title: Effect of valdecoxib pretreatment on pain and secondary hyperalgesia: a randomized controlled trial in healthy volunteers [ISRCTN05282752, NCT00260325].
abstract: BACKGROUND
  Induction of the COX-2 isoenzyme appears to play a major role in the genesis of central sensitization after nociceptive stimulation. This study aimed to investigate the efficacy of a single, oral dose of the specific COX-2 inhibitor-valdecoxib in attenuating the central sensitization - induced secondary hyperalgesia in a heat/capsaicin pain model in healthy volunteers.
  
  
  METHODS
  The study was a randomized, double blind, placebo controlled, crossover, single dose efficacy trial using 20 healthy volunteers. Two hours following placebo or 40 mg, PO valdecoxib, participants underwent skin sensitization with heat/capsaicin, as well as supra-threshold pain and re-kindling measurements according to an established, validated pain model. Subjects rated pain intensity and unpleasantness on a visual analog scale and the area of secondary hyperalgesia was serially mapped.
  
  
  RESULTS
  The area of secondary hyperalgesia produced after 40 mg of valdecoxib was no different than that after placebo. Furthermore, there were no significantly relevant differences when volunteers were treated with valdecoxib or placebo in relation to either cold- or hot pain threshold or the intensity of pain after supra-threshold, thermal pain stimulation.
  
  
  CONCLUSIONS
  We demonstrated that a single, oral dose of valdecoxib when does not attenuate secondary hyperalgesia induced by heat/capsaicin in a cutaneous sensitization pain model in healthy volunteers.
authors.affiliation: Department of Anesthesiology, Pennsylvania State College of Medicine and Milton S, Hershey Medical Center, Hershey, Pennsylvania, USA. dburns@psu.edu
authors.forename: David
authors.initials: D
authors.lastname: Burns
authors.forename: Lindsay
authors.initials: L
authors.lastname: Hill
authors.forename: Michael
authors.initials: M
authors.lastname: Essandoh
authors.forename: Tomasz M
authors.initials: TM
authors.lastname: Jarzembowski
authors.forename: H Gregg
authors.initials: HG
authors.lastname: Schuler
authors.forename: Piotr K
authors.initials: PK
authors.lastname: Janicki