Therapeutic equivalence of a fenoterol/ipratropium bromide combination (Berodual) inhaled as a dry powder and by metered dose inhaler in chronic obstructive airway disease.

Abstract

A randomized double-blind cross-over study was performed to compare the bronchodilator effects of a fenoterol/ipratropium bromide combination (Berodual) when inhaled as a dry powder and by metered dose inhaler (MDI) in an equal doses (fenoterol 100 micrograms + ipratropium bromide 40 micrograms). Thirty-eight patients (29 male, 9 female, mean age 53 years) with reversible chronic obstructive airway disease were studied on 2 separate days by employing the double-dummy technique. The effects of the two modes of administration of the fixed combination were followed by pulmonary function tests [forced expiratory volume (FEV1), forced vital capacity (FVC)] from 15 min up to 6 h after administration. In addition, the pulse rate was recorded just before each pulmonary function test. The FEV1 and FVC time-response curves showed that the dry powder had an overall efficacy profile similar to MDI. Both formulations produced clinically significant improvements in FEV1 in approximately 10 min. Peak effects occurred in 1 h while at 6 h after test drug inhalation there was still an increase in FEV1 of 14%. No safety problems were observed after the use of the test drugs and no clinically significant changes in pulse rate were found. It is concluded that the dry powder of the fenoterol/ipratropium bromide combination provided effective bronchodilation of similar degree and duration to that achieved with the MDI. It would appear, therefore, to be a valuable alternative to MDI.