[Inhaled beclomethasone in long-term management of asthma: optimal dose and optimal duration of treatment]

Abstract

We studied the usefulness of 24 weeks of therapy with inhaled beclomethasone dipropionate (BDP) in the management of mild and moderately severe asthma in adults. To determine the optimal dose and treatment duration, the patients were divided into three groups. Patients in group I (n = 10) were treated with bronchodilators but no BDP. Patients in group II (n = 12) received bronchodilators and 450 micrograms/day of BDP. Patients in group III (n = 17) received bronchodilators and 900 micrograms/day of BDP. BDP was inhaled via a large spacer (Volumatic). Asthma scores were measured before treatment began, and again every 2 weeks for the duration of the study (26 weeks). Peak expiratory flows (PEF) were measured before treatment began, 2 weeks after treatment had begun, and again every four weeks until the end of the study. Vital capacity, FEV1, and bronchial reactivity to methacholine were measured before treatment began, and again 12 weeks and 24 weeks after it had begun. Adrenocortical function in patients in group III was measured with a rapid ACTH test, at the same time as the pulmonary functions were measured. The results were: 1) Asthma scores decreased more in patients who received the higher dose of BDP than in those who received the lower dose, especially during the second 12 weeks. 2) After two weeks of treatment, %PEF had increased significantly in both groups that received BDP, but after six weeks of treatment there was no further improvement. %PEF did not improve in the group given bronchodilators only. 3) In the patients whose baseline %PEF was less than 80%, only the higher dose of BDP significantly increased %PEF. 4) Only the higher dose of BDP increased the %VC, the FEV1%, and the PD20 for methacholine. 5) Asthma type and severity were not related to the usefulness of BDP therapy. 6) Results of the rapid ACTH test indicated that the higher dose of BDP did not suppress adrenocortical function. These data indicate that 900 micrograms of BDP per day is more effective than 450 micrograms/day as initial therapy for long-term management of mild or moderate asthma in adults, and that the dose of BDP should be reviewed after 3 months of treatment. Patients in whom asthma is well-controlled may tolerate a reduction in dose, and those in whom asthma is not well-controlled may require a higher dose.