title: Combination and switching of stimulants in children and adolescents with attention deficit/hyperactivity disorder in quebec.
abstract: OBJECTIVE
  To assess the one-year period prevalence of stimulant combination therapy and switching in children/ adolescents with attention deficit/hyperactivity disorder (ADHD) in Quebec, Canada.
  
  
  METHODS
  Patients aged 6-17 years, with at least two ADHD diagnosis codes documented in different visits and at least 30 days' supply of a stimulant during their most recent one-year observation period were selected from the Regie de l'assurance maladie du Quebec database (03/2007-02/2012). Combination therapy was defined as at least 30 consecutive days of concomitant use of multiple stimulants with different active moieties, or use of a stimulant and another psychotropic medication. Therapy switching was defined as a prescription claim for a new psychotropic medication less than 30 days before or after the end of supply of a stimulant. The one-year period prevalence of therapy combination and switching was calculated.
  
  
  RESULTS
  The one-year period prevalence of combination therapy and switching among 9,431 children and adolescents with ADHD treated with stimulants was 19.8% and 18.7%, respectively. The most frequent combination categories were atypical antipsychotics (AAP: 10.8%), atomoxetine (ATX: 5.5%) and clonidine (5.3%). The most frequent switched-to categories were other stimulants (7.9%), AAP (5.5%) and ATX (4.7%).
  
  
  CONCLUSIONS
  Approximately one in five children/adolescents with ADHD on a stimulant experienced combination therapy or therapy switching; however, the majority of the medications used in combination or switching were not label-indicated for the treatment of ADHD in Canada. These results highlight the need for further research to evaluate the risk-benefit of stimulant combination and switching in children and adolescents with ADHD.
authors.affiliation: Université de Montreal, Montreal, Quebec ; Sainte-Justine Research Center, Montreal, Quebec.
authors.forename: Leila
authors.initials: L
authors.lastname: Ben Amor
authors.affiliation: Shire Pharmaceuticals Inc., Wayne, Pennsylvania, USA.
authors.forename: Vanja
authors.initials: V
authors.lastname: Sikirica
authors.affiliation: Groupe d'analyse, Montreal, Quebec.
authors.forename: Martin
authors.initials: M
authors.lastname: Cloutier
authors.affiliation: Université de Montreal, Montreal, Quebec.
authors.forename: Jean
authors.initials: J
authors.lastname: Lachaine
authors.affiliation: Shire Pharmaceuticals Inc., Wayne, Pennsylvania, USA.
authors.forename: Annie
authors.initials: A
authors.lastname: Guerin
authors.affiliation: Groupe d'analyse, Montreal, Quebec.
authors.forename: Valerie
authors.initials: V
authors.lastname: Carter
authors.affiliation: Vertex Pharmaceuticals, Cambridge, Massachusetts, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Hodgkins
authors.affiliation: Center for Pediatric Excellence, Ottawa, Ontario.
authors.forename: Judy
authors.initials: J
authors.lastname: van Stralen
keywords: ADHD; RAMQ; combination therapy; stimulants; switching