Comparison of two aerosols containing both fenoterol and ipratropium in a high (Duovent) and low (Berodual) concentration, respectively.

Twenty-one stable asthmatic patients were randomly allocated to be treated with either Duovent (ipratropium bromide 40 micrograms and fenoterol 100 micrograms) and Berodual (ipratropium bromide 20 micrograms and fenoterol 50 micrograms) in a cross-over double-blind design over a 12-week period, each treatment period lasting for 6 weeks. During the study, patients used the test medicine 2 puffs 4 times daily. At the day of inclusion, 6 and 12 weeks after start, a dose-response curve was obtained after inhalation of the test medicine used during the previous 6-week period. Asthma symptoms were recorded in a diary card and morning and evening peak flow was measured. Berodual and Duovent showed a significant bronchodilating effect, the effect of Duovent comparatively more pronounced, but the absolute lung function values after Berodual equalized the effect of Duovent. No difference between peak flow values measured in the morning and evening could be demonstrated. We conclude that no preference between either Duovent or Berodual could be established in the treatment of asthma.