Clinical Trial Demonstrates Effectiveness of Solriamfetol in Improving Alertness for Early Morning Shift Workers
The biological cost of the modern 24-hour economy is often paid by those who rise while the rest of the world is still in deep sleep. While much of the scientific literature on sleep disruption has historically focused on overnight "graveyard" shifts, a significant portion of the global workforce operates on early-morning schedules, starting their duties between 3 a.m. and 7 a.m. A groundbreaking clinical trial led by researchers at Mass General Brigham has revealed that solriamfetol, a wake-promoting medication, significantly improves alertness and functional capacity in these early-morning workers. The study, published in NEJM Evidence, marks the first time a clinical trial has specifically targeted this demographic, addressing a critical gap in occupational health and sleep medicine.
Shift work disorder (SWD) is a chronic condition characterized by excessive sleepiness during work hours and insomnia when the individual attempts to sleep during the day. For early-morning workers, the challenge is twofold: they must perform high-stakes tasks during the circadian trough—the period when the body’s internal clock is most insistent on sleep—and they must attempt to rest when the environment is becoming noisy and bright. The findings from Mass General Brigham suggest that solriamfetol, currently marketed under the name Sunosi, provides a meaningful therapeutic intervention for those struggling with the debilitating fatigue associated with these schedules.
The Invisible Struggle of the Early-Morning Workforce
Despite the prevalence of early-morning shifts in sectors such as transportation, healthcare, logistics, and emergency services, these workers are frequently overlooked in sleep research. Many do not even identify as "shift workers," instead viewing their 4 a.m. starts as simply an "early day." However, the biological reality is far more complex. The human brain is evolutionarily programmed to be at its lowest level of alertness in the hours just before dawn.
Dr. Kirsi-Marja Zitting, an investigator with the Division of Sleep and Circadian Medicine at Mass General Brigham and the study’s first author, noted that these workers face a "double burden." They are forced to operate when their biological drive for sleep is at its peak, and they often find it impossible to compensate for that lost sleep later in the day due to the body’s natural arousal signals that kick in during the daylight hours. This misalignment leads to a persistent state of sleep debt, which can have catastrophic consequences for both personal health and public safety.
Study Design and Methodology
The clinical trial was designed to evaluate the efficacy and safety of solriamfetol in a controlled yet representative environment. The researchers enrolled 78 adults diagnosed with shift work disorder who were consistently working early-morning shifts. The participants were randomized into two groups: one receiving a daily dose of solriamfetol and the other receiving a placebo over a four-week period.
To measure the drug’s effectiveness, the team utilized rigorous assessment tools, including simulated work environments where participants’ ability to remain awake was tested under low-stimulation conditions. This is a critical metric, as many workplace accidents occur during monotonous tasks where the drive for sleep becomes overwhelming. Researchers also monitored daily functioning through self-reports and clinical evaluations, providing a comprehensive view of how the medication influenced the participants’ lives both on and off the clock.
Solriamfetol works as a dual norepinephrine and dopamine reuptake inhibitor (DNRI). Unlike traditional stimulants that may cause a "crash" or significantly interfere with subsequent sleep, solriamfetol has shown a profile that promotes sustained wakefulness throughout a standard eight-hour shift without the same level of disruption to the following sleep cycle—a crucial factor for workers who need to rest immediately after their shift ends.
Key Findings: Alertness and Functional Improvement
The results of the four-week trial were definitive. Participants who took solriamfetol demonstrated a statistically significant increase in their ability to stay awake compared to the placebo group. On average, those treated with the medication could remain alert for longer durations during their simulated shifts, and they reported feeling substantially less sleepy throughout the day.
Beyond the objective measures of wakefulness, the study highlighted improvements in "real-world" functioning. Both the participants and the clinicians overseeing the trial noted marked enhancements in work performance and the ability to manage daily responsibilities. Dr. Charles A. Czeisler, chief of the Division of Sleep and Circadian Medicine at Mass General Brigham and the study’s senior author, emphasized that the improvements were "clinically meaningful."
"These workers were able to stay awake and alert throughout a full eight-hour shift," Czeisler stated. "This has real implications for performance, safety, and quality of life. Shift workers are essential to how our society functions, yet they often pay a hidden biological cost. This study shows we can do better for them."
The Broader Implications for Occupational Safety
The implications of untreated shift work disorder extend far beyond individual fatigue. The condition is a known risk factor for workplace injuries and motor vehicle accidents, particularly during the commute home when the "post-shift" exhaustion hits. In industries such as long-haul trucking or aviation, even a momentary lapse in concentration can result in loss of life.
Data from the National Highway Traffic Safety Administration (NHTSA) suggests that drowsy driving is responsible for thousands of fatalities annually, with shift workers being among the highest-risk groups. By providing a pharmacological tool that effectively bridges the gap between the circadian rhythm and work requirements, solriamfetol could potentially reduce the incidence of these accidents.
Furthermore, the economic impact of SWD is substantial. Reduced productivity, increased absenteeism, and higher healthcare costs associated with the long-term effects of sleep deprivation—such as cardiovascular disease, diabetes, and mental health disorders—place a heavy burden on the economy. Improving the wakefulness of this workforce is not just a matter of clinical health; it is a matter of economic and structural stability.
A Chronology of Treatment for Shift Work Disorder
The treatment of shift work disorder has evolved slowly over the last several decades. Historically, workers relied heavily on caffeine and, in some cases, off-label use of amphetamines to stay awake. In the late 1990s and early 2000s, the introduction of modafinil and armodafinil provided the first FDA-approved options specifically for sleepiness associated with SWD.
However, these treatments were primarily tested on night-shift workers. The early-morning cohort remained largely ignored until this recent trial. Solriamfetol was approved by the FDA in 2019 for the treatment of excessive daytime sleepiness associated with narcolepsy and obstructive sleep apnea. Its transition into the realm of shift work disorder represents a logical progression in sleep medicine, recognizing that the mechanism of sleepiness in SWD shares commonalities with other sleep disorders.
Future Research and Long-Term Considerations
While the results of the Mass General Brigham study are promising, the researchers were careful to note the limitations of the trial. The four-week duration provides a snapshot of the drug’s efficacy but does not account for long-term physiological effects or the potential for building a tolerance. Additionally, the study focused on otherwise healthy adults, meaning more research is required to understand how the medication interacts with other chronic health conditions common among shift workers.
The research team is already moving forward with a follow-up clinical trial that will focus on overnight shift workers. This broader scope is intended to provide the comprehensive data necessary for regulatory bodies to consider expanding the approved use of solriamfetol to include all forms of shift work disorder.
Conclusion: Supporting the Essential Workforce
The study underscores a shifting perspective in occupational medicine: the recognition that sleep health is a fundamental pillar of workplace safety. For the millions of people who start their engines, open their clinics, or begin their factory lines at 4 a.m., the struggle against their own biology is a daily reality.
The validation of solriamfetol as an effective treatment for early-morning shift workers offers a path toward a safer and more productive environment. As society continues to rely on 24-hour operations, the development of targeted therapies that respect the complexity of the human circadian system will remain a priority for researchers and policymakers alike. The work of Czeisler, Zitting, and their colleagues at Mass General Brigham provides a vital blueprint for addressing the "hidden biological cost" of the modern world.
