Long-term effects of budesonide on airway responsiveness and clinical asthma severity in inhaled steroid-dependent asthmatics

Budesonide 400 micrograms daily, in nonsteroid-dependent asthma, can produce improvements in airway responsiveness and clinical asthma severity, with some patients returning to normal responsiveness and becoming asymptomatic. This study examined whether similar improvements occur when asthmatics, who are dependent upon inhaled steroids, take either a regular maintenance dose of inhaled steroid or twice that amount for a year. Thirty two asthmatics were each stabilized on the minimum amount of inhaled steroid that would keep symptoms non-troublesome. In a double-blind, randomized manner, half were assigned to remain on a maintenance dose (MD) and the rest received twice that dose (MDx2) for one year. Before and monthly throughout the study, airway responsiveness to methacholine was measured and clinical asthma severity assessed by questionnaire, inhaled bronchodilator use and number of asthma exacerbations. There was a significant improvement in airway responsiveness and clinical asthma severity in both treatment groups. Those on MDx2 showed the greatest improvement but the difference between the two groups did not reach significance. This study provides strong evidence that prolonged use of inhaled steroids is associated with improvement in airway responsiveness and clinical asthma severity in inhaled steroid-dependent asthma with a suggestion that the improvements are dose related.