Clinical data
Trade namesTandearil, Tanderil
AHFS/Drugs.comInternational Drug Names
ATC code
Legal status
Legal status
  • AU: Withdrawn
  • UK: Withdrawn
  • US: Withdrawn
  • (RS)-4-butyl-1-(4-hydroxyphenyl)-2-phenylpyrazolidine-3,5-dione
CAS Number
PubChem CID
CompTox Dashboard (EPA)
ECHA InfoCard100.004.489 Edit this at Wikidata
Chemical and physical data
Molar mass324.380 g·mol−1
3D model (JSmol)
ChiralityRacemic mixture
  • O=C2N(c1ccc(O)cc1)N(C(=O)C2CCCC)c3ccccc3.O
  • InChI=1S/C19H20N2O3.H2O/c1-2-3-9-17-18(23)20(14-7-5-4-6-8-14)21(19(17)24)15-10-12-16(22)13-11-15;/h4-8,10-13,17,22H,2-3,9H2,1H3;1H2 checkY
 ☒NcheckY (what is this?)  (verify)

Oxyphenbutazone is a nonsteroidal anti-inflammatory drug (NSAID).[1] It is a metabolite of phenylbutazone.[2]

It was withdrawn from markets worldwide in mid-1980s due to bone marrow suppression and the risk of Stevens–Johnson syndrome.[3][4]

In Scrabble, the word "oxyphenbutazone" is the present highest scoring word resulting in 1,780 points based on the NASPA word list of 2006.[5]


  1. ^ Singh N, Jabeen T, Somvanshi RK, Sharma S, Dey S, Singh TP (November 2004). "Phospholipase A2 as a target protein for nonsteroidal anti-inflammatory drugs (NSAIDS): crystal structure of the complex formed between phospholipase A2 and oxyphenbutazone at 1.6 A resolution". Biochemistry. 43 (46): 14577–83. doi:10.1021/bi0483561. PMID 15544328.
  2. ^ Matthews NS, Peck KE, Taylor TS, Mealey KL (May 2001). "Pharmacokinetics of phenylbutazone and its metabolite oxyphenbutazone in miniature donkeys". American Journal of Veterinary Research. 62 (5): 673–5. doi:10.2460/ajvr.2001.62.673. PMID 11341383.
  3. ^ Fung M, Thornton A, Mybeck K, Wu JH, Hornbuckle K, Muniz E (January 2001). "Evaluation of the Characteristics of Safety Withdrawal of Prescription Drugs from Worldwide Pharmaceutical Markets-1960 to 1999". Therapeutic Innovation & Regulatory Science. 35 (1): 293–317. doi:10.1177/009286150103500134. S2CID 73036562.
  4. ^ Biron P (May 1986). "Withdrawal of oxyphenbutazone: what about phenylbutazone?". CMAJ. 134 (10): 1119–20. PMC 1491052. PMID 3697857.
  5. ^ Wood D (22 May 2008). "Record for the Highest Scoring Scrabble Move". Scrabulizer. Archived from the original on 11 May 2023.