Kimm Saatvedt via Sundance InstituteThe FDA just approved the first drug designed to treat a sleep disorder called non-24-hour sleep-wake cycle.
The disorder, also called non-24, is a circadian rhythm disorder experienced by completely blind individuals.
Because they don't perceive light at all completely blind people have no way of knowing if its day or night. This completely messes up their sleep schedules.
The circadian rhythm is an internal clock that tells our body when to sleep. It relies on cues from sunlight to stay on track. Most people who are completely blind can still perceive enough light to keep them on a normal schedule. But some cannot perceive light well enough, and so their circadian rhythm doesn't synchronize with the natural light-dark cycle. According to the FDA there could be as many as 100,000 individuals in the U.S. that have the disorder.
Those with the disorder have trouble falling asleep and staying asleep, and often wake up feeling like they need more rest. People who have non-24 can even end up with a reversed sleep pattern: sleeping during the day and staying up during the night.
Even though non-24 was identified as a disorder more than 60 years ago, this drug, called Hetlioz, is the first that effectively treats the condition.
"Non-24-hour sleep-wake disorder can prevent blind individuals from following the normal daily schedule that we all take for granted," Eric Bastings, from the FDA's Center for Drug Evaluation and Research, said in a press release. "Hetlioz can improve the ability to sleep at night and to be active during the day."
The active ingredient in Hetlioz helps activate melatonin — one of our body's hormones that governs sleep. It's taken at night, every night, at the same time.
The FDA approval was based on two trials with 104 people total. Those who took Hetlioz reported both significant increases in nighttime sleep, and significant decreases in daytime sleep. The most common side effects experienced were headache, elevated liver enzymes, nightmares or unusual dreams, and upper respiratory or urinary tract infections.