Effect of prednisone and beclomethasone diproprionate

To examine the effect of corticosteroids on bronchial hyperresponsiveness, a randomised, double dummy, single blind crossover study was performed in 18 subjects with chronic asthma, comparing the effect of three weeks' treatment with inhaled beclomethasone dipropionate, 1200 ,ug daily, and oral prednisone 12 5 mg daily. The 12 week study began with a three week run in period of baseline treatment, which was continued unchanged throughout the study, and the two treatment periods were separated by a three week washout period. Patients kept daily Airflometer readings and attended the laboratory every three weeks for spirometry and a histamine inhalation test for determining the provocative dose ofhistamine causing a 20% fall in FEV1 (PD20). The mean FEV, at the start was 1 9 litres (56% predicted). There was no significant change in PD20 with prednisone treatment, the mean PD20 being 0 56 and 0 59 umol before and after treatment. There was, however, a significant improvement in PD20 with beclomethasone dipropionate treatment, the geometric mean PD20 being 0 38 and 1 01 umol before and after treatment (p < 0-001). There was a small but significant improvement in mean FEVY after beclomethasone dipropionate treatment-from 1-9 to 2 2 litres-but no change after prednisone. Both medications produced significant and similar improvements in morning and evening Airflometer readings, post-bronchodilator improvement, and diurnal variation. Thus at doses that had similar beneficial effects on lung function beclomethasone dipropionate caused a significant improvement in bronchial hyperresponsiveness whereas prednisone caused no change. The superior topical anti-inflammatory effect of beclomethasone dipropionate may account for the different effects on bronchial hyperresponsiveness. Although the mechanisms underlying bronchial hyperresponsiveness in asthma are still poorly understood, there is increasing evidence that airway inflammation has a major role in its development and maintenance.' Corticosteroids have been shown to diminish bronchial hyperresponsiveness caused by methacholine when this is given orally in high doses45 and to reverse allergen induced increases in responsiveness.' Several studies, however, have failed to show any effect of oral corticosteroids on bronchial hyperresponsiveness.78 More recent studies suggest that inhaled corticosteroids may be more effective in reducing it, although the magnitude of response in different studies has been variable.9'" As no prospective study of the effect of equipotent doses of oral and inhaled corticosteroids has been Address for reprint requests: Dr C Jenkins, Institute of Respiratory Medicine, Royal Prince Alfred Hospital, Camperdown, New South Wales, 2050, Australia. Accepted 9 November 1987 performed, the present study was designed to compare the relative efficacy of an inhaled corticosteroid (beclomethasone dipropionate) with an oral corticosteroid (prednisone) in reducing bronchial hyperresponsiveness in subjects with moderately severe asthma. Patients kept a daily record ofmorning and evening Airflometer readings recorded before and 15 minutes after taking a bronchodilator. The Airflometer is a portable home monitoring device requiring a forced vital capacity manoeuvre to obtain a reading. It has been shown to give reproducible results that correlate closely with spirometric indices incorporating both FEV, and FVC. The reading is influenced by both expiratory volume and flow rate.'2