It is estimated that up to 100,000 people in the United States have non-24-hour-sleep-wake disorder (N24HSWS). It shares symptoms that are similar to other sleep disorders the criteria for the presence of this disorder is a complain of cyclic insomnia and/or excessive daytime sleepiness.1 This abnormality is suggested to be related to the lack of synchronicity between the 24-hour day-night cycle and the body’s internal clock.1 Individuals who are thought to have this disorder do not have internal clocks that can reset and remain in homeostasis within a 24-hour schedule so in certain situations they can have longer circadian rhythms. 2 Aside from the fact that the condition can cause stress and depression it considered not to be harmful as the quality of deep sleep is equal to those without the disorder.2 Melatonin is considered to be most commonly utilized treatment for the disorder along with light treatment or acupuncture. Hetlioz (tasimelteon) is a melatonin receptor agonist, similar to Rozerem (ramelteon) that was approved by FDA in January 2014 for the treatment of N24HSWS caused by a completely blind person’s inability to regulate their internal clock.3 Hetlioz is available in 20-mg capsules and should be administered as 1 capsule prior to bedtime with food. It works optimally when administered at the same time daily. The drug is produced by Vanda Pharmaceutucals based in Washington, D.C.3,4
Hetlioz is the second drug in the class of melatonin receptor agonist to be released, following Rozerem but unlike Rozerem which has a labeled indication for insomnia characterized by difficulty with sleep onset, Hetlioz is specifically indicated for N24HSWS which is the first approved treatment.3,5 This indication was established in totally blind patients with the disorder.
There are currently no published trials of Hetlioz for the treatment of N24HSWS. However, the results of 2 studies were presented at the 95th Annual Meeting and Expo of The Endocrine Society in 2013. These studies include the SET study (n=84) and the RESET study (n=20).
It is also worthy of note that there have been no clinical research trials that compare the use of Hetlioz and melatonin in a head-to-head fashion. FDA approved Hetlioz based on placebo-controlled trials. Its effectiveness has not to this point been directly compared to taking over-the-counter melatonin, which has previously been the standard of care for this condition. Timed melatonin administration is a “guideline” recommendation by the American Academy of Sleep Medicine and reflects a moderate degree of clinical certainty based on five cohort studies and clinical trials.