Xywav is a prescription drug that’s used to treat excessive sleepiness caused by certain conditions. Xywav comes as a liquid solution that you swallow two times per night.

Xywav is used for managing:

  • symptoms of narcolepsy in adults and certain children ages 7 years and older
  • idiopathic hypersomnia (excessive daytime sleepiness that doesn’t have a clear cause)

To learn more about Xywav’s uses, see the “What is Xywav used for?” section.

Xywav basics

Xywav contains the following active ingredients. An active drug is the ingredient that makes a medication work.

  • calcium oxybate
  • magnesium oxybate
  • potassium oxybate
  • sodium oxybate

Xywav belongs to a group of drugs called central nervous system (CNS) depressants. This drug comes as a liquid solution that you swallow. Xywav is not available as a generic drug. However, sodium oxybate (one of the active ingredients in Xywav) is available as a generic liquid solution. It’s also approved by the Food and Drug Administration (FDA) to treat symptoms of narcolepsy in adults and children ages 7 years and older.

Keep reading to learn more about Xywav, including information about side effects, cost, and more.

Xywav has boxed warnings. A boxed warning is the most serious warning from the FDA. For details, see the “What should be considered before taking Xywav?” section.

Xywav is FDA approved to help manage certain sleep disorders in adults and certain children.

Xywav for narcolepsy

Xywav is used to treat the following symptoms of narcolepsy in adults and children ages 7 years and older:

  • cataplexy, which is an unexpected, temporary loss of muscle control
  • excessive daytime sleepiness, which is an overwhelming, sudden urge to sleep that makes it hard to function during the day

Narcolepsy affects the nervous system, resulting in irregular sleep. Excessive daytime sleepiness and “sleep attacks” (falling asleep suddenly without warning) are the main symptoms of narcolepsy. Some people with narcolepsy also experience cataplexy.

Xywav for idiopathic hypersomnia

Xywav is used to treat idiopathic hypersomnia in adults. For some people with hypersomnia (also known as excessive daytime sleepiness), it’s possible to identify its cause, such as another medication or condition. Idiopathic means there’s no clear cause for the hypersomnia.

People with idiopathic hypersomnia experience excessive sleepiness, even after getting a full night of sleep. With excessive sleepiness, you may frequently feel tired and have trouble concentrating or completing tasks. In turn, this can affect how you function at work or school.

Xywav’s mechanism of action

Xywav’s mechanism of action for treating narcolepsy and idiopathic hypersomnia isn’t known. (A “mechanism of action” is how a drug works.)

It’s thought that the drug improves sleep quality by affecting certain chemicals in the brain.

Like most drugs, Xywav may cause mild or serious side effects. The lists below describe some of the more common side effects of Xywav. These lists don’t include all possible side effects.

Keep in mind that side effects of a drug can depend on:

  • your age
  • other health conditions you have
  • other medications you take

Your doctor or pharmacist can tell you more about the potential side effects of Xywav. They can also suggest ways to help reduce side effects.

Mild side effects

Here’s a short list of some of the mild side effects that Xywav can cause. To learn about other mild side effects, talk with your doctor or pharmacist, or read Xywav’s prescribing information.

Mild side effects of Xywav that have been reported include:

Mild side effects of many drugs may go away within a few days to a couple of weeks. But if they become bothersome, talk with your doctor or pharmacist.

Serious side effects

Serious side effects from Xywav can occur, but they aren’t common. If you have serious side effects from Xywav, call your doctor right away. But if you think you’re having a medical emergency, call 911 or your local emergency number.

Serious side effects of Xywav that have been reported include:

Allergic reaction

For some people, Xywav can cause an allergic reaction.

Allergic reactions weren’t reported in studies of Xywav. However, there have been reports since Xywav became available on the market.

In general, symptoms of allergic reaction can be mild or serious.

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should keep taking Xywav.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Xywav, they may have you switch to a different treatment.

Your doctor will recommend the dosage of Xywav that’s right for you. Below are commonly prescribed dosages, but always take the dosage your doctor prescribes.

Form

Xywav comes as a liquid solution that you swallow.

Recommended dosages

Your doctor will recommend the dosage of Xywav that’s right for you. Below are commonly used dosages, but the dosage you receive will be determined by your doctor.

For a detailed overview of Xywav’s dosages, see this Xywav dosage guide.

Dosage for narcolepsy

The recommended dosage of Xywav for narcolepsy is between 6 and 9 milligrams (mg) per night, taken in two divided doses. Your doctor will likely start you on a lower dose and slowly increase it over time.

Typically, you’ll take your first dose at bedtime and your second dose 2.5 to 4 hours later.

Dosage for idiopathic hypersomnia

When prescribed for idiopathic hypersomnia, Xywav may be taken once or twice every night. Your doctor will likely start you on a low dose and slowly increase it over time.

