Solriamfetol for OSA Sleepiness: Does It Disrupt Night Sleep?

THE PROTOHUMAN PERSPECTIVE#

Sleep architecture is the scaffolding on which cognitive performance, metabolic function, and cellular repair are built. For the estimated one billion people globally living with obstructive sleep apnea, the cruel irony has always been this: the disorder fragments your nights, and the resulting daytime sleepiness fragments everything else — decision-making, autophagy cycling, HRV stability, even NAD+ synthesis pathways that depend on consolidated deep sleep windows. Wake-promoting agents were supposed to fix the daytime half of that equation, but clinicians and patients alike have hesitated. The fear — not unreasonable — was that chemically forcing wakefulness during the day might cannibalize sleep quality at night. Wang et al.'s new phase 3 data from Chinese OSA-EDS patients directly addresses that fear, and the answer matters for anyone optimizing their sleep-wake architecture as a performance lever. If a drug can sharpen the day without degrading the night, it changes the risk calculus entirely.

THE SCIENCE#

What Is Solriamfetol, and Why Does It Matter?#

Solriamfetol is a selective dopamine and norepinephrine reuptake inhibitor (DNRI) approved in the United States and the European Union for treating excessive daytime sleepiness (EDS) associated with obstructive sleep apnea (OSA) and narcolepsy ^[1][6]. Unlike traditional stimulants, its mechanism is narrower — it selectively binds dopamine and norepinephrine transporters without significant serotonergic activity, which theoretically reduces both abuse potential and the kind of sympathetic overdrive that might wreck sleep architecture. The FDA and EMA approvals were built on the TONES trial series (TONES 3–5), which demonstrated consistent reductions in Epworth Sleepiness Scale (ESS) scores and improvements in Maintenance Wakefulness Test (MWT) latency ^[1]. Real-world data from 665 US patients showed high adherence (mean proportion of days covered = 0.9), with 79.2% achieving a PDC ≥ 0.8 ^[5].

But here's where it gets complicated. Efficacy for daytime wakefulness was never the real question. The question was whether you'd pay for it at night.

The Chinese Phase 3 Trial: Sleep Architecture Under the Microscope#

Wang et al. (2026) conducted an exploratory analysis within a 12-week, randomized, double-blind, placebo-controlled, multicenter phase 3 trial involving 357 Chinese patients with OSA-EDS ^[1]. Participants were randomized 1:1 to receive either solriamfetol 150 mg or placebo once daily, taken in the morning. The coprimary endpoints were changes in MWT mean sleep latency and ESS scores at week 12, but the data I find most valuable are the exploratory polysomnography (PSG) endpoints — total sleep time (TST), wakefulness after sleep onset (WASO), mean oxygen saturation (SaO₂), minimum SaO₂, apnea index, and apnea-hypopnea index (AHI) — measured at weeks 2, 5, and 12.

The headline result: no clinically significant or consistent changes in PSG parameters were observed compared with placebo. Morning solriamfetol administration did not meaningfully alter nocturnal sleep architecture. There were isolated statistically significant findings — N1 sleep stage showed a change at week 2 (P = 0.0022), and N3 at week 5 (P = 0.0212) — but these were not sustained across timepoints, and the investigators appropriately flagged them as hypothesis-generating rather than confirmatory.

I want to be precise about what this means and what it doesn't. These PSG parameters were unadjusted, exploratory endpoints. The trial was powered for the coprimary efficacy outcomes, not for detecting subtle sleep architecture changes. A null finding in an underpowered exploratory analysis is not the same as proof of safety. It's reassuring — genuinely — but the honest framing is that solriamfetol appears not to disrupt nocturnal sleep at 150 mg when taken in the morning.

The Cognitive Dimension: SHARP Trial Data#

— Actually, I want to shift gears here because the sleep story alone undersells what's happening with this compound.

The SHARP trial (Van Dongen et al., 2025), published in CHEST, was a phase IV randomized, double-blind, placebo-controlled crossover study that assessed solriamfetol's effects on cognitive function in 59 patients with OSA-EDS and cognitive impairment ^[2]. Solriamfetol significantly improved Digit Symbol Substitution Test (DSST) scores from the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) compared with placebo (P = .009), with an effect size of Cohen's d = 0.37. Patients also reported subjective improvement on the Patient Global Impression of Severity (PGI-S) scale.

A Cohen's d of 0.37 is a small-to-medium effect. I'm not sure this matters clinically for everyone, but for a subset of patients — those whose OSA-related cognitive fog is actively impairing their work or driving safety — even a modest gain in processing speed is meaningful. The problem with this trial is the sample size: 59 participants in a crossover design. I'd want to see this replicated in a larger parallel-arm trial before anchoring any strong claims about cognitive rescue.

Real-World Adherence and Outcomes#

Two real-world studies fill in the gaps that controlled trials can't. The US MarketScan analysis (Zhao et al., 2025) found that among 665 OSA patients initiating solriamfetol, significant reductions were observed in fatigue/tiredness (16.5% to 11.6%), hypersomnia diagnoses (57.3% to 48.3%), insomnia (18.8% to 15.8%), and sleep disturbance (12.5% to 8.7%), all at P < 0.05 ^[5]. The German SURWEY study (Winter et al., 2025) reported that most physicians initiated solriamfetol at 37.5 mg/day, with titration typically completed within 2 weeks, and ESS scores improved meaningfully from a baseline mean of 16.0 ^[6].

