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Am Fam Physician. 2017;95(6):online

Clinical Question

Is a single dose of dexamethasone as effective as five days of prednisone for acute exacerbations of asthma?

Bottom Line

A single dose of 12-mg dexamethasone, which has a longer duration of action than prednisone, is almost as effective as five days of 60-mg prednisone for the prevention of relapse in adults with acute asthma treated in an emergency department. It is a reasonable option for treatment in the emergency department, given its fewer adverse effects. In this study, patients who received the single dose also took placebo for four days. Further research is needed to determine whether patients are comfortable with taking just a single dose. (Level of Evidence = 2b)


These investigators enrolled 465 adults younger than 56 years who presented with acute asthma to an emergency department and required at least one treatment with a beta agonist. The patients were randomly assigned, using concealed allocation, to receive treatment with prednisone, 60 mg daily, for five days or a single dose of dexamethasone, 12 mg, followed by four days of placebo. Treatment was started in the emergency department. Of the 465 persons initially enrolled, 376 could be evaluated; 16 were admitted before leaving the emergency department and 73 could not be contacted (more in the dexamethasone group). Over the subsequent two weeks, 12.1% of the dexamethasone group and 9.8% of the prednisone group had a relapse that required additional treatment (difference = 2.3%; 95% confidence interval, −4.1% to 8.6%). This difference did not meet the researchers' threshold for noninferiority of 8%, meaning that treatment with dexamethasone was slightly less effective. The hospitalization rate was low (3%) and did not differ between treatment groups. Adverse effects were more common in the prednisone group.

Study design: Randomized controlled trial (double-blinded)

Funding source: Foundation

Allocation: Concealed

Setting: Emergency department

Reference: RehrerMWLiuBRodriguezMLamJAlterHJA randomized controlled noninferiority trial of single dose of oral dexamethasone versus 5 days of oral prednisone in acute adult asthma. Ann Emerg Med2016;68(5):608–613.

POEMs (patient-oriented evidence that matters) are provided by Essential Evidence Plus, a point-of-care clinical decision support system published by Wiley-Blackwell. For more information, see Copyright Wiley-Blackwell. Used with permission.

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This series is coordinated by Natasha J. Pyzocha, DO, contributing editor.

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