Tasimelteon for insomnia.

INTRODUCTION: Insomnia is a prevalent disorder with nearly 50% of the US adult population reporting insomnia symptoms during the past year and 10 - 15% reporting chronic insomnia. In addition, insomnia is a frequent comorbidity with depression, anxiety and pain, as well as other medical and psychiatric disorders. Tasimelteon is a melatonin receptor agonist developed by Bristol-Myers Squibb Co. and later licensed to Vanda Pharmaceuticals in 2004. It is being developed for the treatment of sleep disorders, including insomnia and mood disorders. AREAS COVERED: The nature and prevalence of insomnia are described in this review, along with the current pharmacological treatments for the disorder. Summaries of the available pharmacological and clinical data for tasimelteon are also provided. A Medline search using the terms tasimelteon, melatonin and insomnia was undertaken to assess the current literature on these topics. EXPERT OPINION: While the few clinical trials of the medication have been promising, much more extensive testing, along with more detailed reporting of the drug's pharmacokinetics and pharmacodynamics, is needed before tasimelteon can be considered a worthwhile addition to the available treatments for insomnia. In particular, testing of the drug's effectiveness in treating maintenance insomnia, as well as tests of its long-term effectiveness and safety, is much needed.