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Relistor (METHYLNALTREXONE)
Relistor works by blocking opioid receptors in the gut to alleviate constipation.
At a glance
| Generic name | METHYLNALTREXONE |
|---|---|
| Sponsor | Salix Pharms |
| Drug class | Opioid Antagonist |
| Target | Mu-type opioid receptor |
| Modality | Small molecule |
| Therapeutic area | Pain |
| Phase | FDA-approved |
| First approval | 2008 |
| Annual revenue | 400 |
Mechanism of action
Methylnaltrexone is selective antagonist of opioid binding at the mu-opioid receptor. As quaternary amine, the ability of methylnaltrexone to cross the blood-brain barrier is restricted. This allows methylnaltrexone to function as peripherally-acting mu-opioid receptor antagonist in tissues such as the gastrointestinal tract, thereby decreasing the constipating effects of opioids without impacting opioid-mediated analgesic effects on the central nervous system (CNS).
Approved indications
- Therapeutic opioid induced constipation
Common side effects
- Abdominal pain
- Nausea
- Diarrhea
- Vomiting
- Hyperhidrosis
- Hot Flush
- Tremor
- Chills
- Abdominal distention
- Headache
- Anxiety
- Muscle spasms
Key clinical trials
- RELISTOR's Effects on Opioid-Induced Constipation
- Chronic Widespread Pain in HIV: Novel Mechanisms and Therapeutics (NA)
- Methylnatrexone In Resectable Head and Neck Squamous Cell Carcinoma (MINK). A "Window of Opportunity" Pilot Study. (PHASE4)
- Methylnaltrexone vs Naloxegol in the Treatment of Opioid-Induced Constipation (PHASE4)
- Effects of Peripherally Acting µ-opioid Receptor Antagonists on Acute Pancreatitis (PHASE2,PHASE3)
- Naloxone and Intravenous Methylnaltrexone Effects on Bladder Function (PHASE1)
- Naloxegol to Prevent Lower Gastrointestinal Paralysis in Critically Ill Adults Administered Opioids (PHASE4)
- Dasatinib, Bevacizumab, Paclitaxel in Patients With Advanced Malignancies (PHASE1)
Patents
| Patent | Expiry | Type |
|---|---|---|
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| FDA label | Mechanism, indications, dosing, boxed warnings, drug interactions |
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
| FDA Orange Book | Patents + exclusivity |
| SEC EDGAR | Revenue + earnings |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- Relistor CI brief — competitive landscape report
- Relistor updates RSS · CI watch RSS
- Salix Pharms portfolio CI