A randomized trial evaluating the effectiveness of sodium oxybate therapy on quality of life in narcolepsy

To evaluate the efficacy of sodium oxybate versus placebo to improve quality of life in patients with narcolepsy.

A multicenter, double-blind, placebo-controlled trial.

Outpatient facility of 42 sleep centers in the United States, Canada, and Europe.

Study participants were 285 patients with narcolepsy, 16 to 75 years of age, with a median Epworth Sleepiness Scale score of 18, a Maintenance of Wakefulness Test sleep latency of 9.56 minutes, and experiencing symptoms of narcolepsy, including cataplexy and excessive daytime sleepiness with recurrent sleep episodes almost daily for at least 3 months at the time of enrollment.

Subjects were gradually withdrawn from narcolepsy medications used for cataplexy, including antidepressants. Subsequently, participants were randomly assigned to receive 4.5, 6.0, or 9.0 g per day of sodium oxybate or placebo taken in two equally divided doses upon retiring to bed and again 2.5 to 4 hours later for 4 weeks during the stable dosing phase.

The change in quality of life following the administration of sodium oxybate was measured with the Functional Outcomes of Sleep Questionnaire. The nightly administration of sodium oxybate produced significant dose-related improvements in the Total Functional Outcomes of Sleep Questionnaire score, as well as in the Activity Level, General Productivity, Vigilance, and Social Outcomes subscales.

The nocturnal administration of sodium oxybate in patients with narcolepsy was associated with statistically significant and clinically relevant improvements in functional status, an important component of quality of life.