Theophylline is effective in the treatment of
central apneas and periodic breathing. In
obstructive sleep apnea syndrome (OSAS), results of pharmacological monotherapy with
theophylline are inconsistent. The present study investigates whether additional
theophylline in patients with OSAS and
continuous positive airway pressure (CPAP)
therapy might improve ventilation, lower effective CPAP pressure levels or affect sleep architecture. Patients with mild to moderate OSAS (mean
apnea index [AI] 12.8+/-11.7) and CPAP
therapy (Autoset system; n=16, all male) received either 900 mg of oral sustained-release
theophylline (T) or placebo (P) on two separate nights, 3 days apart, using a randomized double-blind crossover study design. There was no change in AI (T: 0.7+/-1.4 vs. P: 0.7+/-0.6/h; P=0.3) or
apnea-hypopnea index (AHI; T: 4.3+/-3.3 vs. P: 4.5+/-3.7/h; P=0.84) when
theophylline was added to CPAP
therapy. We observed no difference in mean CPAP pressure (T: 6.9+/-2.1 vs. P: 6.7+/-1.9 cm H2O; P=0.7) or 95% pressure percentiles (T: 9.7+/-2.7 vs. P: 9.3+/-2.1cm H2O; P=0.3) when nights with
theophylline were compared to placebo nights.
Theophylline reduced significantly total sleep time (T: 290.6+/-58.9 vs. P: 338.0+/-40.1 min; P=0.02) and thus sleep efficiency (SE; T: 70.5+/-14.9%, P: 82.0+/-70.5%; P=0.005). Rapid eye movement and slow wave sleep were not affected. Oral
theophylline did not show any additional effects on ventilation parameters or pressures in patients with mild to moderate OSAS once CPAP
therapy has been successfully installed. SE was reduced with
theophylline with unchanged sleep architecture. The role of oral
theophylline may be in patients with predominately
central apneas not eligible for ventilation
therapy or severe cases.