EFFECT OF LONG-TERM TREATMENT WITH OXITROPIUM BROMIDE ON AIRWAY SECRETION IN CHRONIC-BRONCHITIS AND DIFFUSE PANBRONCHIOLITIS

Background - Anticholinergic bronchodilator drugs improve lung functio n in chronic bronchitis but less is known of their effects on the volu me and physical properties of sputum in conditions associated with exc essive airway secretions. This study examines the effects of the regul ar use of oxitropium bromide in such patients. Methods - The study was conducted in a parallel, double blind, placebo controlled fashion. Pa tients were divided into two groups: the first group (n=17) received o xitropium bromide from a metered dose inhaler (two puffs three times d aily; 100 mu g/puff) for eight weeks, and the second group (n=16) rece ived placebo. Lung function was measured as forced expiratory volume i n one second (FEV(1)) and vital capacity. In evaluating airway secreti on, daily amount of expectorated sputum, percentage solid composition, viscoelastic properties including elastic modulus and dynamic viscosi ty, and sputum microbiology were determined. Results - Oxitropium brom ide increased FEV(1) and decreased the mean (SE) sputum production fro m 61(4) to 42(3) g/day after treatment, whereas placebo had no effect. Bacterial density and sputum flora were unchanged, but solid composit ion and elastic modulus increased from 2.52(0.43)% to 3.12 (0.34)%, an d 68(12) dyne/ cm(2), respectively, in the group taking oxitropium bro mide. Conclusions - Regular treatment with oxitropium bromide not only improves airflow limitation but also reduces sputum production, proba bly through the inhibition of both mucus secretion and water transport , the latter component being predominant.