Methylene blue

Methylene blue
INN: Methylthioninium chloride
	Molecular structure
	A volumetric flask of a methylene blue solution
Clinical data
Trade names	Urelene blue, Provayblue, Proveblue, others
Other names	CI 52015, basic blue 9
AHFS/Drugs.com	Monograph
License data	US DailyMed: Provayblue;
Pregnancy; category	AU: D; ;
Routes of; administration	By mouth, intravenous
ATC code	V03AB17 (WHO) V04CG05 (WHO);
Legal status
Legal status	US: ℞-only; EU: Rx-only;
Pharmacokinetic data
Elimination half-life	5–24 hours (IVTooltip intravenous therapy)
Excretion	Renal; In rats: 18%(POTooltip Oral administration), 28% (IV)
Identifiers
	IUPAC name 3,7-bis(Dimethylamino)-phenothiazin-5-ium chloride;
CAS Number	61-73-4 ;
PubChem CID	6099;
DrugBank	DB09241 ;
ChemSpider	5874 ;
UNII	8NAP7826UB;
KEGG	D10537; C00220;
ChEBI	CHEBI:6872 ;
ChEMBL	ChEMBL405110 ;
CompTox Dashboard (EPA)	DTXSID0023296 ;
ECHA InfoCard	100.000.469
Chemical and physical data
Formula	C16H18ClN3S
Molar mass	319.85 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES CN(C)c1ccc2c(c1)sc-3cc(=[N+](C)C)ccc3n2.[Cl-];
	InChI InChI=1S/C16H18N3S.ClH/c1-18(2)11-5-7-13-15(9-11)20-16-10-12(19(3)4)6-8-14(16)17-13;/h5-10H,1-4H3;1H/q+1;/p-1 ; Key:CXKWCBBOMKCUKX-UHFFFAOYSA-M ;
	(verify)

Methylthioninium chloride, commonly called methylene blue, is a salt used as a dye and as a medication. As a medication, it is mainly used to treat methemoglobinemia. It has previously been used for treating cyanide poisoning and urinary tract infections, but this use is no longer recommended. It has also been used to treat cases of malaria for over a century.

Methylene blue is typically given by injection into a vein. Common side effects include headache, nausea, and vomiting.

Methylene blue was first prepared in 1876, by Heinrich Caro. It is on the World Health Organization's List of Essential Medicines.

In recent years, methylene blue has been promoted for various health effects, but outside its established medical use, its safety and effectiveness are unproven; it is potentially toxic and should only be used under a doctor's prescription.