The bronchodilator effects of aerosolized terbutaline. A controlled, double-blind study

The bronchodilator effects of aerosols of a high-dose of terbutaline sulfate (1.5 mg), a low-dose of terbutaline sulfate (0.75 mg), isoproterenol (0.3 mg), and placebo were compared using forced expiratory spirometry, flow-volume curves, and body plethysmography in a double-blind, six-hour, controlled study in 25 patients with reversible airflow obstruction. After isoproterenol therapy, the values peaked at 15 minutes, and none were significantly different (P less than .05) from placebo after the 30-minute observation point. The values for high-dose terbutaline peaked at one hour at a level that exceeded responses to isoproterenol. All values except the forced vital capacity at five and six hours and functional residual capacity at six hours were significantly greater than placebo (P less than .05) at all observation points. The low-dose terbutaline values peaked earlier and at a lower value than the high-dose terbutaline values, and several indexes were significantly greater (P less than .05) than after isoproterenol therapy beyond the two-hour point.