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methylthioninium chloride

Lumeblue (previously Methylthioninium chloride Cosmo), Methylthioninium chloride Proveblue · ATC code V04CX

Also known as: Methylthioniniumchlorid

Key facts
Active substance
methylthioninium chloride
Drug class
Urea c-13
ATC code
V04CX
Authorisation
centrally authorised across the EU (EMA)
Dosage forms
Lumeblue 25 mg prolonged-release tablets · Methylthioninium chloride Proveblue 5 mg/ml solution for injection
Marketing authorisation holder
Cosmo Technologies Ltd, Provepharm SAS
Information as of
2026-10-27

Key facts

Methylthioninium chloride (methylene blue) is used as an injection (Proveblue) for acute drug- or chemical-induced methaemoglobinaemia and as prolonged-release tablets (Lumeblue) to enhance visualisation of colorectal lesions during colonoscopy.

What it is used for

  • Proveblue: acute symptomatic treatment of medicinal and chemical product-induced methaemoglobinaemia in adults, children and adolescents
  • Lumeblue: enhanced visualisation of colorectal lesions in adults undergoing screening or surveillance colonoscopy

Dosing

  • Proveblue, adults: 1 to 2 mg per kg body weight intravenously over 5 minutes; a repeat dose may be given one hour later
  • Proveblue: maximum cumulative dose 7 mg/kg; 4 mg/kg in aniline- or dapsone-induced methaemoglobinaemia; treatment does not usually exceed one day
  • Proveblue: dosing in children and renal impairment in the full text
  • Lumeblue: total dose 200 mg (eight 25 mg tablets) during or after PEG bowel cleansing, completed the evening before colonoscopy
  • Lumeblue: caution in moderate to severe renal impairment

Contraindications

  • Hypersensitivity to the active substance (Proveblue: also other thiazine dyes; Lumeblue: also peanut or soya)
  • Glucose-6-phosphate dehydrogenase deficiency
  • Proveblue: nitrite-induced methaemoglobinaemia during cyanide poisoning, chlorate poisoning, NADPH reductase deficiency
  • Lumeblue: pregnancy and lactation

Important warnings

  • Serotonin syndrome with serotonergic medicines (reported after intravenous use)
  • Blue-green colouring of urine and faeces and blue skin, which may hinder diagnosis of cyanosis
  • Pulse oximetry may give inaccurate readings; co-oximetry preferred
  • Proveblue: inject very slowly; may exacerbate haemolysis; photosensitivity possible

Side effects

  • Lumeblue: commonly chromaturia and discoloured faeces, transient nausea and vomiting
  • Proveblue: dizziness, paraesthesia, dysgeusia, nausea, skin discoloration, sweating, injection site pain
  • Intravenous use has occasionally caused hypotension and cardiac arrhythmias, rarely fatal

Interactions

  • Serotonergic medicines (SSRIs, SNRIs, bupropion, buspirone, clomipramine, mirtazapine, venlafaxine) and opioids such as tramadol: risk of serotonin syndrome
  • Methylthioninium chloride is a potent reversible inhibitor of monoamine oxidase

Pregnancy and breastfeeding

  • Lumeblue is contraindicated in pregnancy; Proveblue only if clearly necessary, e.g. life-threatening methaemoglobinaemia
  • After Proveblue, breast-feeding should be discontinued for up to 8 days

Summary of the official product information, written with AI (Claude, Anthropic) on 2026-10-28. Every number was checked automatically against the original text. Not reviewed by a physician – the full official text is authoritative.

Full official text →

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For patients

Package leaflet, verbatim

Package leaflet for patients →

Authorisation and brand names by country

Medicines with exactly this active-substance composition, as listed in the national registers – alphabetical and without ranking. Whether a product is currently available is not shown here.

EU – centrally authorised (all member states)

Source: European Medicines Agency (EMA), product information

Brand names in 5 more European countries
Belgium
Metiblo
Iceland
Proveblue
Italy
Metiltioninio Cloruro Bioindustria L.I.M., Metiltioninio Cloruro Monico, Metiltioninio Cloruro S.A.L.F.
Liechtenstein
Proveblue
Norway
Proveblue

EMA – Article 57 product data (EU/EEA), 2026-10-28

Medelix receives no money from pharmaceutical companies. Brand names are listed alphabetically and without ranking.

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Sources

  1. European Medicines Agency. Lumeblue (previously Methylthioninium chloride Cosmo) – EPAR, Product Information (OF THE TEXT Detailed information on this medicinal product i). 2026-10-27. https://www.ema.europa.eu/en/documents/product-information/lumeblue-epar-product-information_en.pdf
  2. European Medicines Agency. Methylthioninium chloride Proveblue – EPAR, Product Information (OF THE TEXT Detailed information on this medicinal product i). 2026-10-27. https://www.ema.europa.eu/en/documents/product-information/methylthioninium-chloride-proveblue-epar-product-information_en.pdf
  3. Wikidata (CC0): ATC V04CX.

Editorial: Medelix editorial team · last updated 2026-10-27 · How these pages are made · Report an error

Source: European Medicines Agency (EMA), product information. Not advertising, not a treatment recommendation. For questions about your own treatment, ask your doctor or pharmacist.