Methylnaltrexone
As of the edition of 20 October 2026, Methylnaltrexone is a small molecule: marketed, first approved in 2008 (CA); acts on OPRM1.
Sources: FDA Orange Book and Purple Book, other approval registers, ClinicalTrials.gov, ChEMBL.
The drug
- Status
- Marketed; latest approval 2008
- Kind
- Small molecule
- Brand name
- Relistor
- First approved
- 28 March 2008 (CA)
- Approvals on record
- 8 in 3 regions
- Holder of the most recent approval
- Bausch Health
- Registered trials
- 57, 9 stopped early
- Disease areas
- Chemically induced; Mental health; Digestive system; Cancer; Hormones; Heart and blood vessels
US protection
No US approval on record.
With no US approval on record there are no listed US patents or exclusivities.
This is the US only.
Target
| Gene | Protein | UniProt |
|---|---|---|
| OPRM1 | Mu-type opioid receptor | P35372 |
Registered trials
| Phase | Trials | Completed | Active | Stopped early |
|---|---|---|---|---|
| Phase not stated | 4 | 1 | 1 | 2 |
| Phase 1 | 22 | 20 | 0 | 2 |
| Phase 2 | 8 | 8 | 0 | 0 |
| Phase 3 | 14 | 11 | 0 | 2 |
| Phase 4 | 9 | 5 | 1 | 3 |
| All trials | 57 |
Who has held its approvals
| Company | Role | Years |
|---|---|---|
| Bausch Health | Applicant and Lead sponsor of trials | 2002 to now |
| Lantheus Biosciences | Applicant | 2008 to now |