title: Weight change associated with antiepileptic drugs.
abstract: OBJECTIVE
  To investigate antiepileptic drug (AED)-related weight changes in patients with epilepsy through a retrospective observational study.
  
  
  METHODS
  We analysed the anonymised electronic primary care records of 1.1 million adult patients in Wales. We included patients aged 18 years and over with a diagnosis of epilepsy, whose body weight had been measured up to 12 months before starting, and between 3 and 12 months after starting, one of five AEDs. We calculated the weight difference after starting the AED for each patient.
  
  
  RESULTS
  1423 patients were identified in total. The mean difference between body weight after and before starting each AED (together with 95% CI and p values for no difference) were: carbamazepine (CBZ) 0.43 (-0.19 to 1.05) p=0.17; lamotrigine (LTG) 0.31 (-0.38 to 1.00) p=0.38; levetiracetam (LEV) 1.00 (0.16 to 1.84) p=0.02; sodium valproate (VPA) 0.74 (0.10 to 1.38) p=0.02; topiramate (TPM) -2.30 (-4.27 to -0.33) p=0.02.
  
  
  CONCLUSIONS
  LEV and VPA were associated with significant weight gain, TPM was associated with significant weight loss, and LTG and CBZ were not associated with significant weight change.
authors.affiliation: Neurology and Molecular Neuroscience Research Group, Institute of Life Science, College of Medicine, Swansea University, 3rd Floor, ILS, Swansea SA2 8PP, UK. w.o.pickrell@swansea.ac.uk
authors.forename: William Owen
authors.initials: WO
authors.lastname: Pickrell
authors.forename: Arron S
authors.initials: AS
authors.lastname: Lacey
authors.forename: Rhys H
authors.initials: RH
authors.lastname: Thomas
authors.forename: Philip E M
authors.initials: PE
authors.lastname: Smith
authors.forename: Mark I
authors.initials: MI
authors.lastname: Rees
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000927:Anticonvulsants / Q000009:adverse effects* / Q000627:therapeutic use; D001835:Body Weight / Q000187:drug effects*; D015897:Comorbidity; D057286:Electronic Health Records; D004827:Epilepsy / Q000150:complications* / Q000188:drug therapy / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care; D011446:Prospective Studies; D014852:Wales / Q000453:epidemiology; D015430:Weight Gain / Q000187:drug effects; D015431:Weight Loss / Q000187:drug effects; D055815:Young Adult
chemical_list: D000927:Anticonvulsants