How can clinicians reduce crash risk in patients treated for obstructive sleep apnea (OSA) who still have persistent sleepiness? While wake-promoting agents have recently been authorized for this use, sleep hygiene remains the cornerstone of care, said Sébastien Baillieul, MD, Grenoble Alpes University Hospital, at the Congrès du Sommeil 2025, organized jointly by the French Society for Sleep Research and Medicine and the Sleep Group of the French Language Society of Pulmonology.

“In situations of sleep deprivation, prescribing a wake-promoting drug can create a false sense of alertness and confidence,” Baillieul said. That perception is dangerous for patients with OSA who have residual sleepiness despite well-managed continuous positive airway pressure (CPAP) therapy.

OSA is a major public health issue, affecting 4%-10% of French adults. Because of its effectiveness — especially in reducing daytime sleepiness — CPAP remains the reference treatment for moderate-to-severe OSA. Just over 2 million patients with OSA are currently treated with CPAP in France, he noted.

Practical CPAP Threshold

The impact of CPAP on moderate-to-severe daytime sleepiness is strongly tied to adherence. Meta-analysis data show that when average nightly use exceeds 4 hours, residual sleepiness drops sharply and multiple fatigue tests normalize.

Several studies have examined CPAP’s effect on attention deficits that impair driving. One study showed that CPAP normalized drivers’ reaction times to an obstacle, which was simulated by vertical water jets.

More recently, a French observational study, in which Baillieul participated, found a threefold higher risk for road traffic crashes in patients with OSA with poor CPAP adherence — defined as average device use under 4 hours per night (hazard ratio [HR], 3.20). When residual sleepiness at the wheel persisted despite CPAP, crash risk was fivefold higher (HR, 5.4).

CPAP adherence and ongoing sleepiness while driving are two “easy-to-assess” signals of driving-related risk in CPAP-treated patients, he emphasized. “We must stress to patients the importance of adherence, especially when residual sleepiness persists.”

Other Causes of Sleepiness

While more than 4 hours per night remains a good CPAP target, an estimated 6%-13% of adherent patients (6 hours or more per night) still report excessive daytime sleepiness (Epworth score ≥ 11).

French recommendations on residual sleepiness under CPAP advise clinicians to search for other causes. When sleepiness is unexplained, assess for sleep debt using CPAP device data or sleep diaries. “Telemonitoring data from CPAP devices provide an opportunity to identify poor sleep hygiene or maladaptive behaviors,” Baillieul said. “Poor sleep hygiene will undermine daytime alertness even with more than 6 hours of CPAP.”

Screen for psychiatric disorders, particularly using the Hospital Anxiety and Depression Scale to look for depression or anxiety. Inflammatory diseases, cancer, and many neurologic conditions can also cause fatigue and sleepiness.

To gauge crash risk linked to sleepiness at the wheel, use the Bordeaux Sleepiness Scale, a French-developed tool for assessing driver sleepiness risk that incorporates sex and self-perception of sleepiness to flag patients more likely to cause a road crash.

Second-Line Options: Solriamfetol or Pitolisant

Two wake-promoting medications — solriamfetol and pitolisant — have marketing authorization in the EU/European Economic Area for excessive daytime sleepiness. They are indicated for adults with OSA whose sleepiness has not been satisfactorily treated by a primary treatment, such as CPAP.

Solriamfetol is also approved in the US for excessive daytime sleepiness in adults with OSA.

A recent meta-analysis found similar efficacy and benefit-risk profiles for both agents in patients with OSA with residual sleepiness, with clear gains in vigilance on the Epworth Sleepiness Scale and the Oxford Sleep Resistance and Maintenance of Wakefulness Test scores.

Only one small study has tested driving outcomes in OSA-related hypersomnolence (Epworth ≥ 10). In a randomized crossover design, participants received solriamfetol (150 mg/d and 300 mg/d) or placebo. On-road performance improved significantly with solriamfetol, with fewer lane departures. The effect persisted at 2 and 6 hours after dosing.

For professional drivers, a Maintenance of Wakefulness Test, required under French licensing rules for commercial driving, should be performed at least 1 month after starting a wake-promoting drug to renew fitness to drive motor vehicles.

‘Maximize Opportunities for Sleep’

In OSA, “CPAP and pharmacologic treatments can reduce crash risk, but their effectiveness still depends on sleep hygiene and patient education,” Baillieul concluded.

Education is especially critical for professional drivers. “Our role is also to inform them about the risk associated with poor sleep hygiene, especially when job demands are high,” he said. In this group, “we need to maximize opportunities for sleep — particularly during the workweek — and optimize CPAP use during sleep periods.”

This story was translated from Medscape’s French edition.