The cardiorespiratory effects of oral terbutaline and an ephedrine-theophylline-phenobarbital combination: comparison in patients with chronic obstructive ventilatory disorders.

Initial responses and changes in baseline after two-week treatments with a sustained release ephedrine-theophylline-phenobarbital (ETP) tablet and terbutaline tablets were studied in a double-blind crossover trial for 20 patients with chronic obstructive lung diseases. At the 12th hour after the second dose of terbutaline both drugs were active with mean changes at four and eight hours favoring ETP. After two weeks of treatment improvement in baseline functions also favored the combination. Although terbutaline was effective, ETP was the superior bronchodilator with a later peak response, greater magnitude of improvement and longer duration of action. The differences suggest the advantage of reinforcing ephedrine with a methylxanthine derivative.