XYREM^® (sodium oxybate) oral solution, 0.5 g/mL is a prescription medicine used to treat the following symptoms in people who fall asleep frequently during the day, often at unexpected times (narcolepsy):

• suddenly weak or paralyzed muscles when they feel strong emotions (cataplexy)
• excessive daytime sleepiness (EDS) in people who have narcolepsy

XYREM may only be given to patients enrolled in the XYREM REMS Program.

Important Safety Information

WARNING: This medicine can have very serious side effects and has been misused and abused. Do not use with other medicines that slow your breathing or mental activity, or cause sleepiness.

XYREM has caused changes in alertness (or consciousness) and trouble breathing (respiratory depression). Call your doctor right away if you have any of these serious side effects. These effects happened even when XYREM was given in recommended doses. In studies, almost all of the patients with narcolepsy who were given XYREM were also taking medicines to help them stay awake during the day.

XYREM is a form of gamma hydroxybutyrate (GHB). Abuse of GHB alone or with other drugs that cause changes in alertness (or consciousness) has caused serious side effects. These effects include seizures, trouble breathing (respiratory depression), very low levels of alertness (or consciousness), coma, and death.

Do not take XYREM if you take other sleep medicines or sedatives (medicines that cause sleepiness), drink alcohol, or have a rare problem called succinic semialdehyde dehydrogenase deficiency.

XYREM is a controlled substance (CIII) because it contains sodium oxybate that can be a target for people who abuse prescription medicines or street drugs. Never give your XYREM to anyone else because it may cause death or harm them. Selling or giving away this medicine is against the law.

Do not drive a car, use heavy machinery, fly an airplane, or do anything that is dangerous or that requires you to be fully awake for at least 6 hours after you take XYREM. You should not do those activities until you know how XYREM affects you.

XYREM can cause serious side effects, including the following:

• Breathing problems, including slower breathing, trouble breathing, and/or short periods of not breathing while sleeping (sleep apnea). People who already have breathing or lung problems have a higher chance of having breathing problems when they use XYREM.
• Mental health problems, including confusion, seeing or hearing things that are not real (hallucinations), unusual or disturbing thoughts (abnormal thinking), feeling anxious or upset, depression, or thoughts of killing yourself or trying to kill yourself. Tell your doctor if you have or had depression or have tried to harm yourself. Call your doctor right away if you have symptoms of mental health problems.
• Sleepwalking. Sleepwalking can cause injuries. Call your doctor if you start sleepwalking. Your doctor should check you.

Tell your doctor if you are on a salt-restricted diet or if you have high blood pressure, heart failure, or kidney problems. XYREM contains a lot of sodium (salt) and may not be right for you.

The most common side effects of XYREM include nausea, dizziness, vomiting, bedwetting, and diarrhea. Your side effects may increase when you take higher doses of XYREM. XYREM can cause physical dependence and craving for the medicine when it is not taken as directed. These are not all the possible side effects of XYREM.