A combination of the inhaled corticosteroid budesonide and the long-acting ?2-agonist formoterol has been formulated in a novel dry powder inhaler, Spiromax(?). The objective was to compare lower leg growth in children with asthma treated with inhaled budesonide+formoterol (BF) delivered from the Spiromax inhaler with BF from the Symbicort Turbohaler(?).
Prepubescent children with persistent asthma (n=75, aged 6-11 years) were included in a randomized, double-blind, double-dummy, placebo-controlled, three-way crossover study with active treatment and placebo periods of 2 weeks duration. Lower leg length was measured every second week. As a secondary outcome parameter, 24-hr urine was collected for assessment of free cortisol. Interventions were dry powder BF 160+9??g twice daily (b.i.d.; delivered dose) from the Spiromax inhaler and dry powder BF 200+12??g b.i.d. (metered dose) from the Symbicort Turbohaler.
The least squares mean difference in lower leg growth rates (LLGR) between BF Spiromax and Symbicort Turbohaler was -0.086?mm/week [95% confidence interval (CI) -0.203, 0.032]. The pre-specified non-inferiority margin was -0.200?mm/week, so the lower limit of the 95% CI was just outside this margin. The difference between BF Spiromax and placebo was -0.20?mm/week (95% CI: -0.322, 0.086); p