Sustained-Release Theophylline Reduces Dyspnea in Nonreversible Obstructive Airway Disease1–4

Although orally administered theophylline has been prescribed widely in patients with nonreversible airway obstruction, symptomatic benefit has not been established. To assess the effects of orally administered theophylline on dyspnea, we performed a randomized, double-blind, crossover, placebo-theophylline clinical trial in 12 ambulatory male patients with moderate to severe nonreversible airway obstruction. Dyspnea was rated using 2 clinical indexes based on 3 components affecting breathlessness: functional impairment, magnitude of task that evokes dyspnea, and the associated magnitude of effort. Dyspnea and physiologic parameters were measured on 4 occasions: at baseline, 4 wk after initial treatment, a second baseline after a 2-wk washout period, and 4 wk after the second medication. For the 12 patients, mean age (± SD) was 60 ± 7 yr, forced expiratory volume in one second was 1.36 ± 0.67 L (mean, 40% of predicted), and arterial oxygen tension was 71 ± 10 mmHg. During the treatment phase, all patients...