Sleep disturbances in asthma: theophylline versus enprofylline

A double-blind cross-over study was performed on 22 asthmatic patients receiving maintenance treatment with theophylline who, in a previous study, had reported sleep problems. In one of two three-week periods the theophylline medication was replaced by an equipotent dose of slow-release enprofylline. Analysis of sleep questionnaires answered after each treatment period, and sleep diaries filled in throughout the study, showed no significant differences in the quality of sleep between the treatments. Peak expiratory flow (PEF) in the morning did not differ between the treatment periods, but mean PEF in the evening was slightly higher (20 l/min) during theophylline treatment. It was concluded that replacement of theophylline by enprofylline did not improve the quality of sleep subjectively in this group of theophylline treated asthmatics. The results suggest that adenosine receptor antagonism may not be a significant cause of sleep disturbances in asthmatic patients who are receiving theophylline as maintenance treatment.