A Randomized Controlled Noninferiority Trial of Single Dose of Oral Dexamethasone Versus 5 Days of Oral Prednisone in Acute Adult Asthma

Study objective: Oral dexamethasone demonstrates bioavailability similar to that of oral prednisone but has a longer half-life. We evaluate whether a single dose of oral dexamethasone plus 4 days of placebo is not inferior to 5 days of oral prednisone in treatment of adults with mild to moderate asthma exacerbations to prevent relapse defined as an unscheduled return visit for additional treatment for persistent or worsening asthma within 14 days.

Methods: Adult emergency department patients (aged 18 to 55 years) were randomized to receive either a single dose of 12 mg of oral dexamethasone with 4 days of placebo or a 5-day course of oral prednisone 60 mg a day. Outcomes including relapse were assessed by a follow-up telephone interview at 2 weeks.

Results: One hundred seventy-three dexamethasone and 203 prednisone subjects completed the study regimen and telephone follow-up. The dexamethasone group by a small margin surpassed the preset 8% difference between groups for noninferiority in relapse rates within 14 days (12.1% versus 9.8%; difference 2.3%; 95% confidence interval -4.1% to 8.6%). Subjects in the 2 groups had similar rates of hospitalization for their relapse visit (dexamethasone 3.4% versus prednisone 2.9%; difference 0.5%; 95% confidence interval -4.1% to 3.1%). Adverse effect rates were generally the same in the 2 groups.

Conclusion: A single dose of oral dexamethasone did not demonstrate noninferiority to prednisone for 5 days by a very small margin for treatment of adults with mild to moderate asthma exacerbations. Enhanced compliance and convenience may support the use of dexamethasone regardless.