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Methylnaltrexone Bromide



ATC (Anatomical Therapeutic Chemical Classification)


CAS registry number (Chemical Abstracts Service)


Chemical Formula


Molecular Weight


Therapeutic Categories

Laxative: Treatment of opioid-induced constipation (OIC)

Peripheral acting µ-opioid receptor antagonist

Chemical Names

(17RS)-17-(cyclopropylmetyl)-4,5α-epoxy-3,14-dihydroxy-17-metyl-6-oxo-14beta-morphinanium bromide (WHO)

(17RS)-17-(Cyclopropylmetyl)-4,5α-epoxy-3,14-dihydroxy-17-metyl-6-oxomorphinanium bromide

(5R,9R,13S,14S)-17-Cyclopropylmetyl-3,14-dihydroxy-4,5-epoxymorphinan-6-on-metobromid (IUPAC)

Morphinanium, (17S)-17-(cyclopropylmetyl)-4,5α-epoxy-3,14-dihydroxy-17-metyl-6-oxo-, bromide, (5α)-[USAN]

Foreign Names

  • Methylnaltrexonii bromidum (Latin)
  • Methylnaltrexon bromid (German)
  • Bromure de méthylnaltrexone (French)
  • Bromuro de metilnaltrexona (Spanish)

Generic Names

  • Methylnaltrexone Bromide (OS: USAN, BAN)
  • MNTX (IS)
  • MOA-728 (IS)
  • MRZ 2663 BR (IS)

Brand Names

  • Relistor
    Bausch & Lomb Swiss, Switzerland; Link, Australia; Pfizer, Argentina; Pfizer, Canada; Salix, United States; TMC, Spain; TMC, Greece; TMC, Hungary; TMC Pharma, Belgium; TMC Pharma, France; TMC Pharma, Croatia (Hrvatska); TMC Pharma, Ireland; TMC Pharma, Portugal; TMC Pharma Services, Austria; TMC Pharma Services, Denmark; TMC Pharma Services, United Kingdom; TMC Pharma Services, Lithuania; TMC Pharma Services Ltd, Norway; TMC Pharma Services Ltd., Italy; Wyeth, Netherlands; Wyeth, Serbia; Wyeth Europe, Poland; Wyeth-Lederle, Czech Republic


BANBritish Approved Name
IUPACInternational Union of Pure and Applied Chemistry
ISInofficial Synonym
OSOfficial Synonym
Rec.INNRecommended International Nonproprietary Name (World Health Organization)
USANUnited States Adopted Name
WHOWorld Health Organization

Further information on drug naming conventions: International Nonproprietary Names.

Important Notice: The international database is in BETA release. This means it is still under development and may contain inaccuracies. It is not intended as a substitute for the expertise and judgement of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that the use of any medication in any country is safe, appropriate or effective for you. Consult with your healthcare professional before taking any medication.

Further information

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