Your specific dose will depend on multiple factors, including how frequently you take it.

The maximum recommended dosage of Xywav is 6 to 9 mg, depending on whether you take it once or twice per night.

Dosage for children

Xywav is FDA approved to treat symptoms of narcolepsy in children ages 7 years and older. If your child is prescribed Xywav for this use, their specific dosage will depend on their weight. However, they’ll likely take Xywav in two doses every night instead of one.

How to take Xywav

Xywav comes as a liquid solution that you swallow.

It’s important to know that Xywav works very quickly for most people. You’ll likely fall asleep within 5 to 15 minutes after taking a dose. To avoid possible injury, your doctor may suggest that you take Xywav while in bed. Or they may recommend that you get into bed right after taking a dose.

Questions about Xywav’s dosage

Below are some common questions about Xywav’s dosage.

  • Should I take Xywav with food? No, you should not take Xywav with food. You should wait at least 2 hours after eating before taking a dose of Xywav.
  • What if I miss a dose of Xywav? If you miss an Xywav dose, simply skip the missed dose. Never take more than one dose of Xywav to make up for a missed dose.
  • Will I need to take Xywav long term? If you and your doctor agree Xywav is safe and working for you, you’ll likely take it long term.
  • How long does Xywav take to work? Xywav works very quickly. Most people fall asleep within 5 to 15 minutes of taking a dose.

Overdose

Do not take more Xywav than your doctor prescribes. Taking more than this can lead to serious side effects.

What to do in case you take too much Xywav

Call your doctor if you think you’ve taken too much Xywav. You can also call 800-222-1222 to reach America’s Poison Centers, or use its online resource. But if you have severe symptoms, immediately call 911 or your local emergency number. Or go to the nearest emergency room.

Costs of prescription drugs can vary depending on many factors. These factors include what your insurance plan covers and which pharmacy you use.

You may wonder how the cost of Xywav compares with alternatives such as Xyrem. Xywav may be more expensive than Xyrem. To learn more about the price you may pay for either medication, talk with your doctor or insurance company.

If you have questions about how to pay for your prescription, talk with your doctor or pharmacist. You can also visit the Xywav manufacturer’s website to see if it has support options.

To learn more about saving money on prescriptions, check out this article.

Before you begin treatment with Xywav, it’s important to discuss certain aspects of your health with your doctor. These include any medical conditions you have and any medications you take. This information helps them determine whether Xywav is a good treatment option for you.

Interactions

Taking a medication with certain vaccines, foods, and other things can affect how the medication works. These effects are called interactions.

Before taking Xywav, be sure to tell your doctor about all medications you take, including prescription and over-the-counter kinds. Also, describe any vitamins, herbs, or supplements you use. Your doctor or pharmacist can tell you about any interactions these items may cause with Xywav.

Interactions with drugs or supplements

Xywav can interact with several kinds of drugs. These drugs include:

  • sedative hypnotic medications, such as:
  • CNS depressants, such as:

This list does not contain all kinds of drugs that may interact with Xywav. Your doctor or pharmacist can tell you more about these interactions and any others that may occur with Xywav.

Note: Because of possible interactions, your doctor will likely recommend that you do not take Xywav with certain drugs listed above.

Boxed warnings

Xywav has boxed warnings. Boxed warnings are serious warnings from the FDA.

Boxed warnings for Xywav include:

  • Risk of CNS depression: Xywav works by depressing (slowing down) activity in your central nervous system. This is known as CNS depression, and it can happen with Xywav even when it’s taken as directed. CNS depression can impair your judgment, thinking, and motor skills.
  • Risk of misuse: Xywav has a risk of misuse. Misusing Xywav can lead to serious side effects, including trouble breathing or coma. In rare cases, it can even be fatal. To learn more, see the “Can Xywav be misused?” section.

Other warnings

Xywav may not be right for you if you have certain medical conditions or other factors that affect your health. Talk with your doctor about your health history before you take Xywav. Factors to consider include those in the list below.

  • Succinic semialdehyde dehydrogenase deficiency: If you have succinic semialdehyde dehydrogenase deficiency, a rare brain disorder, your doctor will not prescribe Xywav to you. This condition can result in the level of Xywav building up in your body, which may cause serious side effects. Your doctor can suggest safer treatment options for your condition instead of Xywav.
  • Breathing or lung problems: Xywav can lower your breathing rate and cause other breathing issues, including respiratory depression. If you have existing breathing or lung problems, you may have a higher risk of this side effect with Xywav. Let your doctor know if you have such problems. This can help them determine whether Xywav is a safe treatment option for you.
  • Sleep apnea: Xywav can cause sleep apnea. For people who already have this condition, taking Xywav could worsen it. If you have sleep apnea, let your doctor know so they can determine whether Xywav is safe for you to take.
  • Depression: Xywav can cause depression or a depressed mood and can worsen this condition in people who already have it. If you have depression, tell your doctor. This can help them determine whether Xywav is a safe treatment option for you.
  • Suicidal thoughts or actions: In rare cases, Xywav has caused suicidal thoughts or actions. Be sure to talk with your doctor if you have or have had suicidal thoughts or behaviors. Taking Xywav could worsen these feelings. Your doctor will discuss with you whether Xywav is safe for you to take.
  • Liver problems: If you have liver problems, your body may have issues breaking down Xywav after you take a dose. This can result in the level of Xywav building up in your body, which may cause serious side effects. Tell your doctor about any liver problems you have. This can help them determine whether Xywav is a safe treatment option for you.
  • Allergic reaction: If you’ve had an allergic reaction to Xywav or any of its ingredients, your doctor will likely not prescribe Xywav. Ask them what other medications are better options for you.

