title: Leflunomide discontinuation in rheumatoid arthritis and influence of associated disease-modifying anti-rheumatic drugs: a survival analysis.
abstract: OBJECTIVE
  The aims of this study were to describe the rate of leflunomide discontinuation in rheumatoid arthritis (RA) patients, in standard clinical practice, and to analyse which factors could influence this rate, paying particular attention to the concomitant treatment with other disease-modifying anti-rheumatic drugs (DMARDs).
  
  
  METHODS
  We selected RA patients, diagnosed according to the 1987 American College of Rheumatology (ACR) criteria, attending the rheumatology outpatient clinic of the San Carlos Clinical Hospital (Madrid, Spain), who had started treatment with leflunomide between 1 January 2006 and 1 January 2011. Clinical records were examined until withdrawal of the drug, loss of follow-up, or 1 October 2011. Kaplan-Meier curves were set to account for leflunomide withdrawal. Cox bivariate and multivariate regression models were conducted to examine risk factors for leflunomide discontinuation.
  
  
  RESULTS
  The incident rate (IR) for leflunomide discontinuation, regardless of the cause, was 27 per 100 patient-years [95% confidence interval (CI) 22-31]. We observed, in both the bivariate and multivariate regression analysis, that those aged > 75 years at the start of the leflunomide treatment and undergoing concurrent treatment with methotrexate (MTX) and/or hydroxychloroquine (HC) had a significantly higher risk of leflunomide discontinuation.
  
  
  CONCLUSIONS
  An older age at the start of the treatment with leflunomide, or concomitant treatment with MTX and/or HC, could be associated with a higher risk of leflunomide discontinuation, regardless of the cause. Therefore, when taking MTX or HC, patients receiving leflunomide should be closely monitored early to detect the occurrence of adverse reactions, and hence prevent their aggravation.
authors.affiliation: Department of Rheumatology and Health Research Institute, San Carlos Clinical Hospital (IDISSC) , Madrid , Spain.
authors.forename: L
authors.initials: L
authors.lastname: Rodriguez-Rodriguez
authors.forename: J A
authors.initials: JA
authors.lastname: Jover-Jover
authors.forename: O
authors.initials: O
authors.lastname: Fontsere
authors.forename: R C
authors.initials: RC
authors.lastname: Peña-Blanco
authors.forename: L
authors.initials: L
authors.lastname: León
authors.forename: B
authors.initials: B
authors.lastname: Fernández-Gutierrez
authors.forename: L
authors.initials: L
authors.lastname: Abásolo
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000401:mortality*; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006886:Hydroxychloroquine / Q000627:therapeutic use; D007555:Isoxazoles / Q000009:adverse effects / Q000627:therapeutic use*; D053208:Kaplan-Meier Estimate; D000077339:Leflunomide; D008137:Longitudinal Studies; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D028761:Withholding Treatment / Q000639:trends*
chemical_list: D018501:Antirheumatic Agents; D007555:Isoxazoles; D006886:Hydroxychloroquine; D000077339:Leflunomide; D008727:Methotrexate