Xywav is a brand-name prescription medication. It’s approved to treat the following narcolepsy symptoms in adults and children ages 7 years and older:

  • cataplexy, which refers to sudden, brief episodes of muscle weakness or paralysis that occur while you’re awake
  • excessive daytime sleepiness (EDS), which is a strong feeling of sleepiness that may occur suddenly while you’re awake

Narcolepsy is a condition that causes interrupted sleep, cataplexy, and EDS. For more information about Xywav’s approved uses, see the “Xywav uses” section below.

Drug details

Xywav contains the active drug ingredients calcium oxybate, magnesium oxybate, potassium oxybate, and sodium oxybate. It belongs to a group of drugs called central nervous system (CNS) depressants. Xywav works to treat narcolepsy symptoms by increasing the amount of deep sleep you get when you’re resting. This can help you feel less sleepy when you’re awake.

Xywav comes as a solution that’s taken by mouth, twice per night. Before taking the solution, you’ll dilute it (add a certain amount of water to it). Xywav is available in one strength: 0.5 g/mL.

FDA approval

In July 2020, Xywav was approved by the Food and Drug Administration (FDA). The drug received orphan drug status*. This means that it’s approved to treat a rare condition that affects less than 200,000 people in the United States. Narcolepsy, which Xywav is approved to treat, is a rare condition that affects between 135,000 and 200,000 people in the United States.

Xywav is also the first low-sodium (low-salt) formulation of sodium oxybate. The type of sodium oxybate in Xywav contains 92% less sodium compared with the type of sodium oxybate in other narcolepsy drugs.

Since Xywav is low-sodium, it’s generally a safer option for people who are limiting their salt intake. When a drug is high-sodium, people who need to limit their salt intake might not be able to take the drug. This may include people with certain conditions, such as hypertension (high blood pressure), heart conditions, or kidney disease.

* Orphan drug status may also be called orphan designation or orphan status. Drugs that are approved under orphan drug status go through clinical trials to prove that the medication is safe and effective, like other FDA-approved drugs.

Is Xywav a controlled substance?

Yes, Xywav is a controlled substance. This means that the drug’s use is controlled by the government to prevent possible misuse. Misusing medications such as Xywav, especially if used with other CNS depressants, can cause CNS depression. This can cause serious side effects such as seizures, trouble breathing, or coma. It can also be fatal. (For more information on CNS depression as a side effect of Xywav, see the “Xywav side effects” section below).

Drugs such as Xywav can sometimes cause dependence. (With dependence, your body needs the drug in order for you to feel normal.) It’s also possible to build up a tolerance to the drug. (With tolerance, you feel like you need to take more and more drug to have the same effect over time.) Either of these conditions may lead to misuse of Xywav.*

One of Xywav’s active drug ingredients, sodium oxybate, is a form of gamma-hydroxybutyrate (GHB). GHB is a Schedule One (I) controlled substance that’s illegal and has a high potential for misuse. In fact, Schedule I controlled substances have no currently accepted medical uses.

Xywav itself is a Schedule Three (III) controlled substance. This means that although there are risks of misuse, tolerance, and dependence, the drug does have an approved medical use.

The FDA requires that Xywav be prescribed only through a Risk Evaluation Mitigation Strategy (REMS) program. This program helps make sure that you and your doctor are aware of your risks for misusing the drug, and your other risks such as CNS depression.

If you have questions or concerns about your risk for misusing Xywav, talk with your doctor. They can help determine a treatment plan that’s best for you.

* To learn more, see the “Xywav withdrawal and dependence” section below.

Effectiveness

For information about the effectiveness of Xywav, see the “Xywav uses” section below.

Xywav is available only as a brand-name medication. It’s not currently available in generic form.

A generic drug is an exact copy of the active drug in a brand-name medication. Generics usually cost less than brand-name drugs.

The Xywav dosage your doctor prescribes will depend on several factors. These include:

  • the severity of the condition you’re using Xywav to treat
  • your age (and, in children only, body weight)
  • your body’s response to Xywav, such as how the drug affects your symptoms and whether you have side effects
  • other medical conditions you may have
  • other medications you’re taking

Typically, your doctor will start you on a low dosage. Then they’ll adjust it over time to reach the amount that’s right for you. Your doctor will ultimately prescribe the smallest dosage that provides the desired effect.

The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Drug forms and strengths

Xywav comes as a solution that’s taken by mouth. It’s available in one strength: 0.5 grams (g) of Xywav per milliliter (mL) of solution. Xywav solution comes in 180-mL bottles.

Before taking Xywav, you’ll dilute (add a certain amount of water to) the solution. Xywav bottles come with a syringe to measure your dose of solution. The drug also comes with containers in which you can dilute the solution. For more information, see the “How to take Xywav” section below.

Dosage for cataplexy or excessive daytime sleepiness in people with narcolepsy

The typical starting dosage of Xywav is 4.5 g per night. It’s taken in two separate doses:

  • the first dose is taken right before you go to sleep, and
  • the second dose is 2.5 to 4 hours after the first dose

Note: If you currently take Xyrem (another drug used to treat narcolepsy symptoms), your starting dosage of Xywav will likely match your current dosage of Xyrem. See “Dosage when switching from Xyrem to Xywav” below for more information.)

