How Hetlioz Treats Non-24-Hour Sleep-Wake Disorder in Blind People

Hetlioz is a prescription medication, sold under the generic name of tasimelteon, that is used in blind people for treatment of the Non-24-Hour Sleep-Wake Disorder (Non-24). This circadian rhythm disorder may cause cyclical patterns of insomnia and excessive daytime sleepiness.

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Hetlioz is available with a prescription to treat Non-24-Hour Sleep-Wake Disorder. This may also be called free-running or Nonentrained Circadian Rhythm Sleep Disorder. This condition mostly affects totally blind people who have no light perception.

Blindness prevents a light signal from entering the suprachiasmatic nucleus (SCN), part of the brain that regulates the timing of circadian rhythms, including sleep and wakefulness. As a result, the affected person will have circadian patterns that are genetically determined, and not quite 24 hours in length. Often these rhythms are inherently about 24 1/2 hours and this results in a 30-minute shift in sleep onset and waking on a daily basis. This may cause a continual shift in the timing of sleep and other functions. This pattern gradually drifts across the actual 24-hour geological day. As a result, blind people may complain of cycles of insomnia and excessive daytime sleepiness, typically over weeks.

Hetlioz is not approved for use by sighted individuals who do not experience Non-24.

How It Works

Hetlioz works to enhance the effects of the receptors for melatonin. In particular, it binds and augments the MT1 and MT2 receptors within the brain. This induces sleep. Direct comparisons to the effectiveness of melatonin via controlled research trials have not been done.

Who Should Not Use Hetlioz

Caution is recommended with the use of Hetlioz among the elderly, smokers, and in those who use alcohol or other medications that may act to depress the central nervous system (in particular, the brain). It is not recommended in people with severe liver dysfunction.

Animal studies show adverse effects on the fetus in pregnancy, but human studies have not been performed. The safety of use with lactation is unknown. If you are pregnant or nursing, you should discuss the safety and risks versus benefits with your healthcare provider.

Its use has not been studied in children.

Hetlioz has the potential to interact with other medications, so you should review all drugs that you are taking with your healthcare provider if you are using or plan to use Hetlioz.

Side Effects

As with any drug, there is the potential for harmful side effects with the use of Hetlioz. Although you would not be expected to experience most side effects and would likely not experience any of them, some of the more common that can occur with the use of Hetlioz include:

  • Sleepiness
  • Headache
  • Elevation in liver enzymes (Alanine aminotransferase)
  • Abnormal dreams
  • Upper respiratory infection (URI)
  • Urinary tract infection (UTI)

Potential Serious Reactions

Serious reactions may occur with the use of Hetlioz, but none have been reported.

Things to Keep in Mind

There are people who should use Hetlioz with caution or not at all, as noted above. If you are pregnant or nursing, you should discuss the safety and risks versus benefits with your healthcare provider.

No routine testing or safety monitoring is required.

If you have any difficulties with the use of Hetlioz, you should discontinue its use and contact your healthcare provider.

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  • "Hetlioz." Epocrates Rx Pro. Version 14.1, 2014. Epocrates, Inc. San Mateo, California.

By Brandon Peters, MD
Brandon Peters, MD, is a board-certified neurologist and sleep medicine specialist.