From the Cochrane Library:
Description of the intervention
Systemic corticosteroids are potent general anti-inflammatory agents for the treatment of asthma (Alangari 2014). When given in the ED, systemic corticosteroids can reduce the risk for hospitalisation and improve lung function in patients with acute asthma (Rowe 2001). A Cochrane Review reported significant decreases in symptom scores following discharge from the ED with systemic corticosteroids, but heterogeneity in outcome reporting prohibited meaningful pooling (Rowe 2007). Treatment with systemic corticosteroids at discharge has also been shown to prevent relapse (Rowe 2007). Current guidelines recommend that discharge management of patients with all but the mildest presentations of acute asthma from the ED include systemic corticosteroids to prevent relapse (GINA 2016). While systemic corticosteroids can effectively prevent asthma relapses, the optimal route of administration is less clear.
How the intervention might work
At discharge from the ED or acute care setting, systemic corticosteroids maybe provided via intramuscular (IM) or oral routes of administration. A single dose of IM corticosteroids has long-acting pharmacokinetic properties, with fewer side effects associated with nausea/vomiting, but pain and swelling around the injection site can occur (Lahn 2004). Oral corticosteroids have short-acting properties, and patients are typically provided with a short-course of oral corticosteroids for five to seven days (GINA 2016). While no injection is needed, side effects associated with oral corticosteroids often include nausea and vomiting, and adherence/compliance with oral corticosteroid regimens is often suboptimal (Ducharme 2011). While it seems that IM corticosteroids could be alternative treatment option for patients with palatability or adherence/compliance issues with oral corticosteroids, it is unclear whether IM corticosteroids are as effective as oral corticosteroids in mitigating relapse.
Why it is important to do this review
While the effectiveness of systemic corticosteroids is known (Rowe 2007), and widely accepted by clinicians, whether patients benefit more from IM or oral corticosteroids is less clear. A previous umbrella review reported no differences in relapse events in adults after treatment with IM or oral corticosteroids for acute asthma (Krishnan 2009); however, this review was limited to English-language studies. Since Krishnan 2009 was published, no systematic reviews have been conducted that have used an extensive literature search to synthesize all of the available evidence from studies that have compared IM to oral corticosteroids.