Your doctor may increase your Xywav dosage by up to 1.5 g per night each week, until the drug is working to treat your symptoms. The following dosing table an example of how your doctor may recommend increasing your doses:

If your total nightly Xywav dose is:Your first dose of Xywav may be:Your Xywav dose 2.5 to 4 hours later may be:
4.5 g2.25 g2.25 g
6 g3 g3 g
7.5 g3.75 g3.75 g
9 g4.5 g4.5 g

The recommended maintenance dosage of Xywav for treating cataplexy or excessive daytime sleepiness (EDS) is 6 g to 9 g per night.

You shouldn’t take more than 9 g of Xywav per night. Dosages higher than 9 grams haven’t been studied. So it isn’t known whether they may be safe to take.

In some cases, Xywav may be more effective when taken in unequal doses, instead of taking the same amount in each of your two doses. So talk with your doctor about how sleepy you feel during the day and what symptoms you’re still having with Xywav. This can help your doctor determine the best dosage for you.

Also, if you have certain conditions, such as liver problems, your doctor may recommend a different dosage of Xywav that’s not listed above. Make sure to talk with your doctor about the best dosage for you, as well as other medical conditions you have.

Note: Both of your Xywav doses must be prepared before you go to sleep. And you should lie down right after each dose because the drug can cause you to fall asleep quickly. For more information, see the “How to take Xywav” section below.

Dosage when switching from Xyrem to Xywav

If you currently take Xyrem and you’re switching to Xywav, your dosage will typically stay the same. In some cases, your doctor may adjust your dosage, depending on your medical needs.

Make sure to follow your doctor’s instructions when switching your medications. You’ll likely start taking Xywav the night after you take your last Xyrem dose. Your doctor will monitor you to make sure that your Xywav dosage is working to treat your symptoms.

Like Xywav, Xyrem is used to treat cataplexy and EDS caused by narcolepsy. However, Xywav contains less sodium (salt) than Xyrem does. And low-sodium drugs may be safer for people with certain conditions. For more information, see “What is the difference between Xywav and Xyrem?” in the “Common questions about Xywav” section below.

Children’s dosage

Xywav is approved for use in children ages 7 years and older, as well as adults. Unlike adult dosages, children’s dosages of Xywav are based on the child’s body weight.

Similar to dosages in adults, children’s dosages will start low. The child’s doctor may then increase or adjust the dosage each week, based on how well the drug is working.

In children weighing 44 pounds (20 kilograms) or more, dosing is based on the table below:

If the child’s weight in pounds (lb) and kilograms (kg) is:Their starting first dose may be:Their starting dose 2.5 to 4 hours later may be:Their maximum total weekly dose increase may be:Their maximum total nightly dose may be:
44 lb to less than 66 lb (20 kg to less than 30 kg)up to 1 gup to 1 g1 g6 g
66 lb to less than 99 lb (30 kg to less than 45 kg)up to 1.5 gup to 1.5 g1 g7.5 g
99 lb (45 kg or more)up to 2.25 gup to 2.25 g1.5 g9 g

Similar to adults, unequal doses may work better for some children. Xywav is not recommended for use in children who weigh less than 44 lb (20 kg).

Instructions for taking Xywav are the same for children as they are for adults. See the “How to take Xywav” section below for details.

What if I miss a dose?

If you miss taking your first dose of Xywav, you may take it if you remember before it’s time for your later dose. For information about what to do if you miss your first dose of Xywav, talk with your doctor.

If you miss your second dose of Xywav (which is typically taken 2.5 to 4 hours after the first dose), skip the missed dose. And don’t take any more Xywav until the following night.

Never take two doses of Xywav at once to make up for a missed dose. Doing this can increase your risk for side effects, including confusion or problems breathing.

To help make sure that you don’t miss a dose, try using a medication reminder. This can include setting an alarm on your phone or downloading a reminder app. A kitchen timer can work, too.

Will I need to use this drug long term?

Xywav is meant to be used as a long-term treatment. If you and your doctor determine that Xywav is safe and effective for you, you’ll likely take it long term.

Xywav can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Xywav. These lists do not include all possible side effects.

For more information about the possible side effects of Xywav, talk with your doctor or pharmacist. They can give you tips on how to deal with any side effects that may be bothersome.

Note: The Food and Drug Administration (FDA) tracks side effects of drugs it has approved. If you would like to notify the FDA about a side effect you’ve had with Xywav, you can do so through MedWatch.

Mild side effects

Mild side effects* of Xywav can include:

Most of these side effects may go away within a few days or a couple of weeks. But if they become more severe or don’t go away, talk with your doctor or pharmacist.

* This is a partial list of mild side effects from Xywav. To learn about other mild side effects, talk with your doctor or pharmacist, or view Xywav’s medication guide.

Serious side effects

Call your doctor right away if you have serious side effects. Call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.

