Randomized trial of modafinil as a treatment for the excessive daytime somnolence of narcolepsy

OBJECTIVE: This is one of two separate clinical trials to evaluate the efficacy and safety of modafinil, a novel wake-promoting agent, in patients with excessive daytime sleepiness (EDS) associated with narcolepsy. METHODS: In this 9-week, randomized, placebo-controlled, double-blind, 21-center clinical trial, patients were randomized to receive fixed daily doses of modafinil 200 mg, modafinil 400 mg, or placebo. A placebo-controlled, 2-week treatment discontinuation phase was included to evaluate the effects of withdrawal on patients who had been receiving modafinil. A total of 271 patients who were naive to modafinil received study medication in the 9-week trial and 240 patients received study medication in the discontinuation phase. RESULTS: Treatment with modafinil resulted in significant improvement in two objective measures of EDS: the Multiple Sleep Latency Test and the Maintenance of Wakefulness Test. Additionally, patient self-assessment of sleepiness was significantly improved, as measured by the Epworth Sleepiness Scale, and level of illness was significantly reduced on the independent clinician assessment, the Clinical Global Impression of Change. Nighttime sleep, monitored by nocturnal polysomnography, was not adversely effected with modafinil treatment compared with placebo treatment. The most frequent adverse experience was headache, which was not significantly greater for modafinil than placebo. During treatment discontinuation, individuals who had been receiving modafinil experienced a return of their EDS to baseline levels. During treatment discontinuation, patients did not experience symptoms associated with amphetamine withdrawal syndrome. For up to 9 weeks of daily use there was no evidence for the development of dependence at the dose levels studied. CONCLUSION: The data indicate that modafinil has an excellent safety profile and is very well tolerated. Modafinil is an effective treatment for excessive daytime sleepiness in narcolepsy and shows continued efficacy with up to 9 weeks of daily use.