An evaluative study of the short-term effects of once-daily, sustained-release theophylline on sleep in nocturnal asthmatics
Richardt, D.; Driver, H.S.
South African Medical Journal 86(7): 803-804
1996
ISSN/ISBN: 0256-9574 PMID: 8764904 Document Number: 463526
Objective: To examine the effects of once-daily, sustained release theophylline on sleep patterns in nocturnal asthmatics. Design: Double-blind, randomised, cross-over, placebo-controlled trial over 22 days. Seven-day period to establish therapeutic levels of theophylline (11.8 +- 3 mg/1); 8-day cross-over period of 4 days' placebo or theophylline; 7-day baseline period. Electrophysiological sleep patterns, overnight bronchoconstriction and arterial O-2 saturation monitored on nights 7, 11 and 15. Setting: Sleep Laboratory, Medical School, University of the Witwatersrand. Patients: Twelve volunteers who met the criteria for asthma, had previously used theophylline, were clinically stable and had a history of nocturnal awakenings caused by asthma were enrolled. Outcome measures: Sleep-onset latency (SOL), within sleep wakefulness (WSW), rapid eye movement sleep (REM), slow-wave sleep (SWS), peak expiratory flow rate (PEFR) and arterial oxygen saturation. Results. SOL increased on theophylline -12 minutes (range 7-9 minutes) compared with placebo -6 minutes (range 3-11 minutes); WSW increased from 33 minutes (range 17-66 minutes) on placebo to 72 minutes (range 35-150 minutes) on theophylline. REM sleep was unaltered. SWS decreased in 10-12 patients, but this difference was not significant. Early morning PEFR was significantly better on theophylline in all study limbs. Conclusion: Our findings show that while once-daily, sustained-release theophylline improves bronchodilation in nocturnal asthmatics, it increases nocturnal wakefulness and decreases sleep efficiency during short-term treatment. This may, however, not be a long-term effect.