Serious side effects and their symptoms can include:

* For more information about this side effect, see “Side effect details” below.
Xywav has a boxed warning for this side effect. A boxed warning is the most serious warnings from the FDA. It alerts doctors and patients about drug effects that may be dangerous.

Side effects in children

Xywav is approved for use in adults and children* ages 7 years and older who have narcolepsy.

Xywav has not been studied in children. However, one of Xywav’s active drug ingredients, sodium oxybate, has been studied in children ages 7 to 17 years old. In these studies, the most common side effects of sodium oxybate included:

A more serious side effect of Xywav called parasomnia occurred in 6% of children taking sodium oxybate clinical trials. And in rare cases, other serious side effects occurred, including:

If you have questions about side effects that your child may experience, talk with your doctor or pharmacist.

* Xywav is only recommended for use in children who weigh 44 pounds (20 kilograms) or more and are 7 years or older. For more information, see the “Xywav uses” section above.

Side effect details

You may wonder how often certain side effects occur with this drug. Here’s some detail on certain side effects this drug may cause.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Xywav. It isn’t known how many people taking Xywav in clinical studies may have had an allergic reaction to the drug.

Symptoms of a mild allergic reaction can include:

  • skin rash
  • itchiness
  • flushing (warmth, swelling, and redness in your skin)

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include:

  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your tongue, mouth, or throat
  • trouble breathing

Call your doctor right away if you have an allergic reaction to Xywav, as the reaction could become severe. Call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.

Central nervous system depression

Central nervous system (CNS) depression is a rare but very serious side effect of Xywav. In fact, Xywav has a boxed warning for CNS depression. A boxed warning is the most serious warning from the FDA. It alerts doctors and patients about drug effects that may be dangerous.

Xywav belongs to a group of drugs called CNS depressants. These types of drugs work to depress (slow down) the activity of the central nervous system. They may cause side effects such as a slowed breathing rate, decreased blood pressure, or sleepiness.

CNS depression is when the body’s nervous system functions slow down. This can cause serious side effects such as seizures, trouble breathing, or coma. CNS depression can even be fatal. It’s more likely to occur if you misuse Xywav or take Xywav with other CNS depressants.

It’s not known how many people taking Xywav in clinical studies may have had CNS depression. But trouble breathing and slowed breathing rates have occurred in people taking sodium oxybate, which is one of Xywav’s active drug ingredients.

To lower your risk for CNS depression:

  • Avoid drinking alcohol or taking other CNS depressants while you’re taking Xywav. Alcohol is a CNS depressant, as are some pain medications and some antidepressants. For examples of CNS depressant drugs and more information about potential interactions, see the “Xywav Interactions” section below.
  • Talk with your doctor about any other medications you’re taking before you start taking Xywav. Your doctor can determine if any of your current medications are CNS depressants. They can also discuss your risk for CNS depression.
  • For at least 6 hours after taking a dose of Xywav, avoid activities that could be dangerous to do while you’re sleepy. This includes driving. Waiting this long helps make sure you don’t develop symptoms of CNS depression. It’s important to talk with your doctor about your safety when driving a car or doing activities that require your attention.

If you have questions about your risk for CNS depression while taking Xywav, talk with your doctor. They can help determine your risk for this side effect and ways to help avoid it.

Note: Xywav is a controlled substance that can only be prescribed through a Risk Evaluation Mitigation Strategy (REMS) program. This means only certain doctors and pharmacies are able to prescribe and dispense this medication. For more information, see “Is Xywav a controlled substance?” in the “What is Xywav” section above.

Misuse

It’s possible to misuse Xywav. For this reason, Xywav has a boxed warning for misuse. A boxed warning is the most serious warning from the FDA. It alerts doctors and patients about drug effects that may be dangerous.

Drugs such as Xywav can sometimes cause one or both of the following conditions:

  • dependence, which is when your body needs the drug in order for you to feel normal
  • tolerance, which is when you feel like you need to take more and more drug to have the same effect over time

Either of these conditions can lead to misuse of Xywav. Misusing medications like Xywav, especially if used with other CNS depressant drugs,* may lead to CNS depression. This is when the body’s nervous system functions slow down. CNS depression can cause serious side effects such as seizures, trouble breathing, or coma. CNS depression can even be fatal.

It’s not known how many people taking Xywav in clinical studies experienced misuse, dependence, or tolerance. However, one of Xywav’s active drug ingredients, sodium oxybate, is a form of gamma-hydroxybutyrate (GHB). And GHB is a substance that’s illegal and has a high potential for misuse.

Note: Xywav is a controlled substance that can only be prescribed through a Risk Evaluation Mitigation Strategy (REMS) program. This means only certain doctors and pharmacies are able to prescribe and dispense this medication. For more information, see “Is Xywav a controlled substance?” in the “What is Xywav” section above.

* Xywav is a central nervous system (CNS) depressant. These types of drugs work to depress (slow down) the activity of the central nervous system.

Sleepwalking

Xywav may cause sleepwalking in some cases.

In a clinical study,* 6% of people taking Xywav had parasomnia. Parasomnia refers to unusual behaviors that occur while you’re sleeping, such as:

  • abnormal dreams
  • sleepwalking
  • talking in your sleep

However, it isn’t known exactly how many people in this trial experienced sleepwalking while taking Xywav.

