Falliers C J, Cato A E, Harris J R
J Int Med Res. 1978;6(4):326-36. doi: 10.1177/030006057800600411.
Various pulmonary function changes were determined in twenty paediatric patients after a single oral dose of theophylline, ephedrine, or their combination in a double-blind crossover study. The possible contributions of guaifenesin and butabarbital, components of some formulations in clinical use, were also examined. Bronchodilatory efficacy in decreasing order, when compared to placebo, was observed for theophylline-ephedrine and theophylline (nearly comparable), and for ephedrine-butabarbital and ephedrine (nearly comparable). Butabarbital and guaifenesin did not enhance or decrease bronchodilatory effect. Adverse reactions appeared to be more frequently related to ephedrine intake, although no serious reactions were noted.