title: Switching from high doses of pure μ-opioid agonists to transdermal buprenorphine in patients with cancer: a feasibility study.
abstract: BACKGROUND
  Several myths on buprenorphine's pharmacology exist: possible analgesic ceiling effect, feasibility of combination with other opioid agonists, and the reversibility of side effects. Aim to evaluate: 1) if cancer patients receiving high doses of pure agonists could obtain adequate pain relief after switching to transdermal (TD) buprenorphine and 2) whether the numbers of breakthrough pain episodes after switching increased and whether they could be treated with the same doses of pure agonist as before switching.
  
  
  METHODS
  The prospective open multicenter study included outpatients with moderate-to-severe cancer pain satisfactorily controlled.
  
  
  METHODS
  Patients were switched from the usual pure agonist to TD buprenorphine and were titrated to a stable dose. The assessments were: 1) daily self-assessment of pain intensity, numbers of rescue medications, and pain interference with sleep; 2) brief pain inventory; 3) pain relief and pain intensity; 4) quality of life; and 5) adverse events and symptoms.
  
  
  RESULTS
  Eighteen patients receiving 150-516 mg of morphine/day were included. The buprenorphine dose at the end of the study varied between 52.5 and 140 μg/h. No difference in pain before and after switching was shown. The level of rescue doses was maintained. The patches were well tolerated. A significant decrease in fatigue and an increase in global health status were seen after the switch.
  
  
  CONCLUSIONS
  It is feasible to switch cancer patients from high doses of pure μ-opioid agonists to TD buprenorphine without eliciting any antagonist effects, but the dose conversion factor is individual and the switching process should be tailored for the individual patient.
authors.affiliation: Consultant, Department of Palliative Care, Herning, Denmark; Department of Palliative Care, Uddevalla, Sweden.
authors.forename: Lena
authors.initials: L
authors.lastname: Lundorff
authors.affiliation: Professor, Consultant, Section of Palliative Medicine, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Per
authors.initials: P
authors.lastname: Sjøgren
authors.affiliation: Consultant, Palliative and Pain Clinic, Holbæk Sygehus, Denmark.
authors.forename: Ole Bo
authors.initials: OB
authors.lastname: Hansen
authors.affiliation: Consultant, Multidisciplinary Pain Centre, Køge Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Torsten
authors.initials: T
authors.lastname: Jonsson
authors.affiliation: Multidisciplinary Pain Centre, Rigshospitalet, Denmark.
authors.forename: Per Rotbøll
authors.initials: PR
authors.lastname: Nielsen
authors.affiliation: Professor, Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Lona
authors.initials: L
authors.lastname: Christrup
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000009:adverse effects; D000704:Analysis of Variance; D059390:Breakthrough Pain / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology; D002047:Buprenorphine / Q000008:administration & dosage* / Q000009:adverse effects; D059350:Chronic Pain / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism; D003718:Denmark; D057915:Drug Substitution; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications*; D016017:Odds Ratio; D010147:Pain Measurement; D011446:Prospective Studies; D011788:Quality of Life; D017450:Receptors, Opioid, mu / Q000819:agonists* / Q000378:metabolism; D011795:Surveys and Questionnaires; D057968:Transdermal Patch; D016896:Treatment Outcome
chemical_list: D000701:Analgesics, Opioid; D017450:Receptors, Opioid, mu; D002047:Buprenorphine