Double-blind trial with increasing doses of salbutamol and terbutaline aerosols in patients with reversible airways obstruction

Abstract In a double-blind trial we have tested the effects of inhaling increasing doses of salbutamol and terbutaline aerosol. In 12 patients with reversible airways obstruction we assessed the effects on the airways obstruction by dynamic spirometry and repeated measurements of peak expiratory flow rate (PEFR) over a period of 5 hours after inhalation of 0.10+0.20 mg salbutamol and 0.25+0.50 mg terbutaline. A similar and significant bronchodilation occurred up to 2 hours, with a 50% maximum increase after 1 hour. After 3–4 hours the effect declined, but was still significant. The ventilatory effect of terbutaline was significantly larger than that of salbutamol after 3–5 hours. No consistent significant changes or differences between the drugs were noted concerning pulse rate, BP or subjective side-effects.