Two days of dexamethasone versus 5 days of prednisone in the treatment of acute asthma: a randomized controlled trial.

Study Objective: Dexamethasone has a longer half-life than prednisone and is well tolerated orally. We compare the time needed to return to normal activity and the frequency of relapse after acute exacerbation in adults receiving either 5 days of prednisone or 2 days of dexamethasone.

Methods: We randomized adult emergency department patients (aged 18 to 45 years) with acute exacerbations of asthma (peak expiratory flow rate less than 80% of ideal) to receive either 50 mg of daily oral prednisone for 5 days or 16 mg of daily oral dexamethasone for 2 days. Outcomes were assessed by telephone follow-up.

Results: Ninety-six prednisone and 104 dexamethasone subjects completed the study regimen and follow-up. More patients in the dexamethasone group reported a return to normal activities within 3 days compared with the prednisone group (90% versus 80%; difference 10%; 95% confidence interval 0% to 20%; P=.049). Relapse was similar between groups (13% versus 11%; difference 2%; 95% confidence interval -7% to 11%, P=.67).

Conclusion: In acute exacerbations of asthma in adults, 2 days of oral dexamethasone is at least as effective as 5 days of oral prednisone in returning patients to their normal level of activity and preventing relapse.