The catch, though: the US study was funded by Axsome Therapeutics, which acquired solriamfetol rights from Jazz Pharmaceuticals. Industry sponsorship doesn't invalidate the data, but it means I read the symptom-reduction claims through a tighter lens. Claims data also capture diagnosis codes, not patient-reported experiences — a reduction in "insomnia" diagnoses post-index doesn't necessarily mean patients are sleeping better. It means clinicians stopped coding insomnia.

COMPARISON TABLE#

THE PROTOCOL#

For patients with diagnosed OSA-EDS considering solriamfetol, based on the current clinical evidence and prescribing guidelines:

Step 1: Confirm the diagnosis and establish baseline metrics. Before initiating any wake-promoting agent, ensure you have a formal OSA diagnosis via polysomnography or home sleep test. Record your baseline ESS score, and if possible, your AHI and oxygen saturation data. This is the foundation — don't skip it.

Step 2: Optimize primary OSA therapy first. Solriamfetol is an adjunct, not a replacement for CPAP, oral appliance therapy, or positional therapy. Real-world data from the SURWEY study shows that most patients were already on primary OSA treatment when solriamfetol was initiated ^[6]. Residual EDS despite adequate CPAP adherence is the primary clinical indication.

Step 3: Initiate at 37.5 mg/day, taken within 15 minutes of waking. The German SURWEY data and prescribing guidelines both support starting at 37.5 mg ^[6]. Take it in the morning — the Wang et al. trial specifically evaluated morning administration and found no disruption to nocturnal sleep at 150 mg ^[1]. Avoid dosing after noon.

Step 4: Titrate based on response and tolerability over 2–4 weeks. Most physicians in the SURWEY study completed titration within 2 weeks, moving from 37.5 mg to 75 mg, and then to 150 mg if needed ^[6]. Monitor for common side effects: headache, nausea, decreased appetite, and anxiety. Blood pressure monitoring is recommended, as norepinephrine reuptake inhibition can modestly elevate blood pressure.

Step 5: Reassess at 12 weeks with repeat ESS and, if available, PSG. The phase 3 trial's endpoint was at week 12, and this timeframe captures both the therapeutic plateau and the confirmation that nocturnal sleep parameters remain stable ^[1]. If ESS has not improved by at least 3 points, discuss alternatives with your clinician.

Step 6: Track subjective cognitive function. Based on the SHARP trial data, solriamfetol may improve processing speed and cognitive clarity ^[2]. Use a simple daily log — even a 1–10 mental sharpness rating — to track whether the cognitive benefit is present for you personally.

Step 7: Do not discontinue CPAP. This bears repeating. Solriamfetol does not treat the apnea itself. The Wang et al. data showed no changes in AHI or oxygen saturation — which is actually what you want. It means the drug isn't masking worsening airway obstruction ^[1].

What is solriamfetol, and how does it differ from modafinil?#

Solriamfetol is a dopamine and norepinephrine reuptake inhibitor specifically approved for excessive daytime sleepiness in OSA and narcolepsy. Unlike modafinil, whose mechanism remains somewhat unclear and involves weak dopamine transporter binding plus broader neurochemical effects, solriamfetol has a defined dual reuptake inhibition profile. In practice, this means a more predictable dose-response curve, though it also means it's still brand-name only and significantly more expensive than generic modafinil.

Does solriamfetol affect nighttime sleep quality?#

Based on the Wang et al. phase 3 trial involving 357 Chinese patients, morning administration of solriamfetol 150 mg did not produce clinically significant or consistent changes in polysomnography parameters compared with placebo ^[1]. Total sleep time, wakefulness after sleep onset, and respiratory parameters all remained stable. That said, these were exploratory endpoints — I'd characterize the evidence as "reassuring but not definitive."

Who should consider solriamfetol for OSA-related sleepiness?#

The primary candidates are adults with diagnosed OSA who experience persistent excessive daytime sleepiness despite adequate primary therapy (typically CPAP with good adherence). The real-world US data showed that about 55% of patients initiating solriamfetol had prior experience with other wake-promoting agents or stimulants ^[5], suggesting it's often a second-line option for those who haven't responded sufficiently to alternatives.

How long does it take for solriamfetol to work?#

The clinical trials measured outcomes at weeks 2, 5, and 12. Most titration protocols complete within 2 weeks, and meaningful ESS improvements were observed within that timeframe in the SURWEY study ^[6]. However, the full assessment of efficacy and sleep architecture stability should be made at 12 weeks, consistent with the phase 3 trial design.

Why does this study in Chinese patients matter specifically?#

Pharmacogenomic differences across populations can affect drug metabolism, tolerability, and efficacy. Most prior solriamfetol data came from the TONES trials conducted predominantly in Western populations. Wang et al.'s trial is the first large-scale phase 3 specifically in Chinese patients with OSA-EDS, and the fact that both efficacy and sleep architecture preservation held up in this population adds important generalizability to the drug's evidence base ^[1].

VERDICT#

7.5 / 10

The Wang et al. trial answers a question that genuinely needed answering: does solriamfetol wreck your sleep? It appears not to, at least at 150 mg taken in the morning. That's clinically useful information, especially given how many OSA patients and their clinicians have been hesitant about wake-promoting agents precisely because of this concern. The SHARP cognitive data adds a secondary value proposition, though I'm less convinced until the sample sizes grow. The real-world adherence numbers are impressive — a PDC of 0.9 is unusually high for any chronic medication — but the industry funding behind several of these studies keeps me from full-throated enthusiasm. Solriamfetol is a legitimate tool for residual EDS in treated OSA. It's not transformative. It's filling a gap, and the sleep architecture safety data makes it easier to recommend.