title: Can daily repeated doses of orally administered glucose induce tolerance when given for neonatal pain relief?
abstract: OBJECTIVE
  Orally administered sweet solutions have a pain-relieving effect during painful procedures in newborn infants. The underlying mechanism is not fully understood, but, from the results of animal research, an opioid-like mechanism is often suggested. The aim of this study was to determine whether repeated doses of orally administered glucose would cause tolerance to glucose.
  
  
  METHODS
  Fifty-seven healthy, full-term infants were recruited on the day of birth to receive three daily doses of either 1 ml 30% glucose or sterile water for 3-5 d, after which routine blood samples were collected by heel-lance. All infants received 1 ml 30% glucose before the heel-lance was carried out. Crying time, Premature Infant Pain Profile scores and changes in heart rate were used as pain measures.
  
  
  RESULTS
  No differences were found between the groups, either in demographic data or in the outcome variables.
  
  
  CONCLUSIONS
  No tolerance was observed under the conditions prevailing in this study. However, we cannot rule out an endogenous opioid mechanism. What is clinically important is that repeated doses of glucose do not decrease the pain-relieving effect.
authors.affiliation: Department of Paediatrics, Orebro University Hospital, SE-701 85 Orebro, Sweden. mats.eriksson@orebroll.se
authors.forename: Mats
authors.initials: M
authors.lastname: Eriksson
authors.forename: O
authors.initials: O
authors.lastname: Finnström
mesh_terms: D000596:Amino Acids / Q000187:drug effects*; D002857:Chromium; D003448:Crying; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005947:Glucose / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007231:Infant, Newborn; D009539:Nicotinic Acids; D010146:Pain / Q000188:drug therapy*; D010147:Pain Measurement / Q000379:methods*; D012996:Solutions
chemical_list: D000596:Amino Acids; D009539:Nicotinic Acids; D012996:Solutions; C015240:glucose tolerance factor; D002857:Chromium; D005947:Glucose