People taking common sleep drug may not realize they're too impaired to drive, study finds
A popular antipsychotic medication was found to reduce obstructive sleep apnea (OSA) – but it also led to impaired driving the next morning.
That’s according to a small randomized controlled trial published in the Annals of the American Thoracic Society.
Researchers from Flinders University in Adelaide, Australia, conducted the study in 15 adults with OSA who also had difficulty maintaining sleep. Each participant underwent two overnight sleep studies approximately one week apart, according to a press release.
The participants took 50mg of quetiapine (Seroquel) before bed one night, and took a placebo the following night.
Quetiapine is a widely prescribed antipsychotic that is prescribed for schizophrenia, bipolar disorder and depression. It is also often used off-label at lower doses to treat insomnia, anxiety and other sleep issues.
The researchers monitored the participants throughout the night, looking at their breathing, brain activity, oxygen levels and leg movements.
The participants who took the quetiapine had more than 40 minutes more total sleep time and 45% less wakefulness during the night, the study found. Their apnea-related events also reduced from 27 to 20 events per hour.
Despite these improvements, the drug appeared to slow reaction time behind the wheel compared to those taking a placebo. This was based on a driving simulator test and a 10-minute reaction time test, administered within 30 minutes of waking up.
Those taking quetiapine experienced more than triple the number of attention lapses and swerved out of their lane more often in the driving simulator.
Eleven out of 15 of the participants reported feeling sleepier the morning after taking the medication, but roughly one in four people did not recognize their level of impairment. This was concerning because they may be more likely to operate a vehicle or machinery without realizing their reaction time had slowed.
Other mild to moderate side effects included nausea, restless legs and a sudden blood pressure drop upon standing, which affected one in three people taking quetiapine.
The study did have some limitations, including the small sample size, the authors noted. The participants were only evaluated for one night, and the study’s laboratory setting may not reflect the participants’ real-world use.
Larger, longer-term studies are needed to confirm the findings before making decisions about prescribing quetiapine for sleep apnea and insomnia, the researchers said.
Pending follow-up studies, the researchers recommend that people avoid driving or other safety-critical tasks for at least 9.5 hours after taking quetiapine.
Ashley Curtis, PhD, director of the Cognition, Aging, Sleep and Health (CASH) Lab at the University of South Florida, noted that certain hypnotic medications exhibit sex differences in metabolism.
Women generally metabolize these drugs more slowly than men, which can influence both efficacy and the risk of next-day side effects, warned the expert, who was not involved in the study.
"Future studies should carefully examine whether these newer agents demonstrate similar sex-specific patterns to ensure optimal dosing and safety recommendations," she told Fox News Digital.
The impact of quetiapine on next-day cognitive function warrants further investigation, particularly among older adults, according to Curtis.
"This population is already vulnerable to cognitive and related side effects related to polypharmacy, making it essential to understand the potential trade-offs between sleep benefits and daytime functioning," she added.
Insomnia is often the result of "learned behavioral and cognitive factors" that persist over time, according to Curtis.
"Even when medications are effective in the short term, behavioral interventions such as cognitive behavioral therapy for insomnia remain an important component of long-term management," she said.
Chelsie Rohrscheib, head sleep expert at Wesper, a sleep analysis company in New York, agreed that patients shouldn't be alarmed by these findings.
"But if they're taking quetiapine for sleep, especially if they have sleep apnea or wake up feeling groggy, they should talk with their doctor about whether the benefits outweigh the risks and whether other treatment options might be appropriate," noted Rohrscheib, who was not affiliated with the research.