Inhaled vs oral steroids for adults with chronic asthma

To determine therapeutically equivalent doses of inhaled versus oral steroids for adults with chronic asthma.

The Cochrane Airways Group trials register was searched using the terms: (drug delivery systems OR ((nebuli* OR inhal* OR MDI) AND oral*)) AND ( steroid* OR corticosteroid* OR glucocorticoid* OR beclomethasone OR betamethasone OR fluticasone OR cortisone OR dexamethasone OR hydrocortisone OR prednisolone OR prednisone OR triamcinolone).

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).

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.

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. A further search was conducted in October 2000 which yielded no further trials.

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.