Efficacy was assessed using the Maintenance of Wakefulness Test (MWT) (six 20-min subtests across the day), the Clinical Global Impression of Change (CGI-C), subjective measures of sleepiness (Epworth Sleepiness Scale), patient diaries, and evaluations of cognitive performance (Cognitive Drug Research) and fatigue (Brief Fatigue Inventory).
Provigil significantly increased MWT mean sleep latency (at 0900-1500) compared with placebo. The mean change from baseline at final visit for Provigil was an increase of 1.3, 2.6, and 1.9 min in the 150-mg, 250-mg, and combined groups, respectively, compared with a decrease of 1.9 min for placebo (p < 0.01 for all three comparisons).
Mean late-day MWT latency (1500-1900) was also significantly improved (difference of Provigil combined group relative to placebo at final visit: 2.8 min, p = 0.0358). The proportions of patients who showed at least minimal improvement in the CGIC rating from baseline to final visit in the Provigil 150-mg, 250-mg, and combined groups were 69%, 73%, and 71%, respectively, compared with 33% for placebo (p < 0.0001). Both doses were associated with statistically significant improvements in memory, attention, and fatigue (p < 0.05). The most common adverse events in patients receiving Provigil were headache, nausea, and dizziness.
Provigil significantly improved ability to sustain wakefulness throughout the day in patients with narcolepsy. Provigil also significantly improved overall clinical condition, memory, attention, and fatigue when compared with placebo.