This medication is used to treat narcolepsy, a condition that causes severe daytime sleepiness. It can decrease daytime sleepiness and also reduce the number of sudden short attacks of weak/paralyzed muscles (known as cataplexy) that can occur in patients with narcolepsy. It may also be used to treat a certain sleep disorder (idiopathic hypersomnia). This medication is a central nervous system depressant. It is a form of a drug known as gamma hydroxybutyrate (GHB).

Read the Medication Guide and Instructions for Use provided by your pharmacist before you start using this medication and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth at least 2 hours after eating as directed by your doctor. This medication is usually taken in 2 separate doses if treating narcolepsy, or in 1 or 2 doses if treating idiopathic hypersomnia. Prepare your doses as directed before bedtime. The doses must each be mixed with 2 ounces (60 milliliters) of water. Take the first dose at bedtime while in bed. If you are directed to take a second dose, set an alarm clock to awaken you for the second dose in 2-and-a-half hours to 4 hours. Take the second dose while sitting in bed, and turn off the alarm. Properly discard prepared doses if not used within 24 hours. If you have children or pets in the house, be sure to use the caps that come with the medication cups in the child-resistant position.

The dosage is based on your medical condition, response to treatment, and other medications you may be taking. Children's dosage is also based on weight. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). Your doctor will gradually increase your dose over 1 to 2 weeks to lessen the risk of side effects. This process will continue until your doctor has found the right dose for you. Follow your doctor's directions carefully. Do not increase your dose, take it more often, or use it for longer than prescribed.

Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each night.

If you suddenly stop using this medication, you may have withdrawal symptoms (such as anxiety, psychosis, fast heartbeat, trouble sleeping). To help prevent withdrawal, your doctor may lower your dose slowly. Withdrawal is more likely if you have used this product for a long time or in high doses. Tell your doctor or pharmacist right away if you have withdrawal.

Tell your doctor if your condition lasts or gets worse.

See also Warning section.

Drowsiness, dizziness, nausea, vomiting, decreased appetite, diarrhea, increased sweating, tiredness, bedwetting, or headache may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• mental/mood changes (such as confusion, hallucinations, agitation, depression, thoughts of suicide)
• numb/tingling skin
• shaking (tremor)
• sleepwalking

Get medical help right away if you have any very serious side effects, including:

• difficult/slow/shallow breathing (especially during sleep)

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking this medication, tell your doctor or pharmacist if you are allergic to sodium oxybate, calcium oxybate, magnesium oxybate, or potassium oxybate; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• a certain rare metabolic condition (succinic semialdehyde dehydrogenase deficiency)
• liver disease
• breathing problems (such as sleep apnea, asthma)
• personal/family history of regular use/abuse of drugs/alcohol
• mental/mood problems (such as depression, family/personal history of suicidal thoughts/attempts)

Sleep disorders may decrease your ability to react quickly. Though this medication helps keep you awake during the day, you still may not be able to safely do tasks that require alertness (such as driving, flying). This drug may also make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. For these reasons, do not drive, use machinery, or do anything that needs alertness until you can do it safely. Always use great care when doing these activities, and avoid them completely during at least the first 6 hours after you take this medication. Avoid alcoholic beverages because they increase the risk of serious side effects. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Older adults may be more sensitive to the side effects of this drug, especially headaches.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This drug passes into breast milk. Consult your doctor before breastfeeding.

See also Warning section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

The risk of serious side effects (such as slow/shallow breathing, severe drowsiness/dizziness) may be increased if this medication is taken with other products that may also cause drowsiness or breathing problems. Tell your doctor or pharmacist if you are using other products such as other opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: lack of response, slow/shallow breathing, seizures.

Do not share this medication with others. Sharing it is against the law.

If you miss your first dose of the night, take it as soon as you remember if it is before bedtime. If it is not at bedtime or if it is your second dose that you missed, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Different brands of this medication have different storage needs. Check the product package for instructions on how to store your brand, or ask your pharmacist. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. For more details, read the Medication Guide, or consult your pharmacist or local waste disposal company.