Help is out there

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

  • Call or text the 988 Suicide and Crisis Lifeline at 988 or chat at 988lifeline.org. Caring counselors are available to listen and provide free and confidential support 24/7.
  • Text HOME to the Crisis Text Line at 741741 to connect with a volunteer crisis counselor for free and confidential support 24/7.
  • Not in the United States? Find a helpline in your country with Befrienders Worldwide.
  • Call 911 or your local emergency services number if you feel safe to do so.

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you’re not in the same household, stay on the phone with them until help arrives.

Xywav and alcohol

You should not drink alcohol during Xywav treatment.

Xywav works by depressing (slowing down) activity in your central nervous system. This is known as CNS depression, and it can impair your judgment, thinking, and motor skills. Like Xywav, alcohol is a CNS depressant. So drinking alcohol while taking Xywav can increase the risk of serious side effects from CNS depression.

For more information about alcohol and Xywav, talk with your doctor.

Pregnancy and breastfeeding

It’s not known if it’s safe to take Xywav during pregnancy or while breastfeeding.

If you’re pregnant or breastfeeding, or planning for either, tell your doctor. They can discuss safe treatment options for your condition with you.

Find answers to some commonly asked questions about Xywav.

Is Xywav an alternative to Xyrem?

Though Xywav and Xyrem are very similar, they’re also different in a few ways.

Both Xywav and Xyrem are used to treat symptoms of narcolepsy in adults and some children. But Xywav may also be used to treat idiopathic hypersomnia in adults.

Xywav and Xyrem both contain sodium oxybate as an active drug. But Xywav also contains the active drugs calcium oxybate, magnesium oxybate, and potassium oxybate. This means Xywav has less sodium (salt) than Xyrem. So it may be a safer option for people who are limiting their salt intake.

If you’d like to learn more about how Xywav compares with Xyrem, talk with your doctor or pharmacist.

Is Xywav a controlled substance?

Yes, Xywav is a controlled substance. This means that certain laws in the United States control how Xywav is prescribed to help prevent possible misuse (sometimes called abuse). Misuse occurs when a person uses a drug in a way other than how it’s prescribed. Misusing Xywav can lead to serious side effects, including trouble breathing or coma.

Xywav is considered a Schedule III controlled substance. A Schedule III substance has an approved medical use, but it also has risks of misuse, dependence, and tolerance. With dependence, the body needs a drug to function as it usually would. Tolerance means the body gets used to a drug and needs a higher dose for the same effect.

In addition, distribution of Xywav is restricted through a program called a risk evaluation and mitigation strategy (REMS). As a result, the drug is available only from certain prescribers and a specially certified pharmacy. The Food and Drug Administration (FDA) requires certain medications to have a REMS to help manage serious risks associated with those medications.

To learn more, see the “Can Xywav be misused?” section.

Xywav has a boxed warning about the risk of misuse.

Misuse (sometimes called abuse) occurs when a person uses a drug in a way other than how it’s prescribed. Misusing Xywav can lead to serious side effects, including trouble breathing or coma. It can even be fatal in rare cases.

Before you begin taking Xywav, it’s important to tell your doctor if you have a history of substance use disorder. This can help them determine whether Xywav is a good treatment option for your condition.

About the Xywav REMS program

Due to the risk of misuse and CNS depression, distribution of Xywav is restricted through a program called a risk evaluation and mitigation strategy (REMS).

The FDA requires certain medications to have a REMS to help manage serious risks associated with those medications. The REMS program ensures that Xywav is prescribed only when its benefits outweigh its risks.

Because of the REMS program, only specially certified healthcare professionals can prescribe Xywav. And only a specially certified pharmacy may dispense the drug. This means you will not be able to pick it up from your local pharmacy.

To be prescribed Xywav, you must enroll in the Xywav REMS program. You also need to complete documentation that indicates you’re taking the drug safely as your doctor prescribes.

To learn more about the Xywav REMS program, talk with your doctor or pharmacist. You can also check out the Xywav REMS website, or call 866-997-3688.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.