Solriamfetol (formerly JZP-110), a dopamine/norepinephrine reuptake inhibitor, is approved in the US to improve wakefulness in adults with excessive daytime sleepiness associated with narcolepsy (75-150 mg/d) or obstructive sleep apnea (37.5-150 mg/d). In a randomized, double-blind, placebo-controlled trial in participants with narcolepsy, effects of solriamfetol on functional status, health-related quality of life (HRQoL), and work productivity were evaluated.Participants with narcolepsy (N = 239) were randomized to solriamfetol 75, 150, or 300 mg, or placebo for 12 weeks. Outcome measures included the Functional Outcomes of Sleep Questionnaire short version (FOSQ-10), 36-Item Short Form Health Survey version 2 (SF-36v2), and Work Productivity and Activity Impairment questionnaire for Specific Health Problem (WPAI:SHP). A mixed-effects model with repeated measures was used for comparisons vs placebo.At week 12, solriamfetol increased FOSQ-10 total score, with greatest mean difference from placebo (95% CI) at 300 mg (1.45 [0.31, 2.59]). On SF-36v2, improvements vs placebo were observed in physical component summary scores (300 mg: 2.22 [0.04, 4.41]) and subscales of role physical, general health, and vitality. On WPAI:SHP, solriamfetol 150 mg reduced overall work impairment vs placebo (-15.5 [-29.52, -1.47]), and 150 and 300 mg reduced activity impairment vs placebo (-10.05 [-19.48, -0.62] and -13.49 [-23.19, -3.78], respectively). Most treatment-emergent adverse events (TEAEs) were mild or moderate in severity. Common TEAEs were headache, nausea, decreased appetite, nasopharyngitis, dry mouth, and anxiety.Solriamfetol improved measures of functional status, HRQoL, and work productivity, particularly at the 150- and 300-mg doses. Most TEAEs were mild to moderate.ClinicalTrials.gov identifier NCT02348593, EudraCT number 2014-005487-15.