Twelve patients with documented obstructive sleep apnea

were enrolled in a double-blind placebo controlled crossover trial of oral theophylline, (Uniphyllin) 800 mg, taken at night for four weeks. Overnight polysomnography, using standard techniques, was perfisemed at the end of each treatment period. The total number of apneas (A) and hypopneas (H) decreased significantly while receiving the ophylline compared to placebo, from 398(69), mean (SEM), to 283(72), p4 percent were less with theophylline treatment (pO.O2), but mean overnight Sa02 was unchanged. We conclude that theophylline may be beneficial in patients with OSA, but part ofthe improve ment is due to a deterioration in sleep quality. (Cheat 1992; 101:753-57)