Long-term metaproterenol therapy in asthmatic children.

The bronchodilator efficacy and safety of metaproterenol sulfate were evaluated by double-blind crossover tests against placebo at three intervals during a 90-day treatment period in 50 asthmatic children. One group of 25 patients was continuously treated with metaproterenol syrup, and the other 25 with placebo syrup. Pulmonary function tests showed statistically significant improvements in forced expiratory volume, forced expiratory volume in one second, and peak expiratory flow rate after metaproterenol administration as compared with those measurements after treatment with placebo. Biweekly global evaluations of responses to metaproterenol administration were consistently more favorable than responses to placebo. Tachycardia and blood pressure changes after metaproterenol administration were consistent with the pharmacologic properties of beta-sympathomimetic stimulants. Side effects during metaproterenol treatment were minimal and laboratory data remained normal.