Monday, March 27, 2017

Simplifying treatment of acute asthma

- Jennifer Middleton, MD, MPH

A 2 day course of oral dexamethasone emerged as an alternative to a 5 day prednisone course for acute asthma treatment in adults a few years ago, and now a POEM (patient-oriented evidence that matters) reviewed in the current issue of AFP suggests that just one dose of dexamethasone might also be an option.

The study researchers enrolled 465 adults between the ages of 18-56 who were diagnosed with acute asthma in an emergency department (ED). The participants were randomized to either 60 mg of prednisone for 5 days or 12 mg of oral dexamethasone once (followed by four days of placebo). This study used a noninferiority design; the researchers wanted to see if both regimens were equally efficacious regarding the reduction of relapses requiring additional days of steroid treatment. 9.8% of the prednisone group had a relapse compared with 12.1% of the single dose dexamethasone group, which was a statistically significant difference. There was no difference in hospitalization rates or adverse treatment effects between the two groups. Although 5 days of prednisone was more effective at preventing relapse, the researchers felt that the difference between the two treatment arms was small enough, and the benefits of better compliance high enough (since the dexamethasone was given in the ED), to still make it a viable option.

Shorter courses of dexamethasone may also be an option for our patients under the age of 18 with acute asthma. A meta-analysis published last year found that short courses (1-2 days) of dexamethasone were equivalent to longer courses of oral prednisone or prednisolone for children presenting to the ED with acute asthma in preventing relapse. 1-2 day treatment courses are likely easier for children and parents to adhere to, and children may additionally find oral dexamethasone to be more palatable than oral prednisolone. Inhaled anticholinergics are also a useful adjunctive treatment for children with acute asthma (and possibly for adults with severe exacerbations) as reviewed in this 2011 AFP article on the Management of Acute Asthma Exacerbations. The article mentions a 2008 study that found 3 days of prednisone to be equivalent to 5 days for outpatient treatment of acute asthma.

A 2016 Cochrane review on corticosteroid options for acute asthma in adults and children found that existing evidence was insufficient to state whether one type of oral corticosteroid therapy - regardless of specific medication or treatment duration - was superior to another for outpatient treatment of acute asthma, calling for larger, more rigorous trials. It is reassuring, at least, that they did not find any "convincing evidence" that one type of treatment was worse than another regarding rates of relapse, hospitalization, and adverse drug effect. For the time being, we'll need to use patient-centered decision making to arrive at the best treatment plan for each patient with acute asthma, though it certainly seems reasonable to consider shorter durations of oral corticosteroids in uncomplicated pediatric and adult patients. There's an AFP By Topic on Asthma if you'd like to read more.

Having a reliable source for potential practice-changers, like this 1-dose dexamethasone study, can help busy family physicians stay up to date. At the bottom of this most recent AFP POEM are links to several such resources. There's an archive of AFP's published POEMs, complete with a tool to quickly search them by discipline, topic, and/or keyword. The AFP Podcast regularly reviews the POEMs published in AFP like the one above, often adding additional information, angles, and/or resources along the way. The POEM of the Week Podcast with AFP Editor Dr. Mark Ebell is another audio resource that provides concise, thoughtful reviews of studies relevant to primary care.

How do you decide which corticosteroid to prescribe - and for how long - in acute asthma treatment?