Allopurinol
As of the edition of 20 October 2026, Allopurinol is a small molecule: marketed, first approved in 1966 (CH); acts on XDH; no US protection of its own is listed.
Sources: FDA Orange Book and Purple Book, other approval registers, ClinicalTrials.gov, ChEMBL.
The drug
- Status
- Marketed; latest approval 2011
- Kind
- Small molecule
- Brand name
- Zyloprim
- First approved
- 7 October 1966 (CH)
- Approvals on record
- 20 in 5 regions
- Holder of the most recent approval
- Casper Pharma; 10 holders in all
- Registered trials
- 113, 14 stopped early
- Disease areas
- Inherited and neonatal; Nutrition and metabolism; Cancer; Immune system; Blood and lymph; Heart and blood vessels
US protection
No US protection of its own is listed.
The FDA registers list no drug-substance patent or exclusivity of its own that counts for this drug.
Ironwood Pharmaceuticals holds a later exclusivity on its own new formulation or combination product, ending 2032; it does not protect the original drug.
This is the US only.
Target
| Gene | Protein | UniProt |
|---|---|---|
| XDH | Xanthine dehydrogenase/oxidase [Includes: Xanthine dehydrogenase | P47989 |
Registered trials
| Phase | Trials | Completed | Active | Stopped early |
|---|---|---|---|---|
| Phase not stated | 16 | 9 | 1 | 3 |
| Phase 1 | 21 | 18 | 1 | 2 |
| Phase 2 | 40 | 29 | 2 | 6 |
| Phase 3 | 17 | 12 | 1 | 1 |
| Phase 4 | 19 | 14 | 0 | 2 |
| All trials | 113 |