Sleepwalking was also reported in adults and children who took sodium oxybate, one of Xywav’s active drug ingredients. Sleepwalking can become dangerous or cause injury. If you’re sleepwalking or experiencing other types of parasomnia while taking Xywav, talk with your doctor. They can recommend ways to make these side effects less likely or less bothersome

* In this clinical study, it also isn’t known how many people may have experienced parasomnia while taking a placebo. (A placebo is a treatment with no active drug.)

Breathing problems

It’s possible to have breathing problems while you’re taking Xywav. Specifically, Xywav may decrease your ability to breathe properly or even cause sleep disorders, such as sleep apnea. (With sleep apnea, you stop and then restart breathing while you sleep. This condition can cause you to get less oxygen than usual.)

It’s not known how many people taking Xywav in clinical trials had breathing problems. However, in three studies* of adults who took Xyrem, breathing problems did occur. Xyrem is a narcolepsy drug that contains sodium oxybate, which is one of Xywav’s active drug ingredients. The results of these studies are summarized below:

  • In one study, no one who took Xyrem had a decreased oxygen level. However, one person with a history of sleep apnea before taking the drug had their sleep apnea get worse.
  • In another study, however, a small number of people taking Xyrem had breathing problems. Specifically:
    • About 1.6% of people taking Xyrem had significant central nervous system (CNS) depression†. This group of people needed help breathing in order to get their low oxygen levels back to normal. CNS depression is a rare but very serious side effect that can cause seizures, trouble breathing, or coma. It can even be fatal.
    • About 1.6% of people stopped taking Xyrem due to trouble breathing and an increase in their existing sleep apnea.
  • Another study looked at people with obstructive sleep apnea‡ taking Xyrem. In this study:
    • Xyrem didn’t increase the severity of obstructive sleep apnea. The drug also didn’t worsen low oxygen levels caused by obstructive sleep apnea.
    • However, about 6% of people had large decreases in their oxygen levels while taking Xyrem. Large decreases in oxygen can be dangerous. Due to these results, people with pre-existing sleep apnea may have an increased risk for severely decreased oxygen levels while taking Xywav.

If you have a history of breathing problems or sleep apnea, be sure to tell your doctor before you start taking Xywav. These conditions may increase your risk for breathing problems while you’re taking Xywav. Your doctor may monitor you more often than usual for symptoms of decreased oxygen. Or your doctor may recommend a different medication to treat your narcolepsy.

* In these clinical studies, it isn’t known how many people may have experienced breathing problems while taking a placebo. (A placebo is a treatment with no active drug.)
Xywav has a boxed warning for this side effect. A boxed warning is the most serious warnings from the FDA. It alerts doctors and patients about drug effects that may be dangerous.
‡ With obstructive sleep apnea, tissue in the back of your mouth or throat blocks air from getting through to your lungs while you’re sleeping.

Mental health conditions

Certain mental health conditions may occur while taking Xywav. These conditions may include depression or suicidal thoughts or behaviors.

In a clinical study,* 3% to 4% of adults taking Xywav experienced depression or a depressed mood. Of this group of people, about 1% of adults stopped taking Xywav due to depression.

Other clinical studies* looked at adults taking Xyrem. Xyrem is a narcolepsy drug that contains sodium oxybate, which is one of Xywav’s active drug ingredients. In these studies:

  • 7% of adults who took Xyrem reported depression
  • less than 1% of adults stopped using Xyrem due to symptoms of depression
  • 0.25% of adults who took Xyrem died due to suicide

In clinical studies* of children taking Xyrem:

  • about 1% of children reported suicidal thoughts or behaviors as a side effect
  • about 2% of children reported depression as a side effect

Symptoms of depression can include:

  • losing interest in activities that used to excite you
  • feeling irritable
  • changes in appetite or weight
  • trouble sleeping or sleeping too much
  • trouble concentrating

If you have any symptoms of depression or suicidal thoughts or behaviors while taking Xywav, it’s important to talk with your doctor right away. They may be able to recommend ways to help prevent these side effects. They may also recommend a medication other than Xywav to treat your narcolepsy symptoms.

Also, be sure to tell your doctor if you have a history of depression or suicidal thoughts or behaviors. Having these things in your history may increase your risk for developing them as side effects. Your doctor may monitor you more closely than usual for symptoms of depression or suicidal thoughts or behaviors during your Xywav treatment.

* In these clinical studies, it isn’t known how many people may have experienced depression or suicidal thoughts or behaviors while taking a placebo. (A placebo is a treatment with no active drug.)

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

  • Ask the tough question: “Are you considering suicide?”
  • Listen to the person without judgment.
  • Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
  • Stay with the person until professional help arrives.
  • Try to remove any weapons, medications, or other potentially harmful objects.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The National Suicide Prevention Lifeline is available 24 hours per day at 800-273-8255. During a crisis, people who are hard of hearing can call 800-799-4889.

Click here for more links and local resources.

The Food and Drug Administration (FDA) approves prescription drugs such as Xywav to treat certain conditions.

