Radafaxine Structural Formulae.png
Clinical data
Other names(S,S)-Hydroxybupropion; (2S,3S)-Hydroxybupropion; GW-353,162
Routes of
ATC code
  • none
  • (+)-(2S,3S)-2-(3-chlorophenyl)-3,5,5-trimethylmorpholin-2-ol
CAS Number
PubChem CID
Chemical and physical data
Molar mass255.74 g·mol−1
3D model (JSmol)
  • Clc1cccc(c1)[C@]2(O)OCC(N[C@H]2C)(C)C
  • InChI=1S/C13H18ClNO2/c1-9-13(16,17-8-12(2,3)15-9)10-5-4-6-11(14)7-10/h4-7,9,15-16H,8H2,1-3H3/t9-,13+/m0/s1 checkY
 ☒NcheckY (what is this?)  (verify)

Radafaxine (developmental code name GW-353,162), also known as (2S,3S)-hydroxybupropion or (S,S)-hydroxybupropion,[1] is a norepinephrine–dopamine reuptake inhibitor (NDRI) which was under development by GlaxoSmithKline in the 2000s for a variety of different indications but was never marketed.[2] These uses included treatment of restless legs syndrome, major depressive disorder, bipolar disorder, neuropathic pain, fibromyalgia, and obesity.[2] Regulatory filing was planned for 2007,[3] but development was discontinued in 2006 due to "poor test results".[4]



Radafaxine is described as a norepinephrine–dopamine reuptake inhibitor (NDRI). In contrast to bupropion, it appears to have a higher potency on inhibition of norepinephrine reuptake than on dopamine reuptake. Radafaxine has about 70% of the efficacy of bupropion in blocking dopamine reuptake, and 392% of efficacy in blocking norepinephrine reuptake, making it fairly selective for inhibiting the reuptake of norepinephrine over dopamine.[5][6] This, according to GlaxoSmithKline, may account for the increased effect of radafaxine on pain and fatigue.[7] At least one study suggests that radafaxine has a low abuse potential similar to bupropion.[8]


Radafaxine is a potent metabolite of bupropion, the compound in GlaxoSmithKline's Wellbutrin. More specifically, "hydroxybupropion" is an analogue of bupropion, and radafaxine is an isolated isomer ((2S,3S)-) of hydroxybupropion.[9] Therefore, radafaxine builds on at least some of the properties of bupropion in humans.[3] Another analogue of bupropion, manifaxine (GW-320,659), was derived from radafxine and was also studied.[10]

See also


  1. ^ Carroll FI, Blough BE, Mascarella SW, Navarro HA, Lukas RJ, Damaj MI (2014). "Bupropion and bupropion analogs as treatments for CNS disorders". Emerging Targets & Therapeutics in the Treatment of Psychostimulant Abuse. Adv Pharmacol. Advances in Pharmacology. Vol. 69. pp. 177–216. doi:10.1016/B978-0-12-420118-7.00005-6. ISBN 9780124201187. PMID 24484978.
  2. ^ a b "Radafaxine - AdisInsight".
  3. ^ a b "Reviews Novel Therapeutics For CNS Disorders And Confirms Strong Pipeline Momentum". BioSpace. 23 November 2004. Archived from the original on 2007-09-28.
  4. ^ Kollewe J (27 July 2006). "GSK breakthrough on bird flu vaccine". Independent.co.uk. Archived from the original on 2007-10-01.
  5. ^ Xu H, Loboz KK, Gross AS, McLachlan AJ (March 2007). "Stereoselective analysis of hydroxybupropion and application to drug interaction studies". Chirality. 19 (3): 163–70. doi:10.1002/chir.20356. PMID 17167747.
  6. ^ Bondarev ML, Bondareva TS, Young R, Glennon RA (August 2003). "Behavioral and biochemical investigations of bupropion metabolites". European Journal of Pharmacology. 474 (1): 85–93. doi:10.1016/S0014-2999(03)02010-7. PMID 12909199.
  7. ^ Burch D. "Neurosciences Development Portfolio" (PDF). Archived from the original (PDF) on 2007-09-28.
  8. ^ Volkow ND, Wang GJ, Fowler JS, Learned-Coughlin S, Yang J, Logan J, et al. (March 2005). "The slow and long-lasting blockade of dopamine transporters in human brain induced by the new antidepressant drug radafaxine predict poor reinforcing effects". Biological Psychiatry. 57 (6): 640–6. doi:10.1016/j.biopsych.2004.12.007. PMID 15780851. S2CID 13313064.
  9. ^ Radafaxine at the US National Library of Medicine Medical Subject Headings (MeSH)
  10. ^ "Manifaxine - AdisInsight".