Inhaled versus oral steroids for adults with chronic asthma

Abstract

Background: Steroids are a common treatment of chronic asthma as a maintenance therapy in both developed and developing countries across the world. The cost of inhaled steroids means that in developing countries their availability is limited, leading to poorly controlled asthma in patients who are prescribed low dosage inhaled steroids, or the additional use of oral steroids to control patients' asthma. This review seeks to determine what dosage of oral steroids equates to the therapeutic effects of a moderate to high doses of inhaled steroids. Objectives: To determine therapeutically equivalent doses of inhaled versus oral steroids for adults with chronic asthma. Search methods: The Cochrane Airways Group trials register was searched and experts in the field were contacted. Searches were current as of August 2008. Selection criteria: Randomised controlled trials were selected of at least 4 weeks duration and included patients over the age of 15 years with chronic asthma. Trials compared inhaled steroids and oral prednisolone or prednisone; where the maximum dose for inhaled steroids was 2000 mcg/day and prednisolone 60 mg (on alternate days). Data collection and analysis: Two independent reviewers screened 1285 titles and abstracts from the electronic search, bibliography searches and other contacts. Of these, 10 trials met previously defined inclusion criteria. Two reviewers independently extracted study characteristics, and outcome measures. Main results: All trials were small and no data could be pooled. Carry-over effects were present in at least one cross-over trial. Data from six trials produced the same pattern, in which prednisolone 7.5-12 mg/day appeared to be as effective as inhaled steroid 300-2000 mcg/day. In two trials, inhaled steroid 300-400 mcg/day was more effective than prednisolone 5 mg/day. All doses of inhaled steroid appeared to be more effective than alternate day doses of prednisolone up to 60 mg on alternate days. Side-effect data were reported too variably to permit comparisons. A 30% incidence was reported in one study in patients receiving prednisolone 5 mg/day, none were reported in patients on inhaled steroids. Authors' conclusions: A daily dose of prednisolone 7.5-10 mg/day appears to be equivalent to moderate-high dose inhaled corticosteroids. Side-effects may be present on low doses, so if there is no alternative to oral steroids, the lowest effective dose should be prescribed.