Xywav is FDA-approved for use in adults and children ages 7 years and older who have narcolepsy. Narcolepsy is a condition that affects your sleep cycle. It causes you to have interrupted sleep, which may lead to feeling sleepy or falling asleep during the day. People with narcolepsy may even fall asleep during regular activities, such as driving or eating.

Xywav is approved to treat two possible symptoms of narcolepsy: cataplexy and excessive daytime sleepiness (EDS). These uses are discussed in the sections below.

Xywav for cataplexy in people with narcolepsy

Xywav is approved to treat cataplexy in adults and children ages 7 years and older with narcolepsy. With cataplexy, sudden, brief episodes of muscle weakness or paralysis occur while you’re awake.

Symptoms of cataplexy can range in severity. You may have weakness in small muscles (for example, drooping eyelids). Or you may have more severe muscle weakness, which may cause you to collapse.

Effectiveness for cataplexy in people with narcolepsy

Xywav has been effective in treating cataplexy in people with narcolepsy.

In a clinical study, adults taking Xywav were compared with people taking a placebo. (A placebo is a treatment with no active drug).

At the beginning of the study, people with narcolepsy took increasing dosages of Xywav for up to 12 weeks, until they reached their correct dosage. Any other medications taken to treat cataplexy were stopped at this time. After this 12-week period, people were given a consistent dose of Xywav for an additional 2 weeks. Then, for an additional 2 weeks, people either continued taking Xywav or took a placebo.

In this study, the average weekly number of cataplexy attacks changed from:

  • 8.9 attacks per week to 9 attacks per week in people who took Xywav throughout the study
  • 7.2 attacks per week to 18.7 attacks per week in people who switched to a placebo at the end of the study

Xywav for excessive daytime sleepiness in people with narcolepsy

Xywav is approved to treat excessive daytime sleepiness (EDS) in adults and children ages 7 years and older with narcolepsy. EDS is a strong feeling of sleepiness that may occur suddenly while you’re awake. Everyone who has narcolepsy experiences EDS.

EDS can make you feel consistently sleepy or tired. This may occur even if you’ve slept well the night before. And when you aren’t experiencing EDS, you’re able to be as attentive and aware as someone without narcolepsy.

Effectiveness for excessive daytime sleepiness in people with narcolepsy

Xywav has been effective in treating EDS in people with narcolepsy.

In a clinical study, adults taking Xywav were compared with people taking a placebo. (A placebo is a treatment with no active drug).

At the beginning of the study, people with narcolepsy took increasing dosages of Xywav for up to 12 weeks, until they reached their correct dosage. Any other medications taken to treat cataplexy were stopped at this time.

After this 12-week period, people were given a consistent dose of Xywav for an additional 2 weeks. Then, for an additional 2 weeks, people either continued taking Xywav or took a placebo.

This study used the Epworth Sleepiness Scale (ESS) to measure people’s symptoms of EDS. This score can range from 0 to 24. A higher number means that you’re sleepier during the day. In the study, ESS scores:

  • did not change from 13.6 in people who took Xywav throughout the study
  • increased from 12.6 to 15.6 in people who were taking a placebo at the end of the study

Xywav and children

Xywav is approved for use in children* ages 7 years and older, and adults. The drug can be used to treat cataplexy or excessive daytime sleepiness (EDS) related to narcolepsy.

Clinical studies have not been done to determine if Xywav is effective in children specifically. However, a clinical study has looked at children ages 7 years and older taking Xyrem. Xyrem is a narcolepsy drug that contains sodium oxybate, which is one of Xywav’s active drug ingredients.†

In this study, children took increasing dosages of Xyrem for up to 10 weeks, until they reached their correct dosage. After 10 weeks, children were then given a consistent dose of Xyrem for 2 weeks. After that, for an additional 2 weeks, half of the children continued taking Xyrem. The other half were switched to a placebo. (A placebo is a treatment with no active drug.)

The study showed that the average weekly number of cataplexy attacks changed from:

  • 3.5 attacks per week to 3.8 attacks per week in children who took Xyrem throughout the study
  • 4.7 attacks per week to 21.3 attacks per week in children who took a placebo at the end of the study

This study used the Epworth Sleepiness Scale (ESS) to measure the children’s symptoms of EDS. This score can range from 0 to 24. A higher number means that you’re sleepier during the day. In the study, ESS scores:

  • increased from 8 to 9 in children who took Xyrem throughout the study
  • increased from 11 to 12 in children who took a placebo at the end of the study

If you or your child have questions about Xywav use and effectiveness in children, talk with your child’s doctor.

* Xywav is not recommended for use in children who weigh less than 44 pounds (20 kilograms). For more information, see “Children’s dosage” in the “Xywav dosage” section above.
† For more information about Xyrem, see “What is the difference between Xywav and Xyrem?” in the “Common questions about Xywav” section below.

