Effects of allergy and age on responses to salbutamol and ipratropium bromide in moderate asthma and chronic bronchitis.

The bronchodilating responses to 400 micrograms salbutamol and 80 micrograms ipratropium bromide were studied in 188 patients with chronic bronchitis (n = 113) or asthma (n = 75) and mild to moderate airflow obstruction (forced expiratory volume in one second (FEV1) above 50% but below 2 SD of predicted value) in a crossover study on two days a week apart. Both the patients with asthma and the patients with chronic bronchitis varied considerably in their responses to the salbutamol and the ipratropium bromide. The mean increase in FEV1 in the subjects with asthma was higher after salbutamol (0.371 or 18% of the prebronchodilator value) than after ipratropium bromide (0.26 1 or 13%). In chronic bronchitis there was no difference between the increase in FEV1 after salbutamol (0.161 or 7%) and after ipratropium bromide (0.191 or 8%). When patients were categorised into those with a better response to salbutamol 400 micrograms and those with a better response to ipratropium bromide 80 micrograms, patients with chronic bronchitis responded better in general to ipratropium bromide whereas asthmatic patients responded better to salbutamol. The response pattern was also related to allergy and age, allergic patients and patients under 60 being more likely to respond better to salbutamol 400 micrograms than non-allergic patients and older patients, who benefited more from ipratropium bromide 80 micrograms. The response pattern was not related to sex, smoking habits, lung function, bronchial reactivity, respiratory symptoms, or number of exacerbations during the preceding year.