EVALUATION OF THE BRONCHODILATING ACTIVITY AND THE TOLERABILITY OF BROXATEROL ADMINISTERED AS A SOLUTION BY INHALATION

The aim of this study was to evaluate the bronchodilating activity and the tolerability of broxaterol (B, CAS 76596-57-1) given as drops by inhalation after single administration at different doses and after repeated administrations for 1 month. Two groups of 12 patients each were treated in a double-blind fashion and according to a within-subject design: one group with B at the single doses of 1.25 mg and 2.50 mg and with placebo (P), and the other with B at the dose of 0.75 mg and with P. A further group of 12 patients was treated in open fashion for 1 month with B at the dose of 1.25 mg 3 times a day. On each study day for the single doses and on the 1st and 30th days for the repeated doses, forced vital capacity (FVC), forced expiratory volume (FEV1), maximal middle expiratory flow (MMEF), heart rate (HR) and systolic and diastolic blood pressure (BP) were measured immediately before and 15, 30, 60, 120 and 240 min after the conclusion of the treatment. At the beginning and at the end of the 1-month treatment period, haematology and biochemistry were checked. After B 0.75 mg, 1.25 mg and 2.50 mg the values of spirometric variables proved significantly and dose-dependently higher than the basal values. The changes from baseline in lung function test values with B (all doses) were significantly greater than with P After 1 month of treatment the basal values of spirometric variables proved significantly higher than on the 1st day; similarly, on the 30th day, (after B) the values of these variables were, on the average, higher than on the 1st day. Changes in HR and BP after each dose of B and on the 1st and 30th treatment days, were always slight and not clinically, although sometimes statistically, significant. Slight tremors were observed in some patients after both B and P; no adverse events were observed or reported during the 1-month treatment. Haematological and biochemical test values were within the normal range in all patients at the start and at the end of the treatment period.