title: The duration and course of opioid therapy in patients with chronic non-malignant pain.
abstract: BACKGROUND
  Prescription databases provide the opportunity for investigating opioid treatment and co-medication within large populations. So far, few studies have investigated the duration of opioid therapy, and large differences in discontinuation rates have been reported.
  
  
  METHODS
  Data from the Norwegian Prescription Database were used to follow the study population of all adult persistent opioid users with non-malignant pain in Norway in 2005 (n = 44,867) for 6 years. Persistent opioid use was defined as being dispensed ≥ 180 defined daily doses (DDD) or 4500 mg oral morphine equivalents (OMEQ) during a 365-day period. The study population was stratified according to previous opioid use into new persistent opioid users, without previous persistent opioid use, and previous low-dose or previous high-dose persistent opioid users, having earlier persistent opioid use and received less or more than 120 mg OMEQ/day in 2005, respectively.
  
  
  RESULTS
  Twenty-seven percent of new, 59% of previous low-dose, and 55% of previous high-dose users met the criteria of persistent use of opioids each year. Exactly, 22%, 11%, and 3% increased their cumulative yearly opioid dose by 200% or more during the study period. With 80% still being regular users of either drugs, 6 years later, long-term persistent opioid users were more likely to continue concomitant use of benzodiazepines or z-hypnotics than other users,
  
  
  CONCLUSIONS
  The findings confirm high discontinuation rates in patients receiving opioids for chronic non-malignant pain. However, a clinically significant number of patients increase their doses over 6 years and many patients combine long-term opioid treatment with benzodiazepines and z-hypnotics.
authors.affiliation: Department of Circulation and Medical Imaging, Pain and Palliation Research Group, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.|National Competence Centre for Complex Symptom Disorders, St. Olav's University Hospital, Trondheim, Norway.
authors.forename: A
authors.initials: A
authors.lastname: Mellbye
authors.affiliation: Department of Pharmacoepidemiology, Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Ø
authors.initials: Ø
authors.lastname: Karlstad
authors.affiliation: Norwegian Centre for Addiction Research, University of Oslo, Oslo, Norway.|Department of Pharmacoepidemiology, Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: S
authors.initials: S
authors.lastname: Skurtveit
authors.affiliation: Department of Circulation and Medical Imaging, Pain and Palliation Research Group, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.|National Competence Centre for Complex Symptom Disorders, St. Olav's University Hospital, Trondheim, Norway.
authors.forename: P C
authors.initials: PC
authors.lastname: Borchgrevink
authors.affiliation: Department of Circulation and Medical Imaging, Pain and Palliation Research Group, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.|National Competence Centre for Complex Symptom Disorders, St. Olav's University Hospital, Trondheim, Norway.|Centre of Palliative Medicine, Akershus University Hospital, Oslo, Norway.
authors.forename: O M S
authors.initials: OM
authors.lastname: Fredheim
mesh_terms: D000328:Adult; D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D001569:Benzodiazepines / Q000627:therapeutic use; D059350:Chronic Pain / Q000188:drug therapy* / Q000209:etiology; D015331:Cohort Studies; D016208:Databases, Factual; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D004363:Drug Utilization; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D055553:Prescription Drugs; D011446:Prospective Studies
chemical_list: D000701:Analgesics, Opioid; D006993:Hypnotics and Sedatives; D055553:Prescription Drugs; D001569:Benzodiazepines