The effect of controlled-release salbutamol on sleep and nocturnal oxygenation in patients with asthma and chronic obstructive pulmonary disease.

Patients with asthma or chronic obstructive pulmonary disease (COPD) may have falls in oxygen saturation at night. We have investigated the effect of a long acting beta agonist (salbutamol CR) on nocturnal oxygen saturation (SaO2) in asthma and COPD. Eleven asthmatic and 14 COPD patients in stable condition were randomly allocated to 8 mg salbutamol CR or placebo twice daily in a double-blind, cross-over study. FEV1 at entry was 71.5% predicted in the asthmatic patients and 36% predicted in the COPD group. Each treatment period lasted 7 days, at the end of which measurements of ventilatory function and detailed sleep studies were performed. There was a significant improvement in morning FEV1 in the asthmatic patients when on active treatment and a small, but non-significant improvement in the COPD group. Sleep architecture and oxygenation were similar on placebo and on active treatment in both groups. We conclude that salbutamol CR has no significant effect on nocturnal oxygenation or sleep pattern in patients with mild asthma or moderately severe COPD.