Bronchodilating activity of oral clenbuterol in asthmatic children after single administration of different dosages.
The dose-response activity of clenbuterol, a new long-acting beta 2-agonist, was evaluated in 12 children aged 5 to 11 years with moderate to severe asthma. The study was a double-blind cross-over comparison of three oral dose levels: 0.5, 1.0, and 1.5 micrograms/kg and placebo all in the form of syrup. Pulmonary function, heart rate, blood pressure, and tremor were evaluated at 30, 60, 90, and 120 min, then hourly for 8 hr, following the ingestion of the drug. The bronchodilating effect of clenbuterol, evaluated as percentage changes in expiratory flow rates was significantly different from placebo. The overall fall-off in the effect of 1.0 micrograms/kg and 1.5 micrograms/kg doses after 8 hr was small. The results of the 1.0 micrograms/kg dose often overlapped those of the 1.5 micrograms/kg dose, suggesting that a single 1.0 micrograms/kg dose of clenbuterol is most advisable in children, assuring the most favorable risk/benefit ratio. Even the highest dose of clenbuterol caused only a marginal increase in tremor, not statistically different from that induced by placebo.
D000284:Administration, Oral; D001249:Asthma / Q000188:drug therapy*; D002648:Child; D002675:Child, Preschool; D002976:Clenbuterol / Q000008:administration & dosage* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004983:Ethanolamines / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male
D004983:Ethanolamines; D002976:Clenbuterol