bronchodilator effects of terbutaline and aminophylline alone and in combination in asthmatic patients in 17 patients with moderate to severe asthma we compared acute bronchodilator effects of the following drugs or drug combinations using a doubleblind crossover design terbutaline 5 aminophyline 400 terbutaline 5 plus aminophyline 400 terbutaline 25 aminophylline 200 terbutaline 25 plus aminophyline 200 mg and placebo the higher doses of terbutaline and aminophylline alone produced comparable bronchodilation and similarly frequent adverse side effects low doses of each drug also had comparable effects the highdose combination produced significantly p less than 005 greater bronchodilatation than either drug alone the low dose combination had bronchodilator effects comparable to those produced by the higher dose of either drug alone these findings suggest therapeutic advantages in combining high doses of theophylline and an oral beta adrenergic agonist terbutaline in asthma not well controlled on high doses of either drug alone and in combining these drugs in lower doses in patients experiencing intolerable side effects from a high dose of either drug