Oral clenbuterol and procaterol. A double-blind comparison of bronchodilator effects in children with chronic asthma.

In a double-blind crossover study, clenbuterol at a dose of 0.75 micrograms/kg, procaterol at a dose of 1.5 micrograms/kg, and placebo, all administered orally, were compared for bronchodilation efficacy. Twelve children aged from 6 to 13 years, with moderate to severe asthma, participated in the trial. Pulmonary function, heart rate, blood pressure, and tremor were evaluated at 30, 60, 90, and 120 minutes and then hourly for 8 hours after administration. Both clenbuterol and procaterol induced a significant change over their baseline values for all the pulmonary function parameters considered. For clenbuterol, the same was also observed in comparison with placebo, while for procaterol this was true only for FEV1 and FEF25-75, while no difference resulted from FVC and PEF. Mild and transient tremor was the only side effect observed. Oral clenbuterol and procaterol were both demonstrated to be safe and effective. However, at the doses studied, clenbuterol had a significantly higher bronchodilator activity lasting up to 8 hours.