Background: Options for step-down therapy include use of inhaled corticosteroids alone or in combination with a long-acting beta2-agonist.
Objective: We sought to evaluate step-down therapy with a fluticasone propionate-salmeterol (FP-SM) combination administered through a dry powder inhaler (DPI; Advair Diskus) versus a medium dose of hydrofluoroalkane 143a-beclomethasone dipropionate (HFA-BDP) administered through a breath-actuated pressurized metered-dose inhaler (QVAR Autohaler).
Methods: Thirty-nine patients with uncontrolled moderate-to-severe asthma were treated with 1000 microg of DPI-administered BDP twice daily (DPI-BDP) for 4 weeks and then randomized to 200 microg of HFA-BDP twice daily (n = 20) or 100 microg of FP and 50 microg of SM twice daily (FM-SM; n = 19) for 8 weeks in a double-blind, double-dummy, parallel-group design. We measured the provocative dose of methacholine producing a 20% fall in FEV1 (methacholine PD20) as the primary outcome, with secondary outcomes being lung function, surrogate inflammatory markers, diary card responses, quality of life, and safety.
Results: There was a 0.9 (95% confidence interval, 0.5-1.2) doubling dose improvement in methacholine PD20 comparing asthma before versus after DPI-BDP. HFA-BDP maintained this improvement, whereas FP-SM produced a further significant improvement, amounting to a 1.1 (95% confidence interval, 0.2-2.1) doubling dose difference at 8 weeks for FP-SM versus HFA-BDP. Effects on FEV1, peak expiratory flow, and quality of life (symptoms and emotions) were similar to those on methacholine PD20, with a significant difference between FP-SM and HFA-BDP. Suppression of plasma and urinary cortisol and serum osteocalcin levels occurred with DPI-BDP, but values returned to baseline levels within 1 month of HFA-BDP or FP-SM administration.
Conclusion: After high-dose inhaled corticosteroid, stepping down with the combination inhaler conferred further improvements in bronchoprotection, bronchodilatation, and clinical control, but not inflammatory markers, compared with that seen with a medium dose of inhaled corticosteroid.