title: Does intrathecal morphine in the treatment of cancer pain induce the development of tolerance?
abstract: OBJECTIVE
  This retrospective study was designed to investigate whether chronic lumbar intrathecal administration of morphine leads to the development of opioid tolerance in patients suffering from intractable cancer pain.
  
  
  METHODS
  Between 1978 and 1995, 159 patients with refractory cancer pain were treated with intrathecal morphine in our Multidisciplinary Pain Center. The treatment consisted of preservative-free morphine administered through an access port as a single bolus. In this series of patients (n = 159), the daily doses of intrathecal morphine were determined as a function of duration of follow-up.
  
  
  RESULTS
  The mean follow-up period was 95 days (range, 5-909 d), the mean starting daily dose of intrathecal morphine was 2.69 mg (range, 1-7.5 mg), and the mean terminal dose was 7.82 mg (range, 1-80 mg). The results demonstrated that only a moderate increase in daily dose of intrathecal morphine was required during the course of treatment (a two- to threefold increase for a 3-mo period). Furthermore, the dose increment was similar for patients followed up for more or less than 60 days. This increase did not result in any central opioid-related side effects, and the pain was managed satisfactorily.
  
  
  CONCLUSIONS
  The requirement for a moderate increase in intrathecal opioid doses reflects the development of tolerance but did not limit the patients' ability to obtain adequate analgesia during the course of their painful disease.
authors.affiliation: Department of Neurosurgery, Faculty of Pharmaceutic Sciences, Paul Sabatier University, Toulouse, France.
authors.forename: B
authors.initials: B
authors.lastname: Sallerin-Caute
authors.forename: Y
authors.initials: Y
authors.lastname: Lazorthes
authors.forename: O
authors.initials: O
authors.lastname: Deguine
authors.forename: B
authors.initials: B
authors.lastname: Francés
authors.forename: J C
authors.initials: JC
authors.lastname: Verdié
authors.forename: J P
authors.initials: JP
authors.lastname: Charlet
authors.forename: R
authors.initials: R
authors.lastname: Bastide
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007278:Injections, Spinal; D008161:Lumbosacral Region; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage* / Q000627:therapeutic use; D009369:Neoplasms / Q000188:drug therapy*; D010148:Intractable Pain / Q000188:drug therapy*; D010166:Palliative Care; D012189:Retrospective Studies
chemical_list: D000701:Analgesics, Opioid; D009020:Morphine