You should never drink alcohol while taking Xywav. This is because both Xywav and alcohol are central nervous system (CNS) depressants. This means that both substances work to depress (reduce the activity of) your central nervous system. And both of these substances can cause side effects such as:

  • decreased breathing rate
  • decreased heart rate
  • decreased alertness
  • sleepiness

If you drink alcohol while you’re taking Xywav, these side effects may get worse. In some cases, central nervous system (CNS) depression can occur. CNS depression is a rare but very serious side effect that can cause seizures, trouble breathing, or coma. It can also be fatal.

In fact, Xywav has a boxed warning for CNS depression. A boxed warning is the most serious warnings from the FDA. It alerts doctors and patients about drug effects that may be dangerous. For more information, see the “Xywav precautions” section below.

If you drink alcohol and you have questions or concerns about your alcohol use while taking Xywav, talk with your doctor.

Xywav can interact with several other medications. The drug isn’t known to interact with supplements or foods.

Different interactions can cause different effects. For instance, some interactions can interfere with how well a drug works. Other interactions can increase side effects or make them more severe.

Xywav and other medications

Below are some medications that can interact with Xywav. This article does not contain all drugs that may interact with Xywav.

Before taking Xywav, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Xywav and divalproex sodium

Taking Xywav with divalproex sodium (a drug used to treat seizures) may cause you to have too much Xywav in your body. This can increase your risk for serious side effects from Xywav. These side effects may include trouble breathing or decreased alertness.

If you’re taking divalproex sodium, your doctor may recommend starting Xywav at a lower dosage than usual. This lower dosage helps reduce your risk for these serious side effects.

Or if you’re taking Xywav and you’ll start taking divalproex sodium, your doctor may decrease your dosage of Xywav by 20%. This also reduces your risk for developing serious side effects.

Be sure to talk with your doctor about any other medications that you’re taking before starting Xywav.

Xywav and other CNS depressants

Xywav belongs to a group of drugs called central nervous system (CNS) depressants. These types of drugs work to depress (reduce the activity of) your central nervous system. CNS depressants can cause side effects, such as:

Taking Xywav along with other CNS depressants (especially without consulting your doctor) increases your risk for these side effects. Doing this also increases your risk for CNS depression. This is a serious side effect that can cause seizures, trouble breathing, or coma. CNS depression can even be fatal.

In fact, Xywav has a boxed warning for CNS depression. A boxed warning is the most serious warning from the FDA. For more information, see the “Xywav side effects” section above.

For these reasons, it’s very important to discuss any other medications you take with your doctor before you start taking Xywav. Your doctor can help determine your risk for CNS depression. They can also help you determine whether you’re taking any CNS depressants.

Certain CNS depressants should not be used with Xywav. This is because if taken with Xywav, these drugs cause a high risk for CNS depression. These CNS depressants include:

  • Sleep medications. Examples include:
    • Rozerem (Ramelteon)
  • Benzodiazepines, which are drugs that may be used to treat certain mood and sleep disorders. Examples include:
  • Barbiturates, which are drugs that may also be used to treat certain mood and sleep disorders. Examples include:
    • secobarbital (Seconal)

Note: Alcohol is also a CNS depressant and should not be used with Xywav. See the “Xywav and alcohol” section above for details.

Below are some examples of other types of drugs that may also be CNS depressants. Your doctor will help determine if it’s safe for you to take these medications with Xywav:

If you take any of these medications, or other CNS depressants, make sure to talk with your doctor before you start taking Xywav.

Xywav and herbs and supplements

There aren’t any herbs or supplements that have been specifically reported to interact with Xywav. However, you should still check with your doctor or pharmacist before using any of these products while taking Xywav.

Xywav and foods

There aren’t any foods that have been specifically reported to interact with Xywav. If you have any questions about eating certain foods with Xywav, talk with your doctor.

As with all medications, the cost of Xywav can vary. To find current prices for Xywav in your area, check out WellRx.com.

The cost you find on WellRx.com is what you may pay without insurance. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.

Keep in mind that you may be able to get a 90-day supply of Xywav. If approved by your insurance company, getting a 90-day supply of the drug could reduce your number of orders from the pharmacy and help lower the cost. If you’re interested in this option, check with your doctor or your insurance company.

Keep in mind that Xywav is only available through a Risk Evaluation Mitigation Strategy (REMS) program. This program helps make sure that you and your doctor are aware of the risks associated with the drug. But this means that only certain doctors and pharmacies are able to prescribe and dispense this medication.

In fact, Xywav is dispensed through the Certified Pharmacy. This is the only pharmacy in the United States permitted to fill Xywav prescriptions and mail them directly to you. Certified Pharmacy pharmacists are specially trained in understanding Xywav and can help you use the drug safely and effectively.

Before approving coverage for Xywav, your insurance company may require you to get prior authorization. This means that your doctor and insurance company will need to communicate about your prescription before the insurance company will cover the drug. The insurance company will review the prior authorization request and decide if the drug will be covered.

If you’re not sure if you’ll need to get prior authorization for Xywav, contact your insurance company.

Financial and insurance assistance

If you need financial support to pay for Xywav, or if you need help understanding your insurance coverage, reach out to your insurance company. They can help you and tell you if any financial assistance options are available.

