Br J Pharmacol.
(5) Beutler E.
1994;84:3613-3636 (6) Youngster I.
Akayzen Y, Popliski H, Shimonov J, Beig S, Berkovitch M.
Medications and glucose-6-phosphate dehydrogenase deficiency: an evidence-based review.
2010;33:713-726 IN0372 Rev.
3/11 MG# 14080 AMERICAN REGENT, INC Shirley, NY 11967 Image1.jpg
INDICATIONS AND USAGE
USE IN Pregnancy Category X: Epidemiologic evidence exists that Methylene blue is a teratogen.
An association exists between the use of methylene blue in amniocentesis and atresia of the ileum and jejunum, ileal occlusions and other adverse effects in the neonate.
(2,3) Methylene blue Injection should not be administered to pregnant women during amniocentesis due to the risk of teratogenicity and other newborn adverse effects (see CONTRAINDICATIONS).
DOSAGE AND ADMINISTRATION
0.1 to 0.2 mL per kg body weight (0.045 to 0.09 mL per pound body weight).
Inject Methylene Blue intravenously very slowly over a period of several minutes.
Methylene blue must be injected intravenously very slowly over a period of several minutes to prevent local high concentration of the compound from producing additional methemoglobin.
Do not exceed recommended dosage.
Parenteral drug products should be inspected visually for particulate matter and discoloration, whenever solution and container permit.
Store at 20 degrees-25 degrees C (68 degrees-77 degrees F); excursions permitted to 15 degrees-30 degrees C (59 degrees-86 degrees F) (See USP Controlled Room Temperature).