New directions in the pharmacologic treatment of insomnia

This article reviews the recently Food and Drug Administration-approved sleep-promoting medications as well as new compounds being investigated as possible future insomnia treatments. The new medications indicated for the treatment of insomnia include significant advances in pharmacokinetic and pharmacodynamic approaches. All approved sleep-promoting medications are indicated for difficulties with sleep onset and some have an additional indication for sleep maintenance. The recently approved insomnia medications no longer have an implied restriction on their duration of use. There is now a controlled-release formulation of a benzodiazepine receptor agonist, as well as a selective melatonin receptor agonist. New potential pharmacologic targets for treating insomnia have become evident, with advances in the understanding of the neural mechanisms regulating the sleep-wake cycle. Currently being evaluated are a wide range of compounds that modulate γ-aminobutyric acid, histamine, serotonin, melatonin, adenosine, corticotrophin-releasing factor, and hypocretin/orexin systems.