title: Addition of antileukotriene agents to inhaled corticosteroids in children with persistent asthma.
abstract: For the current issue of the Journal, we asked Drs Jimmy Chong and Bhupendrasinh Chauhan to comment on and put into context the Cochrane Review on the efficacy and safety of adding antileukotriene agents (LTRAs) to low-dose inhaled corticosteroids (ICS) in children with persistent asthma (1).
  
  
  BACKGROUND
  In the treatment of children with mild persistent asthma, low-dose ICS are recommended as the preferred monotherapy (referred to as step 2 of therapy). In children with inadequate asthma control on low doses of ICS (step 2), asthma management guidelines recommend adding an LTRA to existing ICS as one of three therapeutic options to intensify therapy (step 3).
  
  
  METHODS
  
  
  
  METHODS
  Trials were identified from the Cochrane Airways Group Specialised Register of Trials, which is derived from systematic searches of bibliographical databases, including the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, PsycINFO, AMED and CINAHL, and a manual search of respiratory journals and meeting abstracts, as well as the web-site www.clinicaltrials.gov. The search was conducted until January 2013.
  
  
  METHODS
  Randomized controlled trials (RCTs) that involved children and adolescents one to 18 years of age, with asthma, who remained symptomatic despite the use of a stable maintenance dose of ICS, and in whom LTRAs were added to ICS and compared with the same, an increased or a tapering dose of ICS for at least four weeks were considered for inclusion.
  
  
  METHODS
  Sandard methods outlined by The Cochrane Collaboration were used.
  
  
  RESULTS
  Five paediatric (parallel group or cross-over) trials met the inclusion criteria. Two (40%) trials were considered to be at a low risk for bias. Four published trials, representing 559 children (≥6 years of age) and adolescents with mild-to-moderate asthma, contributed data to the review. No trial enrolled preschool-age children. All trials used montelukast as the LTRA, administered for between four and 16 weeks. Three trials evaluated the combination of LTRAs and ICS compared with the same dose of ICS alone (step 3 versus step 2). No statistically significant group difference was observed in the only trial reporting participants with exacerbations requiring oral corticosteroids over four weeks (n=268 participants; RR 0.80 [95% CI 0.34 to 1.91]). There was also no statistically significant difference in percent change in forced expiratory volume in 1 s (FEV1) in this trial, with a mean difference (MD) of 1.3 (95% CI -0.09 to 2.69); however, a significant group difference was observed in the morning and evening peak expiratory flow rates: n=218 participants; MD 9.70 L/min (95% CI 1.27 L/min to 18.13 L/min) and MD 10.70 L/min (95% CI 2.41 L/min to 18.99 L/min), respectively. One trial compared the combination of LTRAs and ICS with a higher dose of ICS (step 3 versus step 3). No significant group difference was observed in this trial for participants with exacerbations requiring rescue oral corticosteroids over a 16-week period (n=182 participants; RR 0.82 [95% CI 0.54 to 1.25]), nor was there any significant difference in exacerbations requiring hospitalization. There was no statistically significant group difference in withdrawals overall or because of any cause with either protocol. No trial explored the impact of adding LTRAs as a means to taper the dose of ICS.
  
  
  CONCLUSIONS
  The addition of LTRAs to ICS is not associated with a statistically significant reduction in the need for rescue oral corticosteroids or hospital admission compared with the same or an increased dose of ICS in children and adolescents with mild to moderate asthma. Although LTRAs have been licensed for use in children for >10 years, the paucity of paediatric trials, the absence of data regarding preschool-age children and the variability in the reporting of relevant clinical outcomes considerably limit firm conclusions. At present, there is no firm evidence to support the efficacy and safety of LTRAs as add-on therapy to ICS as a step 3 option in the therapeutic arsenal for children with uncontrolled asthma symptoms on low-dose ICS. The full text of the Cochrane Review is available in The Cochrane Library (1).
authors.affiliation: University of Auckland, Auckland, New Zealand;
authors.forename: Jimmy K
authors.initials: JK
authors.lastname: Chong
authors.affiliation: CHU Sainte-Justine, Montreal, Quebec.
authors.forename: Bhupendrasinh F
authors.initials: BF
authors.lastname: Chauhan