title: Unlicensed use of metformin in children and adolescents in the UK.
abstract: OBJECTIVE
  Metformin is the most commonly prescribed oral anti-diabetic drug in young people. It is also prescribed for polycystic ovarian syndrome (PCOS) and obesity treatment in adults in an unlicensed fashion. Little is known as to the extent metformin has been used in young people. We investigated the use of metformin in children and adolescents aged 0-18 years in the UK.
  
  
  METHODS
  Population-based prescribing data were obtained from the UK IMS Disease Analyzer between January 2000 and December 2010.
  
  
  RESULTS
  A total of 2674 metformin prescriptions were issued to 337 patients (80% female) between 2000 and 2010. The prevalence of metformin prescribing increased from 0.03 per 1000 person-years [95% confidence interval (CI) 0.02, 0.05] to 0.16 per 1000 person-years (95% CI 0.12, 0.20) (P= 0.001). There was a steady increase in metformin prescribing in girls aged 16-18 years. There were 290 metformin treated patients (81% female; n= 235) who had at least one diagnosis of diabetes, PCOS or obesity. Among these patients, PCOS was the most common indication for metformin prescribing in girls (n= 120) followed by diabetes. There were 22 patients (7.6%) who received metformin for obesity treatment only.
  
  
  CONCLUSIONS
  Prescribing of metformin increased between 2000 and 2010, in particular amongst girls aged 16-18 years. The main indication for metformin prescribing was PCOS. At present, metformin is not licensed for PCOS and obesity treatment in adults or children. As there is a steady increase in the prescribing of metformin in young people, further studies are required to investigate the efficacy and safety of these prescriptions.
authors.affiliation: Centre for Paediatric Pharmacy Research, The School of Pharmacy, University of London, London, UK. yingfen.hsia@pharmacy.ac.uk
authors.forename: Yingfen
authors.initials: Y
authors.lastname: Hsia
authors.forename: Dalia
authors.initials: D
authors.lastname: Dawoud
authors.forename: Alastair G
authors.initials: AG
authors.lastname: Sutcliffe
authors.forename: Russell M
authors.initials: RM
authors.lastname: Viner
authors.forename: Sanjay
authors.initials: S
authors.lastname: Kinra
authors.forename: Ian C K
authors.initials: IC
authors.lastname: Wong
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000188:drug therapy*; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D004363:Drug Utilization / Q000331:legislation & jurisprudence / Q000639:trends; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007223:Infant; D007880:Legislation, Drug; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D009765:Obesity / Q000188:drug therapy*; D056687:Off-Label Use; D011085:Polycystic Ovary Syndrome / Q000188:drug therapy*; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data / Q000639:trends*; D012189:Retrospective Studies; D006113:United Kingdom
chemical_list: D007004:Hypoglycemic Agents; D008687:Metformin