Impact of dosage timing of once-daily inhaled corticosteroids in asthma: A systematic review and meta-analysis.

BACKGROUND: Once-daily inhaled corticosteroids (ICSs) are widely used as first-line therapy in patients with asthma.

OBJECTIVE: To compare the efficacy of ICSs administered once daily in the morning or evening as determined by lung function.

METHODS: Medline, Embase, and the Cochrane Central Register were searched for relevant clinical trials. The primary outcome was lung function assessed as trough forced expiratory volume in 1 second and peak expiratory flow at end point.

RESULTS: Eight randomized clinical trials involving 1,234 patients were analyzed. The total number of patients treated with once-daily ICS in the morning and evening was 628 and 606, respectively. Pooled estimates showed that ICS administered once daily in the evening resulted in mild improvements in trough forced expiratory volume in 1 second (mean difference 0.05 L; 95% confidence interval 0.01-0.09; P = .026; I2  = 22.5%) and morning peak expiratory flow (mean difference 13.92 L/min; 95% confidence interval 5.77-22.06; P = .001; I2  = 13%) at end point compared with morning dosing. The change in use of rescue medicine and the incidence of adverse events with once-daily ICS were not significantly different between the 2 dosing times.

CONCLUSION: Compared with morning dosing, ICSs administered once daily in the evening seemed to provide some benefits in lung function for patients with asthma. However, because of methodologic limitations, further large-scale randomized clinical trials for dosing time of once-daily ICSs are needed.