A novel agent, Gaboxadol is being developed for insomnia:
Gaboxadol significantly improved sleep initiation and maintenance while also increasing time spent in restorative slow-wave sleep in an acute phase II placebo-controlled trial, Stephen Deacon, Ph.D., reported at the annual meeting of the Associated Professional Sleep Societies.
Based upon these and other encouraging findings, gaboxadol—first in a novel class of sleep medications known as selective extrasynaptic γ-aminobutyric acid-A agonists, or SEGAs—is now in larger definitive phase III clinical trials, added Dr. Deacon, head of clinical development for sleep disorders at H. Lundbeck, Ltd., Milton Keynes, England.
The benzodiazepine receptor agonists, a class of drugs widely prescribed for insomnia, also target γ-aminobutyric acid (GABA) receptors; however, their action is confined to synaptic GABA receptors. The extrasynaptic GABA-A receptors modulated by gaboxadol are richly present in parts of the brain thought to be important in sleep regulation, he explained.
We are learning more about the GABA-A receptor every day. It will be interesting to see how Gaboxadol compares with the synaptic GABA-A agonists in efficacy and tolerability.