title: Prevalence of methotrexate intolerance in rheumatoid arthritis and psoriatic arthritis.
abstract: BACKGROUND
  The aim of this study was to determine the prevalence of gastrointestinal and behavioural symptoms occurring before (anticipatory/associative) and after methotrexate (MTX) administration, termed MTX intolerance, in rheumatoid (RA) and psoriatic arthritis (PsA).
  
  
  METHODS
  Methotrexate Intolerance Severity Score (MISS), previously validated in juvenile idiopathic arthritis patients, was used to determine MTX intolerance prevalence in 291 RA/PsA patients. The MISS consisted of four domains: abdominal pain, nausea, vomiting and behavioural symptoms, occurring upon, prior to (anticipatory) and when thinking of MTX (associative). MTX intolerance was defined as ≥6 on the MISS with ≥1 point on anticipatory and/or associative and/or behavioural items.
  
  
  RESULTS
  A total of 123 patients (42.3%) experienced at least one gastrointestinal adverse effect. The prevalence of MTX intolerance was 11%. MTX intolerance prevalence was higher in patients on parenteral (20.6%) than on oral MTX (6.2%) (p < 0.001).
  
  
  CONCLUSIONS
  Besides well-known gastrointestinal symptoms after MTX, RA and PsA patients experienced these symptoms also before MTX intake. RA and PsA patients on MTX should be closely monitored with the MISS for early detection of MTX intolerance, in order to intervene timely and avoid discontinuation of an effective treatment.
authors.forename: Maja Bulatović
authors.initials: MB
authors.lastname: Ćalasan
authors.forename: Oscar F C
authors.initials: OF
authors.lastname: van den Bosch
authors.forename: Marjonne C W
authors.initials: MC
authors.lastname: Creemers
authors.forename: Martijn
authors.initials: M
authors.lastname: Custers
authors.forename: Antonius H M
authors.initials: AH
authors.lastname: Heurkens
authors.forename: Jan Maarten
authors.initials: JM
authors.lastname: van Woerkom
authors.forename: Nico M
authors.initials: NM
authors.lastname: Wulffraat
mesh_terms: D000893:Anti-Inflammatory Agents / Q000009:adverse effects*; D015535:Arthritis, Psoriatic / Q000188:drug therapy*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D003430:Cross-Sectional Studies; D005260:Female; D005767:Gastrointestinal Diseases / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D008297:Male; D008727:Methotrexate / Q000009:adverse effects*; D008875:Middle Aged; D015995:Prevalence
chemical_list: D000893:Anti-Inflammatory Agents; D008727:Methotrexate