URL of this page: https://medlineplus.gov/druginfo/meds/a615004.html

Tasimelteon

pronounced as (tas'' i mel' tee on)

Why is this medication prescribed?

Tasimelteon is used to treat non-24-hour sleep-wake disorder (non-24; a condition that occurs mainly in people who are blind in which the body's natural clock is out of sync with the normal day-night cycle and causes a disrupted sleep schedule.) Tasimelteon is in a class of medications called melatonin receptor agonists. It works similarly to melatonin, a natural substance in the brain that is needed for sleep.

How should this medicine be used?

Tasimelteon comes as a capsule to take by mouth. It is usually taken without food once a day before bedtime. Take tasimelteon at the same time every night. If you are unable to take tasimelteon at your usual time, skip that night's dose. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take tasimelteon exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the capsules whole; do not open or chew them.

You may become sleepy soon after you take tasimelteon. After you take tasimelteon, you should complete any necessary bedtime preparations and go to bed. Do not plan any other activities for this time.

Tasimelteon controls non-24-hour sleep-wake disorder but does not cure it. It may take several weeks or months before you feel the full benefit of tasimelteon. Continue to take tasimelteon even if you feel well. Do not stop taking tasimelteon without talking to your doctor.

Tasimelteon is not available in pharmacies. You can only get tasimelteon through the mail from a specialty pharmacy. Ask your doctor if you have any questions about receiving your medication.

Other uses for this medicine

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What special precautions should I follow?

Before taking tasimelteon,

  • tell your doctor and pharmacist if you are allergic to tasimelteon, any other medications, or any of the ingredients in tasimelteon capsules. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: beta blockers such as atenolol (Tenormin), bisoprolol (Zebeta, in Ziac), carvedilol (Coreg), labetalol (Trandate), metoprolol (Lopressor, Toprol XL), nadolol (Corgard), nebivolol (Bystolic), and propranolol (Inderal); fluvoxamine (Luvox); ketoconazole (Nizoral); and rifampin (Rifadin, Rifamate). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with tasimelteon, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
  • tell your doctor if you have or have ever had liver disease.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking tasimelteon, call your doctor.
  • you should know that tasimelteon may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.
  • ask your doctor about the safe use of alcoholic beverages while you are taking tasimelteon. Alcohol can make the side effects from tasimelteon worse.
  • tell your doctor if you use tobacco products. Cigarette smoking may decrease the effectiveness of this medication.

What special dietary instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget a dose?

Skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can this medication cause?

Tasimelteon may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • headache
  • nightmares or unusual dreams
  • painful, difficult, or frequent urination

Tasimelteon may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

What should I know about storage and disposal of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from light, excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

What other information should I know?

Keep all appointments with your doctor.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

Brand names

  • Hetlioz®
Last Revised - 03/15/2015