Treatment of chronic obstructive pulmonary disease with orally administered theophylline. A double-blind, controlled study.

Theophylline is commonly prescribed for chronic obstructive pulmonary disease (COPD), although controlled studies do not exist to support this use. We administered theophylline and placebo orally to 40 ambulatory COPD patients in a double-blind, crossover manner. Pulmonary function tests were conducted before and after isoproterenol nebulization on the final day of each four-week study period. Theophylline therapy produced small, but significant, increases over placebo in mean values. However, only the forced expiratory volume in 1 s was "improved," according to published criteria. There were no significant differences in subjective effects between treatment periods. Six patients were identified as "responders"; responder status could be predicted on the basis of improvement in flow rates after isoproterenol nebulization. Theophylline therapy is not beneficial to most COPD patients, and potential responders should be given carefully monitored therapeutic trials rather than arbitrarily being given maintenance therapy.