What Are the Medical Uses of Methylene Blue?

Methylene blue injection, the indications are chemical nitrite, nitrate, aniline, nitrobenzene, trinitrotoluene, benzoquinone, phenylhydrazine, and drugs containing or producing aromatic amines (acetanilide, Effective for methemoglobinemia caused by acetaminophen, phenacetin, benzocaine, etc.). It has a poor effect on methemoglobinemia caused by congenital reduced pyridine riboside methemoglobin reductase deficiency. It is not effective for abnormal hemoglobin M with methemoglobinemia. Acute cyanide poisoning can temporarily delay its toxicity.

Methylene blue injection, the indications are chemical nitrite, nitrate, aniline, nitrobenzene, trinitrotoluene, benzoquinone, phenylhydrazine, and drugs containing or producing aromatic amines (acetanilide, Effective for methemoglobinemia caused by acetaminophen, phenacetin, benzocaine, etc.). It has a poor effect on methemoglobinemia caused by congenital reduced pyridine riboside methemoglobin reductase deficiency. It is not effective for abnormal hemoglobin M with methemoglobinemia. Acute cyanide poisoning can temporarily delay its toxicity.

Drug Name

Methylene blue injection

Drug type

Prescription medicines, essential medicines, medicines for medical workers' injuries

Use classification

Cyanide poisoning antidote

Methylene blue injection ingredients

The main ingredient of this product is methylene blue, and the excipient is glucose.
Chemical name: 3,7-bis (dimethylamino) phenothiazine-5-ium trihydrate.
Chemical Structure:

Molecular formula: C ₁₆ H ₁₈ ClN ₃ S · 3H ₂ O
Molecular weight: 373.90

Methylene blue injection properties

This product is a dark blue clear liquid.

Methylene blue injection indications

This product is suitable for chemicals such as nitrite, nitrate, aniline, nitrobenzene, trinitrotoluene, benzoquinone, phenylhydrazine, etc. , Benzocaine, etc.) caused methemoglobinemia. It has a poor effect on methemoglobinemia caused by congenital reduced pyridine riboside methemoglobin reductase deficiency. It is not effective for abnormal hemoglobin M with methemoglobinemia. Acute cyanide poisoning can temporarily delay its toxicity.

Methylene blue injection specifications

2ml: 20mg;

Methylene blue injection

Intravenous injection. Nitrite poisoning, once per 1-2 mg / kg of body weight, cyanide poisoning, once per 5 to 10 mg / kg of body weight, the maximum dose is 20 mg / kg.

Adverse reaction of methylene blue injection

Excessive intravenous injection of this product can cause dizziness, nausea, vomiting, chest tightness, and abdominal pain. Excessive doses, in addition to exacerbating the symptoms mentioned above, also have headaches, decreased blood pressure, increased heart rate with arrhythmia, sweating, and disturbance of consciousness. The urine is blue after medication, and there may be tingling in the urethra during urination.

Methylene blue injection contraindications

still uncertain.

Methylene blue injection precautions

This product cannot be injected subcutaneously, intramuscularly or intrathecally. The former causes necrosis and the latter causes paralysis. 6-Phosphate-glucose dehydrogenase deficiency patients and children using this product in excessive doses can cause hemolysis. It should be used with caution in patients with renal insufficiency.
This product is a 1% solution, which needs to be diluted with 40ml of 25% glucose injection solution and slowly injected intravenously (10 minutes after injection). For methemoglobinemia caused by chemicals and drugs, if the skin and mucosa cyanosis does not subside for 30 to 60 minutes, the medication can be repeated. Congenital reduced pyridine riboside methemoglobin reductase deficiency caused by methemoglobinemia, daily 0.3g orally and large doses of vitamin C.

Methylene blue injection for pregnant and lactating women

This experiment was not performed and there are no reliable references.

Methylene blue injection for children

1. Cyanide poisoning: 10 mg / kg at a time, plus 20 to 40 ml of 5% glucose injection, slowly intravenously. The cyanosis disappeared around the mouth, and then sodium thiosulfate was given.
2. Nitric acid and nitrite poisoning: 1 ~ 2mg / kg once, slowly intravenously (more than 5 ~ 10 minutes).

Methylene blue injection for the elderly

This experiment was not performed and there are no reliable references.

Methylene blue injection drug interactions

This experiment was not performed and there are no reliable references.

Methylene blue injection overdose

Excessive intravenous injection (0.5g) can cause headache, dizziness, pain in the precardiac area, sweating, unconsciousness, low T wave or inverted.

Methylene blue injection pharmacology and toxicology

Methylene blue itself is an oxidant and has two different effects on hemoglobin according to its different concentration in the body. At low concentrations, hydrogen ions in the 6-phosphate-glucose dehydrogenation process are transferred to methylene blue via reduced pyridine nucleoside triphosphate, which transforms them into reduced white methylene blue; white methylene blue transmits hydrogen ions again The methemoglobin with ferric iron is reduced to normal hemoglobin with ferric iron, and the white methylene blue is oxidized to methylene blue. The reduction-oxidation process of methylene blue can be repeated. At high concentrations, methylene blue cannot be completely reduced to white methylene blue, so it plays an oxidizing role, oxidizing normal hemoglobin to methemoglobin. Since methemoglobin is easily combined with CN- to form cyanated methemoglobin, but the two dissociate after a few minutes, it can only temporarily inhibit the toxicity of CN- to tissue poisoning.

Pharmacokinetics of methylene blue injection

Methylene blue has a rapid effect after intravenous injection, and is basically excreted in the urine without being metabolized, and can be absorbed orally under the pH conditions of the gastrointestinal tract. And quickly reduced to white methylene blue in the tissue. Within 6 days, 74% were excreted by the urine, 22% of which were in the original form, and the rest were white methylene blue, and some may be methylated. A small amount of methylene blue passes through the bile and is excreted from the feces.

Methylene blue injection storage

Protected from light and sealed.

Methylene blue injection packaging

Low borosilicate glass ampoules, 5 sticks / box.

Methylene blue injection expiration date

36 months

Methylene blue injection standard

"Chinese Pharmacopoeia" 2010 edition two ^[1]