title: The bronchodilator effect of caffeine in adult asthmatics.
abstract: Caffeine has been reported to result in bronchodilation in asthmatic children. Our study was designed to assess the effect of caffeine on pulmonary function in adults with asthma. We studied 8 patients: 4 men and 4 women with previously documented airway reactivity. A randomized, double-blind cross-over was used. The patients received either placebo or 5 mg/kg of caffeine in solution orally, and FEV1, FVC, FEF25-75, Vmax25 and blood for caffeine concentrations were taken at several time points for as long as 8 h after the drink.
  
  
  RESULTS
  there was a significant difference between caffeine and placebo for percent change in FEV1 with peak change at 1.5 h. There was also a significant difference for percent change in FEF25-75 with peak occurring at 4 h. Percent change in Vmax25 was significantly different at 3.0 h only. Peak caffeine concentration of 8.7 +/- 1.7 micrograms/ml occurred at 1 h. The data indicate that caffeine at a dose of 5 mg/kg can produce significant percentage improvement in FEV1, FEF25-75, and Vmax25 in adult asthmatics.
mesh_terms: D000328:Adult; D001249:Asthma / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D001993:Bronchodilator Agents; D002110:Caffeine / Q000097:blood / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D005541:Forced Expiratory Volume; D006801:Humans; D011897:Random Allocation; D013997:Time Factors; D014797:Vital Capacity / Q000187:drug effects
chemical_list: D001993:Bronchodilator Agents; D002110:Caffeine