Effect of zolpidem on the efficacy of continuous positive airway pressure as treatment for obstructive sleep apnea

STUDY OBJECTIVE: Assess the effect of the hypnotic zolpidem on the efficacy of nasal continuous positive airway pressure for treatment of Obstructive Sleep Apnea. DESIGN: Randomized double blind placebo controlled, cross-over study. SETTING: Veterans Administration Medical Center. PATIENTS: 16 patients with severe obstructive sleep apnea (apnea+ hypopnea index > 30/hr), on CPAP therapy for at least 6 months. INTERVENTION: Three sleep studies were performed over three consecutive weeks. On night one the pressure level required to prevent apnea, hypopnea, and snoring was determined. On the second and third study nights, either placebo (P) or 10 mg of zolpidem (Z) was given (random order) and subjects slept on the CPAP level determined on the first night. MEASUREMENTS: Sleep architecture, apnea + hypopnea index, arterial oxygen saturation. RESULTS: The sleep architecture was similar on the placebo and zolpidem nights except for a decrease in the sleep latency ( P: 23.5 +/- 4.7; Z: 13.1 +/- 3.3 minutes, P < 0.02) and a small decrease in the arousal index (P < 0.03) on zolpidem nights. The was no significant difference between placebo and zolpidem nights in the apnea + hypopnea index (P: 4.8 +/- 1.4 versus Z : 2.7 +/- 0.47 events/hour), oxygen desaturation index (1.46 +/- 0.53 versus 0.81 +/- 0.29 desaturations/hour), or the lowest SaO2 (91.4 +/- 0.6 versus 91.0 +/- 0.7%). CONCLUSIONS: Acute administration of zolpidem 10 mg does not impair the efficacy of an effective level of CPAP in patients with severe obstructive sleep apnea.