Background: The morbidity from obstructive airways disease (asthma and chronic obstructive pulmonary disease) is considerable, and the mortality rate is rising in several countries. It has been hypothesized that long-term improvement in prognosis might result from vigorous bronchodilator or antiinflammatory therapy.
Methods: In a multicenter trial we compared three inhalation regimens in which a beta 2-agonist (terbutaline, 2000 micrograms daily) was combined with a corticosteroid (beclomethasone, 800 micrograms daily), an anticholinergic bronchodilator (ipratropium bromide, 160 micrograms daily), or placebo. Patients with airways hyperresponsiveness and obstruction who were 18 to 60 years old were followed for 2 1/2 years.
Results: Of the 274 patients enrolled, 56 percent had allergies. The mean forced expiratory volume in one second (FEV1) was 64 percent of the predicted value. The mean PC20 (the concentration of inhaled histamine causing a 20 percent decrease in FEV1, a measure of hyperresponsiveness) was 0.26 mg per milliliter. Withdrawal from the study, due mainly to pulmonary symptoms, was less frequent in the corticosteroid group (12 of 91 patients) than in the anticholinergic-drug group (45 of 92 patients) or the placebo group (44 of 91 patients; P < 0.001). The mean FEV1 (+/- SE) increased by 10.3 +/- 1.3 percent of the predicted value in the corticosteroid group within three months and remained stable thereafter, whereas it did not change in the other two groups (P < 0.001). The PC20 increased by 2.0 doubling concentrations in the corticosteroid group but did not change in the other groups (P < 0.001). In the corticosteroid group, patients who did not smoke, who had allergies, or who were less than 40 years old benefited more from their treatment than did those who smoked, did not have allergies, or were over 40, but all subgroups of the corticosteroid group had improvement as compared with the anticholinergic-drug or placebo group.
Conclusions: The addition of an inhaled corticosteroid--but not an inhaled anticholinergic agent--to maintenance treatment with a beta 2-agonist (terbutaline) substantially reduced morbidity, hyperresponsiveness, and airways obstruction in patients with a spectrum of obstructive airways disease.