That means, theoretically, fewer side effects and perhaps less of a tendency to be habit forming, Thorpy explained.
Uslaner and his colleagues investigated a compound called DORA-22, which has the same mechanism of action as suvorexant, to see how it fared alongside not only Ambien and Lunesta but also diazepam (Valium) in rats and rhesus monkeys.
DORA-22 did not lead to the same mental impairments as the other three drugs. Rhesus monkeys and rats performed just as well on memory and attention tasks shortly after being administered DORA-22 as they did on an inactive placebo.
In each case, the minimum dose to achieve sleep was compared with the minimum dose that altered memory and thinking. DORA-22 promoted sleep at lower doses than those that impaired mental skills when compared with the "control" drugs.
This is the first time in years that scientists have targeted a totally different receptor in the quest to combat insomnia, said Dr. Alexandre Abreu, co-director of the UHealth Sleep Center at the University of Miami Miller School of Medicine.
But many questions remain: Do the drugs truly have fewer side effects? Will they be habit forming? And will they change the quality of sleep in any way?
Those questions will only be answered with more testing and use in humans, he said.
Experts note that findings from animal studies do not always hold up in human trials.
The U.S. National Institutes of Health has more on insomnia.
SOURCES: Jason Uslaner, Ph.D., director, In Vivo Pharmacology, Merck & Co.; Michael Thorpy, M.D., director, Sleep-Wake Disorders Center, Mon
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