INFLUENCE OF 1-YEAR TREATMENT PERIOD ON RESPONSES TO ANTICHOLINERGIC INHALATION IN PATIENTS WITH CHRONIC-OBSTRUCTIVE-PULMONARY-DISEASE

Although acute responses to anticholinergic drugs in chronic obstructi ve pulmonary disease (COPD) have been extensively reported, it is not clear whether the response to these drugs is affected by their long-te rm nse, me assessed the bronchodilator response at rest and the ventil atory response during exercise to the anticholinergic inhalational dru g oxitropium bromide (OTB) in patients with COPD. We performed both sp irometry and symptom-limited testing repeatedly on 14 men with COPD (a ge from 60 to 79 years; mean +/- SE, 70.3 +/- 2.0 years) before and af ter inhalation of OTB and repeated these tests after 1 year, The posti nhalational forced expiratory volume in 1 second (FEV(1)) was statisti cally significantly greater than the preinhalational value both before (baseline measures) and after 1 year of OTB use (baseline, 1.35 +/- 0 .07 to 1.49 +/- 0.08 L [mean +/- SE]; 1 year after, 1.29 +/- 0.07 to 1 .43 +/- 0.08 L [mean +/- SE]), Bronchodilator response as indicated by the absolute change in FEV(1) (Delta FEV(1)) and the percent change o f FEV(1) in the study after 1 year was virtually unchanged from values at baseline, The exercise capacity as measured by the maximal oxygen uptake was increased by the inhalation of OTB both before and after 1- year use of the drug (baseline, 1034 +/- 31 to 1146 +/- 48 mL/min [mea n +/- SE]; 1 year after, 1006 +/- 36 to 1088 +/- 51 mL/min [mean +/- S E]), These results suggest that the duration of treatment with the ant icholinergic drug OTB may have Little effect on the resulting improvem ent in bronchodilation and exercise performance.