Comparison of oral-steroid sparing by high-dose and low-dose inhaled steroid in maintenance treatment of severe asthma.

It is not clear whether high doses of inhaled steroids have a greater sparing effect than low doses on the requirement for systemic steroids. In a randomised, double-blind, multicentre study, we compared the effects of high-dose (1500 micrograms/day) and low-dose (300 micrograms/day) inhaled beclomethasone dipropionate (BDP) in patients with severe asthma requiring a daily oral prednisolone dose of 10-40 mg. During a 3-month run-in period, we tried to achieve optimum asthma control by means of oral steroid and inhaled BDP 300 micrograms/day. The patients were then allocated to high-dose (n = 71) or low-dose (n = 72) treatment by an independent observer who took into account various prognostic factors. BDP was administered by means of an aerosol inhaler with a spacer device. The dose of systemic steroid was reduced as much as possible during the 6-month study period while keeping the peak expiratory flow (PEF) constant and asthma clinically stable. There was no difference between the low-dose and high-dose treatment groups in the mean reduction in oral prednisolone dose achieved by the end of the study (5.2[ SD 7.9] vs 5.0 [9.4] mg/day). The maximum response to inhaled steroid was seen, however, only after several months' therapy in both groups. There were no differences between the groups in use of on-demand beta-agonist inhalations or in asthma symptoms, and PEF values were constant throughout the study. Both doses of BDP were well tolerated. High doses of inhaled steroid offer no further benefit over low doses in the maintenance treatment of severe steroid-dependent asthma when the inhaled steroid is administered with a spacer device.