In 2015 Merck started selling the orexin antagonist suvorexant under the brand name Belsomra. The FDA approved the drug in 2014. It is the first insomnia medication intended to act on the orexin neurochemical system.
It is a prescription medicine and under patent, so that it is likely to be expensive for the foreseeable future. It's also the first medicine of this type sold widely. The pharmaceutical industry and the regulators and the medical community will be watching to see how it plays out. In particular, they will watch for incidence and severity of side effects (always a question for a new medicine) and whether doctors and patients choose to stay with this drug after tying it.
Merck lists the potential side effects as
Because this drug suppresses the wake-promoting system in the brain, there is concern about too much sleepiness during the day after you take the drug. When you start this drug, you are advised to avoid driving the next day until you can see how you can handle it and whether you get the side effects.
Tbere were concerns that suvorexant might depress alertness so much it would also suppress breathing and increase the risks of apnea. A dounle-blind study found suvorexan was safe for people with mild to moderate OSA.
This is one reason people with narcolepsy are not supposed to take suvorexant. As a orexin receptor antagonist, it suppresses the arousal system in the brain, and narcoleptics already tend to have low levels of orexin.
The drug has been found effective among elderly patients.
Doctors and patients should welcome the addition of a new hypnotic drug to the list of treatment options, especially one that works though a different mechanism than other insomnia medications.