Clinical data
Other namesCO-134444; Co 134444; V-134444; 3β-Hydroxy-21-(1H-imidazol-1-yl)-3α-(methoxymethyl)-5α-pregnan-20-one
  • 1-[(3R,5S,8R,9S,10S,13S,14S,17S)-3-hydroxy-3-(methoxymethyl)-10,13-dimethyl-1,2,4,5,6,7,8,9,11,12,14,15,16,17-tetradecahydrocyclopenta[a]phenanthren-17-yl]-2-imidazol-1-ylethanone
CAS Number
PubChem CID
Chemical and physical data
Molar mass428.617 g·mol−1
3D model (JSmol)
  • C[C@]12CC[C@@](C[C@@H]1CC[C@@H]3[C@@H]2CC[C@]4([C@H]3CC[C@@H]4C(=O)CN5C=CN=C5)C)(COC)O
  • InChI=1S/C26H40N2O3/c1-24-10-11-26(30,16-31-3)14-18(24)4-5-19-20-6-7-22(25(20,2)9-8-21(19)24)23(29)15-28-13-12-27-17-28/h12-13,17-22,30H,4-11,14-16H2,1-3H3/t18-,19-,20-,21-,22+,24-,25-,26+/m0/s1

Posovolone (developmental code name Co 134444) is a synthetic neurosteroid which was under development as a sedative/hypnotic medication for the treatment of insomnia.[1][2] [3][4] It is orally active and acts as a GABAA receptor positive allosteric modulator.[1][5][2] In animals, posovolone shows anticonvulsant, anxiolytic-like, ataxic, and sleep-promoting effects and appeared to produce effects similar to those of pregnanolone.[2][6] Development of the agent was started by 1999 and appears to have been discontinued by 2007.[1][6] In 2021, an INNTooltip International Nonproprietary Name was registered for posovolone with the descriptor of "antidepressant".[5] Posovolone was originally developed by Purdue Pharma.[1]

See also


  1. ^ a b c d "CO 134444 - AdisInsight".
  2. ^ a b c Vanover KE, Hogenkamp DJ, Lan NC, Gee KW, Carter RB (May 2001). "Behavioral characterization of Co 134444 (3alpha-hydroxy-21-(1'-imidazolyl)-3beta-methoxymethyl-5alpha- pregnan-20-one), a novel sedative-hypnotic neuroactive steroid". Psychopharmacology (Berl). 155 (3): 285–91. doi:10.1007/s002130100695. PMID 11432691. S2CID 44353086.
  3. ^ Hamilton NM (August 2002). "Interaction of steroids with the GABA(A) receptor". Curr Top Med Chem. 2 (8): 887–902. doi:10.2174/1568026023393570. PMID 12171578.
  4. ^ Belelli D, Hogenkamp D, Gee KW, Lambert JJ (May 2020). "Realising the therapeutic potential of neuroactive steroid modulators of the GABAA receptor". Neurobiol Stress. 12: 100207. doi:10.1016/j.ynstr.2019.100207. PMC 7231973. PMID 32435660.
  5. ^ a b https://cdn.who.int/media/docs/default-source/international-nonproprietary-names-(inn)/pl126.pdf#page=137[bare URL PDF]
  6. ^ a b Vanover KE, Edgar DM, Seidel WF, Hogenkamp DJ, Fick DB, Lan NC, Gee KW, Carter RB (December 1999). "Response-rate suppression in operant paradigm as predictor of soporific potency in rats and identification of three novel sedative-hypnotic neuroactive steroids". J Pharmacol Exp Ther. 291 (3): 1317–23. PMID 10565857.