A new kind of sleeping pill: "Dora-22"
A Sleeping Pill Without The Sleepy Head?
[...] DORA-22 is part of a class of new drugs — one of which the Food and Drug Administration is already considering for approval — known as orexin antagonists.It's an interesting concept. But how many years till we find out the long term side effects?
“It’s high quality research,” says Jerome Siegel, professor of psychiatry at University of California Los Angeles, who was not associated with the study.
The authors compared the sleep-inducing effects of DORA-22 to those of three well-known sleeping pills: diazepam (Valium), zolpidem (Ambien) and eszopiclone (Lunesta), which work by slowing down brain activity. Immediately after giving the animals the drugs, the scientists tested the animals’ memory and reaction time. (While most people take sleeping pills before going to bed, such effects are important to document so researchers, and users, can fully understand how their brains and bodies are affected by the medications in case people don’t take the drugs as prescribed.)
“It’s very enticing because there are some clear results that show [that these drugs] differ from old hypnotic drugs in terms of affecting cognition and memory in two animal species,” says Dr. Emmanuel Mignot, director of the Stanford Center for Sleep Sciences, who wrote a commentary on the research, which was published in Science.
Rats given high enough doses to cause sleep of the three currently available drugs had difficulty recognizing whether they had seen an object previously presented to them, while those dosed with DORA-22 did not show such compromised recall. Similarly, all of the drugs except DORA-22 reduced rhesus monkeys’ ability to react to a touch screen and correctly choose a colored square associated with a reward. In fact, even at doses 30 times higher than the lowest amount needed to affect sleep, the drug did not impair performance on this task.
What makes this new class of drugs different? Orexins, which are also known as hypocretins, are brain chemicals that promote wakefulness. Of the brain’s billions of neurons, only tens of thousands produce orexins. People with narcolepsy who have difficulty staying awake and are prone to suddenly falling asleep without warning are missing almost all of the neurons that produce these chemicals. DORA-22 and similar drugs work by blocking orexins by essentially producing a brief and reversible bout of narcolepsy. [...]