Background: In a previous study, we found that two years of treatment with an inhaled corticosteroid, budesonide, was more effective than treatment with an inhaled beta 2-agonist, terbutaline, in patients with newly diagnosed, generally mild asthma. We continued this study for a third year to investigate whether the steroid dose could be reduced or discontinued and what effect crossover of patients from beta 2-agonist therapy to corticosteroid therapy would have.
Methods: A total of 37 patients treated for two years with inhaled budesonide at a dose of 1200 micrograms per day were randomly assigned to treatment with 400 micrograms of budesonide per day (19 patients) or placebo (18 patients) in a double-blind manner. Another 37 patients, who had received terbutaline during the first two years, were crossed over in an open-label manner to treatment with 1200 micrograms of budesonide per day during the third year.
Results: Treatment with the reduced dose of budesonide was sufficiently effective in 74 percent of the patients to maintain bronchial responsiveness at a level similar to that achieved with the higher dose. In contrast, improvement was maintained in only 33 percent of the patients receiving placebo, and the differences in pulmonary function between the steroid and placebo groups were significant (for forced expiratory volume in one second, P = 0.007; for bronchial responsiveness to histamine, P = 0.025; and for peak expiratory flow in the morning, P = 0.040). The condition of patients who were crossed over from terbutaline therapy to treatment with 1200 micrograms of budesonide per day improved. However, the degree of improvement in these patients appeared to be less than in those who were treated with budesonide at the beginning of the three-year study.
Conclusions: Early treatment with inhaled budesonide results in long-lasting control of mild asthma. Maintenance therapy can usually be given at a reduced dose, but discontinuation of treatment is often accompanied by exacerbation of the disease.