Hetlioz LQ is a sedative that is used to treat non-24-hour sleep-wake disorder in adults.

Hetlioz LQ is also used to treat nighttime sleep problems in people with a genetic disorder called Smith-Magenis Syndrome (SMS). The capsule form of tasimelteon is for people with SMS who are at least 16 years old. The oral suspension (liquid) form is for children with SMS who are from 3 to 15 years old.

Hetlioz LQ may also be used for purposes not listed in this medication guide.

Use only as directed. Tell your doctor if you use other medicines or have other medical conditions or allergies.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Take the medicine without food, 1 hour before your normal bedtime at the same time each night.

Read and follow all Instructions for Use. Ask your doctor or pharmacist if you need help. Do not allow a young child to use Hetlioz LQ without help from an adult.

Swallow the capsule whole and do not crush, chew, break, or open it.

Hetlioz LQ capsules are for use in people 16 years and older. This medicine oral suspension is for use only in children 3 to 15 years old.

Shake the oral suspension for at least 30 seconds before you measure a dose. Use the supplied syringe or a dose-measuring device (not a kitchen spoon). Do not remove the syringe adapter from the bottle neck. Recap the bottle and refrigerate after each use.

The capsules and liquid are not equivalent. Avoid medication errors by using only the form your doctor prescribes.

Doses are based on weight in children. Your child's dose may change if the child gains or loses weight.

You may not fully benefit from this medicine for several weeks or months.

Store capsules at room temperature away from moisture, heat, and light.

Store the liquid medicine in the refrigerator. Throw away any leftover liquid 5 weeks after opening the 48 mL bottle, or 8 weeks after opening the 158 mL bottle.

Tell your doctor if you have ever had:

• liver disease; or

• if you smoke.

Tell your doctor if you are pregnant or breastfeeding.

Do not give Hetlioz LQ to a child without medical advice. Hetlioz LQ is approved to treat nighttime sleep problems only in children who have SMS and are at least 3 years old. This medicine is not approved to treat non-24-hour sleep-wake disorder in anyone younger than 18 years old.

Skip the dose if you cannot take it at the regular time on a given night.

Do not use two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

After taking Hetlioz LQ, avoid doing anything other than getting ready for bed.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have pain or burning when you urinate.

Side effects may be more likely in older adults.

Common side effects of Hetlioz LQ may include:

• headache;

• abnormal liver function tests;

• strange dreams, nightmares; or

• cold symptoms such as stuffy nose, sneezing, sore throat.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Using Hetlioz LQ with other drugs that make you drowsy can worsen this effect. Ask your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures.

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Other drugs may affect Hetlioz LQ, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.