Methylnaltrexone

Opioid Antagonist — ALIMENTARY TRACT AND METABOLISM

Key facts

Methylnaltrexone is an ofp drug in the Opioid Antagonist class catalogued in DrugCentral. It was first approved by the FDA in 2008. Its mechanism of action is classified as Opioid Antagonists. DrugCentral lists 5 molecular targets, including OPRK1, OPRM1 and OPRK1. Recorded indications include Therapeutic opioid induced constipation.

• Approval status: ofp (first approved 2008 by the FDA).
• Drug class: Opioid Antagonist.
• Mechanism of action: Opioid Antagonists.
• Molecular targets: OPRK1, OPRM1, OPRK1 and OPRD1 (5 listed in DrugCentral).
• Indications: Therapeutic opioid induced constipation.
• ATC code: A06AH01 (Peripheral opioid receptor antagonists).
• Molecular formula: C21H26NO4; molecular weight 356.44 g/mol.

Indications & contraindications

Drug–disease relationships curated by DrugCentral (OMOP / SNOMED concepts).

Indications (1)

• Therapeutic opioid induced constipation

Contraindications (8)

• Acute nephropathy
• Chronic diarrhea
• Gastrointestinal obstruction
• Gastrointestinal perforation
• Gastrointestinal ulcer
• Macrocolon
• Primary malignant neoplasm of gastrointestinal tract
• Severe diarrhea

Mechanism & targets

• Mechanism of action (MoA): Opioid Antagonists
• Established pharmacologic class: Opioid Antagonist

Molecular targets (5)

Target	Gene	Action	Activity
Kappa-type opioid receptor	OPRK1	unknown	Ki 7.70
Mu-type opioid receptor	OPRM1	antagonist	Ki 7.55
Kappa-type opioid receptor	OPRK1	unknown	Ki 6.65
Delta-type opioid receptor	OPRD1	unknown	Ki 6.05
Cytochrome P450 2D6	CYP2D6	unknown	Ki 5.10

Regulatory approvals (2)

Date	Agency	Marketed as	Applicant	Orphan
2008-07-02	EMA	—	—
2008-04-24	FDA	—	SALIX PHARMS

ATC classification

ATC code	Therapeutic hierarchy
A06AH01	ALIMENTARY TRACT AND METABOLISM › DRUGS FOR CONSTIPATION › DRUGS FOR CONSTIPATION › Peripheral opioid receptor antagonists

Reported adverse-event signals

Strongest FDA FAERS disproportionality signals (log-likelihood ratio). A signal is a statistical association in spontaneous reports, not proof that the drug causes the event.

MedDRA term	LLR
Death	97.8
Abdominal pain	90.4
Pneumatosis intestinalis	39.8
Drug withdrawal syndrome	37.8
Large intestine perforation	36.0
Intestinal perforation	32.6

Chemical structure

Full physicochemical, ADMET and 3D-structure analysis of Methylnaltrexone is on its molecule page.

• Molecular formula: C₂₁H₂₆NO₄
• Molecular weight: 356.44 g/mol
• CAS number: 83387-25-1
• InChIKey: JVLBPIPGETUEET-GAAHOAFPSA-O
• PubChem CID: 5361918

C[N+]1(CC2CC2)CC[C@]23[C@H]4OC5=C(O)C=CC(C[C@@H]1[C@]2(O)CCC4=O)=C35

Frequently asked questions

Answers are generated from the structured data on this page, not written by hand.

What is Methylnaltrexone used for?

DrugCentral lists the following indications for Methylnaltrexone: Therapeutic opioid induced constipation.

How does Methylnaltrexone work?

Methylnaltrexone is classified as Opioid Antagonists; its molecular targets in DrugCentral include OPRK1, OPRM1 (antagonist), OPRK1 and OPRD1.

When was Methylnaltrexone first approved?

Methylnaltrexone was first approved by the FDA in 2008.

What drug class does Methylnaltrexone belong to?

Methylnaltrexone is in the Opioid Antagonist class.

What is the chemical formula of Methylnaltrexone?

Methylnaltrexone has the molecular formula C21H26NO4 and a molecular weight of 356.44 g/mol.

Sources

• DrugCentral drug card 4616 — structure, indications, targets, approvals, pharmacologic classes (CC BY-SA 4.0)
• ChEMBL CHEMBL1186579 — compound record and bioactivity
• PubChem CID 5361918 — chemical identifiers
• DrugBank DB06800 — drug record
• FDA UNII 0RK7M7IABE — substance identity
• DailyMed: FDA labels for Methylnaltrexone — current prescribing information (label search)
• UniProt P35372 (OPRM1) — target protein
• UniProt P41145 (OPRK1) — target protein
• UniProt P41143 (OPRD1) — target protein
• UniProt P10635 (CYP2D6) — target protein
• FDA Adverse Event Reporting System (openFDA FAERS) — adverse-event signals, as aggregated by DrugCentral

How this page is built: methodology · editorial policy & corrections.