title: Increase in the threshold of pain and touch sensation in the human face with clonidine plus 30% nitrous oxide.
abstract: OBJECTIVE
  This study was undertaken to assess the effects of clonidine combined with 30% nitrous oxide on tactile and pain sensations in the human face.
  
  
  METHODS
  Thirty-three subjects were involved in the study. The subjects were divided into 4 groups: 100% oxygen with placebo; 30% N2O with placebo; 100% oxygen with clonidine (0.075 mg), and 30% N2O with clonidine. Three tests for the threshold of pain sensation and tactile sensation were made at 60 minutes before and 0, 15, and 30 minutes during N2O or O2 inhalation.
  
  
  RESULTS
  (1) The N2O with clonidine significantly increased the threshold of pain and tactile sensation in comparison with the other 3 treatments. (2) In terms of pain sensation, both N2O and clonidine showed significant increases in threshold of pain in comparison with the control values.
  
  
  CONCLUSIONS
  These results indicate that the analgesic effects of 30% nitrous oxide are enhanced when use of the gas is combined with prior clonidine administration.
authors: Department of Dental Anesthesiology, Kyushu Dental College, Kokurakita, Kitakyushu, Japan.
authors: S
authors: S
authors: Siiba
authors: O
authors: O
authors: Nakanishi
authors: T
authors: T
authors: Ishikawa
authors: T
authors: T
authors: Hirakawa
authors: H
authors: H
authors: Kawahara
authors: Y
authors: Y
authors: Imamura
mesh_terms: D000328:Adult; D000766:Anesthesia, Dental; D019162:Anesthetics, Combined / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D003000:Clonidine / Q000494:pharmacology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D009609:Nitrous Oxide / Q000494:pharmacology; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects; D012684:Sensory Thresholds / Q000187:drug effects*; D018709:Statistics, Nonparametric; D014110:Touch / Q000187:drug effects
chemical_list: D019162:Anesthetics, Combined; D009609:Nitrous Oxide; D003000:Clonidine