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Methylene blue

From Wikipedia
methylene blue
type of chemical entity
Subclass ofchemical compound Edit
Get usestaining dye Edit
Chemical formulaC₁₆H₁₈ClN₃S Edit
Canonical SMILESCN(C)C1=CC2=C(C=C1)N=C3C=CC(=[N+](C)C)C=C3S2.[Cl-] Edit
Active ingredient inMethylthioninium Chloride Proveblue Edit
World Health Organisation international non-proprietary namemethylthioninium chloride Edit
Legal status (medicine)boxed warning Edit
Pregnancy categoryUS pregnancy category X Edit
Described at URLhttps://www.sciencealert.com/can-this-blue-chemical-really-boost-your-brain-heres-what-we-know?utm_source=firefox-newtab-en-gb Edit
Subject has roleenzyme inhibitor, bactericide, essential medicine Edit

Methylene blue, dem sanso know am as methylthioninium chloride, be a medication den dye. As a medication, dem mainly dey use am treat methemoglobinemia. Specifically, dem dey use take treat methemoglobin levels wey be greater dan 30% anaa insyd wich der be symptoms despite oxygen therapy. Na dem dey use am previously for cyanide poisoning den urinary tract infections, buh dis use no longer be recommended.[1]

Dem typically dey give am by injection into a vein.[1] Common side effects dey include headache, nausea, den vomiting.

Na dem first prepare Methylene blue insyd 1876, by Heinrich Caro.[2] E dey for de World Health Organization ein List of Essential Medicines top.[3]

Side effects

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Cardiovascular[4][5] Central nervous system[4][5] Dermatologic[4][5] Gastrointestinal[4][5] Genito-urinary[4][5] Hematologic[4][5]
  • Hypertension
  • Precordial pain
  • Dizziness
  • Mental confusion
  • Headache
  • Fever
  • Staining of skin
  • Injection site necrosis (SC)
  • Fecal discoloration
  • Nausea
  • Vomiting
  • Abdominal pain
  • Discoloration of urine (doses over 80 μg)
  • Bladder irritation
  • Anemia

Methylene blue be a monoamine oxidase inhibitor (MAOI)[6] wey, if dem infuse am intravenously for doses wey dey exceed 5 mg/kg, fi result insyd serotonin syndrome if dem combined plus any selective serotonin reuptake inhibitors (SSRIs) anaa oda serotonergic drugs (e.g., duloxetine, sibutramine, venlafaxine, clomipramine, imipramine).[7]

Chemistry

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Methylene blue be a formal derivative of phenothiazine. E be a dark green powder wey dey yield a blue solution insyd water. De hydrated form get 3 molecules of water per unit of methylene blue.

Preparation

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Dem dey prepare dis compound by oxidation of 4-aminodimethylaniline insyd de presence of sodium thiosulfate make e give de quinonediiminothiosulfonic acid, reaction plus dimethylaniline, oxidation to de indamine, den cyclization make e give de thiazine:[8]

A green electrochemical procedure, wey dey use dimethyl-4-phenylenediamine per wey na dem propose sulfide ions.[9]

Light absorption properties

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Species Absorption peak Extinction coefficient (dm3/mol·cm)
MB+ (solution) 664 95000
MBH2+ (solution) 741 76000
(MB+)2 (solution) 605 132000
(MB+)3 (solution) 580 110000
MB+ (adsorbed on clay) 673 116000
MBH2+ (adsorbed on clay) 763 86000
(MB+)2 (adsorbed on clay) 596 80000
(MB+)3 (adsorbed on clay) 570 114000

References

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  1. 1.0 1.1 "Methylene Blue". The American Society of Health-System Pharmacists. Archived from the original on 10 May 2017. Retrieved 8 January 2017.
  2. Ahmad I, Aqil F (2008). New Strategies Combating Bacterial Infection (in English). John Wiley & Sons. p. 91. ISBN 978-3-527-62294-8. Archived from the original on 2017-09-18.
  3. World Health Organization (2019). World Health Organization model list of essential medicines: 21st list 2019. Geneva: World Health Organization. hdl:10665/325771. WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
  4. 4.0 4.1 4.2 4.3 4.4 4.5 Mokhlesi B, Leikin JB, Murray P, Corbridge TC (March 2003). "Adult toxicology in critical care: Part II: specific poisonings". Chest. 123 (3): 897–922. doi:10.1378/chest.123.3.897. PMID 12628894. S2CID 9962335.
  5. 5.0 5.1 5.2 5.3 5.4 5.5 Harvey JW, Keitt AS (May 1983). "Studies of the efficacy and potential hazards of methylene blue therapy in aniline-induced methaemoglobinaemia". British Journal of Haematology. 54 (1): 29–41. doi:10.1111/j.1365-2141.1983.tb02064.x. PMID 6849836. S2CID 19304915.
  6. Ramsay RR, Dunford C, Gillman PK (November 2007). "Methylene blue and serotonin toxicity: inhibition of monoamine oxidase A (MAO A) confirms a theoretical prediction". British Journal of Pharmacology. 152 (6): 946–951. doi:10.1038/sj.bjp.0707430. PMC 2078225. PMID 17721552.
  7. Gillman PK (October 2006). "Methylene blue implicated in potentially fatal serotonin toxicity". Anaesthesia. 61 (10): 1013–1014. doi:10.1111/j.1365-2044.2006.04808.x. PMID 16978328. S2CID 45063314.
  8. Berneth H (2012). "Azine Dyes". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a03_213.pub3. ISBN 978-3-527-30673-2.
  9. Maleki A, Nematollahi D (December 2009). "An efficient electrochemical method for the synthesis of methylene blue". Electrochemistry Communications (in English). 11 (12): 2261–2264. doi:10.1016/j.elecom.2009.09.040.
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