Generic version

Xywav is not available in a generic form. A generic drug is an exact copy of the active drug in a brand-name medication. Generics tend to cost less than brand-name drugs.

Other drugs are available that can treat narcolepsy symptoms. Some may be a better fit for you than others. If you’re interested in finding an alternative to Xywav, talk with your doctor. They can tell you about other medications that may work well for you.

Note: Some of the drugs listed here are used off-label to treat these specific conditions. Off-label drug use means using a drug for a purpose other than what it’s been approved for by the FDA.

Alternatives for cataplexy or excessive daytime sleepiness in people with narcolepsy

Examples of other drugs that may be used to treat cataplexy or excessive daytime sleepiness (EDS) caused by narcolepsy include:

You should take Xywav according to your doctor’s or healthcare provider’s instructions. This is important because when it’s not taken as prescribed, Xywav can cause tolerance. (Tolerance is when you need to take more medication to have the same effect over time.) It may also cause dependence (when your body needs the drug in order to feel normal). These conditions can each lead to misuse of the drug.

Xywav comes as a solution. Before you take the solution, you’ll dilute it by adding water to it. Then you’ll take the diluted solution by mouth.

The drug is taken in two separate doses. One dose is taken when you go to sleep, and the next dose is taken 2.5 to 4 hours after the first dose.

Diluting your dose

Xywav bottles come with a syringe to measure your doses and containers in which you can dilute the solution. You should dilute both of your Xywav doses before you go to sleep.

To dilute the Xywav solution, start by using the syringe to draw the correct dose of the medication out of the bottle. Place the solution into one of the empty containers provided by the pharmacy. Then add 1/4 cup of water to the solution. After that, prepare your second dose of Xywav the same way.

Once you dilute Xywav, the medication should be taken within 24 hours. If you don’t take the diluted solution within 24 hours of diluting it, you should dispose of the solution. (See the “Xywav expiration, storage, and disposal” section below for how to dispose of the drug safely.)

For more detailed step-by-step instructions about how to prepare and take your Xywav dose, see Xywav’s medication guide.

When to take

Take your first Xywav dose at least 2 hours after you’ve eaten and when you’re getting ready to go to sleep. And you should take your second dose 2.5 to 4 hours after you took the first dose.

Take each dose while sitting in bed or make sure to lie down right after taking each dose. Most people fall asleep within 5 to 15 minutes after taking their dose. And make sure to set an alarm to wake up and take your second Xywav dose 2.5 to 4 hours later.

For at least 6 hours after taking a dose of Xywav, you should avoid activities that could be dangerous to do while you’re sleepy. This includes driving. Make sure to talk with your doctor about when you should take Xywav and any activities to avoid.

To help make sure that you don’t miss a dose, try setting reminders on your phone or using a medication timer.

Taking Xywav with food

Xywav doses shouldn’t be taken with food. And Xywav should always be taken at least 2 hours after eating.

Having food in your stomach may cause your body to absorb less Xywav. This can cause the medication to be less effective in treating your narcolepsy symptoms.

Xywav is approved to treat the following narcolepsy symptoms:

  • cataplexy, which refers to sudden, brief episodes of muscle weakness or paralysis that occur while you’re awake
  • excessive daytime sleepiness (EDS), which is a strong feeling of sleepiness that may occur suddenly while you’re awake

Xywav is a central nervous system (CNS) depressant. These types of drugs work to depress (reduce the activity of) the CNS. Although it’s not known exactly how Xywav works, it’s thought to work on certain neurotransmitters (brain chemicals) to increase the amount of time you spend in deep sleep while you’re resting. By improving your sleep, the drug can help reduce your EDS or cataplexy.

How long does it take to work?

Xywav works very quickly to make you sleepy. Most people fall asleep 5 to 15 minutes after taking Xywav.

It’s not known if Xywav is safe to take during pregnancy. In animal studies, sodium oxybate given to pregnant females increased the risk of stillbirth and caused decreased growth in offspring. (Sodium oxybate is one of Xywav’s active drug ingredients.)

Keep in mind that animal studies don’t always predict what will happen in people. But due to the risks seen in animal studies, be sure to tell your doctor if you’re pregnant or planning to become pregnant while taking Xywav. They may recommend a medication other than Xywav to treat your narcolepsy symptoms.

It’s not known if Xywav is safe to take during pregnancy. If you’re sexually active and you or your partner can become pregnant, talk with your doctor about your birth control needs while you’re using Xywav.

For more information about taking Xywav during pregnancy, see the “Xywav and pregnancy” section above.

It’s not known if Xywav is safe to take while breastfeeding. One of Xywav’s active drug ingredients, sodium oxybate, does pass into breast milk. This means that a breastfed child may be exposed to the drug. However, it’s not known what effects Xywav may have on a breastfed child.

If you’re breastfeeding, talk with your doctor before you start taking Xywav. They may recommend a medication other than Xywav to treat your narcolepsy symptoms while you’re breastfeeding.

Here are answers to some frequently asked questions about Xywav.

Will Xywav cure narcolepsy?

