Inhaled Corticosteroids Monotherapy in Childhood Asthma: Any Differential Response Rate between Activated and Prodrugs?

OBJECTIVE: The efficacy of inhaled corticosteroids (ICS) as prodrugs (inactive at delivery) has been compared to activated ICS, in mean changes in lung function and symptoms, with limited evidence on achieving control. We aimed to compare the real-life success rate of two broad ICS types (prodrug and activated) to prevent poor asthma control and exacerbations in children with asthma. METHODS: We conducted a retrospective cohort study of children aged 1-17 years, initiating a new maintenance ICS monotherapy at low or medium doses. Initiation referred to a new ICS (after ≥2-month washout) or a switch to another ICS type (prodrug or activated). Co-primary outcomes included: unsatisfactory asthma control, measured by the Pharmacoepidemiologic Pediatric Asthma Control Index, and occurrence of ≥1 severe exacerbation, in following 6 months. A propensity score (PS) weight-adjusted binary logistic regression compared outcomes between ICS types, reporting odds ratios [95% confidence intervals]. RESULTS: Of 213 participants (56% male, median age: 6.9 years), 194 were incident users and 19, switchers. Most (N = 148) children were prescribed an activated ICS (97.3% fluticasone propionate, 2.7% budesonide) and 65, an ICS prodrug (100% ciclesonide), 61% using low-dose ICS. The PS-adjusted odds of unsatisfactory asthma control were significantly higher in the prodrug than activated ICS groups (adjOR: 2.35 [95% CI: 1.46-3.81]), with no significant group difference in severe exacerbations (adjOR: 0.92 [95% CI: 0.49-1.72]). CONCLUSIONS: Compared to activated ICS, children initiating a prodrug were two-fold more likely to display unsatisfactory control, with no significant difference nor equivalence in likelihood of severe exacerbations.