EFFECTS OF REPEATED ADMINISTRATION OF ZOLPIDEM ON SLEEP, DIURNAL AND NOCTURNAL RESPIRATORY-FUNCTION, VIGILANCE, AND PHYSICAL PERFORMANCE INPATIENTS WITH COPD

Study objective: To assess the effects of repeated 10-mg oral doses of zolpidem on diurnal and nocturnal respiratory function, as wed as on diurnal vigilance and physical performance in COPD patients with disor dered sleep. Design: Prospective single-blind placebo-controlled clini cal study. Setting: Outpatients of a respiratory medicine department. Patients and methods: Patients with stable COPD were enrolled for 10 d ays (DO to D10), ie, 9 consecutive nights (NI to N9). They received pl acebo on N1 and N9 and zolpidem, 10 mg, from N2 to N8. Measurements: T he following parameters were measured: nocturnal polysomnographic reco rdings with respiratory signals and arterial blood gas values on retir ing and awakening on NO, N1, N2, N8, and N9; subjective evaluation of the quality of sleep and of diurnal vigilance by visual analog scales every clay from DO to D10; pulmonary function test, central control of breathing, and walking test on DO and D9; biological laboratory tests and theophylline level on DO and D8. Results: Ten COPD patients (PaO2 =72.7+/-7.6 mm Hg; PaCO2=47.7+/-5.4 mm Hg; FEV(1)=0.84+/-0.3 L; FEV(1) /vital capacity=42.5+/-12.3%), 50.8+/-8.3 years old, were studied. Com pared with placebo, no significant change was found for the various sl eep architecture parameters, except an increase in the duration of sta ge 2 during the D8/N8 night (p<0.05). In contrast, the autoevaluation score for the quality of sleep was significantly improved during the D 6/N6 night relative to that with placebo (p<0.05), with no change in t he other subjective criteria. No variable of the nocturnal respiratory parameters, pulmonary function test, central control of breathing, an d physical performance was altered by zolpidem. Arterial blood gas val ues on awakening were not altered. Clinical and biological tolerance o f zolpidem was correct with no significant variation of the theophylli ne level. Conclusion: This study shows that repeated 10-mg oral doses of zolpidem Juring 8 days does not impair nocturnal respiratory and sl eep architecture parameters or diurnal pulmonary function tests, centr al control of breathing, and physical performances in patients with st able COPD.