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methylnaltrexone bromide

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methylnaltrexone bromide

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Also known as naltrexone methylbromide

Methylnaltrexone (MNTX, brand name Relistor), used in form of methylnaltrexone bromide (INN, USAN, BAN), is a medication that acts as a peripherally acting μ-opioid receptor antagonist that acts to reverse some of the side effects of opioid drugs such as constipation without significantly affecting pain relief or precipitating withdrawals. Because MNTX is a quaternary ammonium cation, it cannot cross the blood–brain barrier, and so has antagonist effects throughout the body, counteracting effects such as itching and constipation, but without affecting opioid effects in the brain such as pain r

Chemical data

Formula
C21H26BrNO4
Molecular weight
436.3 g/mol
IUPAC name
(4R,4aS,7aR,12bS)-3-(cyclopropylmethyl)-4a,9-dihydroxy-3-methyl-2,4,5,6,7a,13-hexahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-3-ium-7-one bromide
SMILES
C[N+]1(CC[C@]23[C@@H]4C(=O)CC[C@]2([C@H]1CC5=C3C(=C(C=C5)O)O4)O)CC6CC6.[Br-]
InChIKey
IFGIYSGOEZJNBE-KNLJMPJLSA-N
Polar surface area
66.8 Ų
H-bond donors
2
H-bond acceptors
5
Formal charge
0

via PubChem

Wikidata facts

Has use
medication
Show 1 more fact
defined daily dose
6
Sources (3)

via Wikidata · CC0

~7 min read

Encyclopedic overview

10 sections
Contents
  • Medical uses
  • Mechanism of action
  • Side effects
  • History
  • Society and culture
  • Approval
  • Forms
  • See also
  • References
  • Further reading

Methylnaltrexone (MNTX, brand name Relistor), used in form of methylnaltrexone bromide (INN, USAN, BAN), is a medication that acts as a peripherally acting μ-opioid receptor antagonist that acts to reverse some of the side effects of opioid drugs such as constipation without significantly affecting pain relief or precipitating withdrawals. Because MNTX is a quaternary ammonium cation, it cannot cross the blood–brain barrier, and so has antagonist effects throughout the body, counteracting effects such as itching and constipation, but without affecting opioid effects in the brain such as pain relief. However, since a significant fraction (up to 60%) of opioid analgesia can be mediated by opioid receptors on peripheral sensory neurons, particularly in inflammatory conditions such as arthritis, traumatic or surgical pain, MNTX may increase pain under such circumstances.

==Medical uses== Methylnaltrexone is approved for the treatment of opioid-induced constipation in chronic non cancer pain or when ordinary laxatives have failed.

Excerpted from Wikipedia’s “methylnaltrexone bromide” article, available under the CC BY-SA 4.0 licence.