Theophylline and aerosolized terbutaline in the treatment of bronchial asthma. Double-blind comparison of optimal doses.

The bronchodilator response to aerosolized terbutaline and optimal doses of theophylline, given singly and in combination, was studied in ten patients with perennial asthma. Optimal doses of theophylline were determined (mean peak theophylline level of 20.9 micrograms/ml). Patients then received this theophylline dose plus 500 micrograms aerosolized terbutaline by metered-dose nebulizer qid for one week. Placebo was then substituted for one of the active agents for two weeks, followed by both active agents again for one week, and finally, placebo substituted for the second agent for a two-week period. The therapeutic response was determined by measurement of peak expiratory flow rate four times daily at different intervals following medication and the patient's subjective assessment of each period. The combination was found to be superior to either theophylline or terbutaline alone (P < .05). Theophylline alone and aerosolized terbutaline alone were equally effective. No side effects were encountered with any of the treatment regimens.