No, Xywav won’t cure narcolepsy. In fact, there’s currently no known cure for narcolepsy. Instead, this medication works to reduce excessive daytime sleepiness (EDS) and cataplexy caused by narcolepsy. Xywav is meant to be used long term to reduce these symptoms.

It’s not known exactly how Xywav works. But, it might work on certain neurotransmitters (brain chemicals) to increase the amount of deep sleep you get while you’re resting. And by improving your sleep, Xywav may reduce your EDS or cataplexy.

If you have questions about what to expect from Xywav treatment, talk with your doctor.

Can I take Xywav if I have sleep apnea or other breathing problems?

In most cases, your doctor can prescribe Xywav for you even if you have sleep apnea or other breathing problems. However, these conditions may increase your risk for breathing problems while taking Xywav.

It’s not known how many people taking Xywav in clinical studies had breathing problems. However, in clinical studies of people with sleep apnea who took Xyrem, the drug was safe for most people. Xyrem is a narcolepsy drug that contains sodium oxybate, which is one of Xywav’s active drug ingredients. So it’s thought that Xywav is similarly safe for people with sleep apnea.

For more information about breathing problems in clinical studies of Xywav and Xyrem, see the “Xywav side effects” section above.

If you have a history of breathing problems or sleep apnea, be sure to tell your doctor before you start taking Xywav. These conditions may increase your risk for breathing problems while you’re taking Xywav. Your doctor may monitor you more often than usual for symptoms of decreased oxygen. Or your doctor may recommend a different medication to treat your narcolepsy.

Could Xywav appear on a drug test?

It’s possible that Xywav may cause you to have a positive result on a drug test. This is because Xywav contains sodium oxybate, which is a form of gamma-hydroxybutyrate (GHB). And GHB is an illegal drug.

However, not all drug tests check for GHB. If you need to take a drug test, bring a copy of your prescription with you. As long as you have proof that you have a prescription for Xywav, a positive drug test result for GHB shouldn’t cause problems for you.

If you’re concerned about Xywav appearing on a drug test, talk with your doctor. They may be able to provide a letter about your Xywav treatment, which you could show as proof that you’re taking the drug for a legal medical use.

Can I drive while taking Xywav?

Maybe, but you should not drive while you’re taking Xywav until you know how the drug affects you. Also, for at least 6 hours after you take a dose of Xywav, avoid driving and other activities that could be dangerous to do while you’re sleepy.

This is important because Xywav can cause drowsiness, decreased alertness, and trouble concentrating. And these side effects can be very dangerous if they occur while you’re driving.

If you have concerns about not being able to drive while taking Xywav, talk to your doctor. And make sure to talk with your doctor about when to take your Xywav doses and what activities are safe for you afterward.

What is the difference between Xywav and Xyrem?

Xywav and Xyrem are different in a few ways. Both drugs are used to treat cataplexy and excessive daytime sleepiness (EDS) caused by narcolepsy. And both drugs contain the active drug ingredient sodium oxybate.

In addition to sodium oxybate, Xywav also contains the active drug ingredients calcium oxybate, magnesium oxybate, and potassium oxybates.

However, Xywav contains 92% less sodium (salt) than Xyrem does. Since Xywav is low-sodium, it’s generally a safer option for people who are limiting their salt intake. When a drug is higher in sodium, like Xyrem, people who need to limit their salt intake might not be able to take the drug. This includes people with certain conditions, such as hypertension (high blood pressure), heart conditions, or kidney disease.

Xywav dosage is also slightly different from Xyrem dosage. People taking Xyrem should split their two doses equally. For example, if you take 3 grams (g) of Xyrem at bedtime, your second dose should also be 3 g. In comparison, Xywav can be taken as two unequal doses, if prescribed by your doctor. In some cases, the drug may even be more effective when taken in unequal doses.

If you have questions about differences between Xywav and Xyrem, talk with your doctor or pharmacist.

This drug comes with several precautions.

FDA warnings

This drug has boxed warnings. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that may be dangerous.

  • Central nervous system (CNS) depression. Xywav belongs to a group of drugs called CNS depressants. These types of drugs may slow your breathing rate, decrease your blood pressure, or make you feel sleepy. If you take Xywav along with other CNS depressants, you may develop CNS depression. (With CNS depression, the body’s nervous system functions slow down. This can cause symptoms such as seizures, trouble breathing, or coma. CNS depression can even be fatal.) Certain pain medications and some antidepressant medications may be CNS depressants. Also, alcohol is a CNS depressant. It’s important to talk with your doctor about any other medications you’re taking before starting Xywav treatment. Your doctor can determine whether any of your current medications are CNS depressants. They can also discuss your risk for CNS depression. For more information about CNS depression, see the “Xywav side effects” section above.
  • Misuse. Xywav is a controlled substance, meaning the drug is regulated by the government to prevent possible misuse. Misusing CNS depressant drugs such as Xywav may cause serious side effects, especially if taken with other CNS depressants. These side effects can include seizures, trouble breathing, coma, or even death. Due to this risk of side effects, the FDA requires that Xywav be prescribed only through a Risk Evaluation Mitigation Strategy (REMS) program. This program helps make sure that you and your doctor are aware of your risks related to taking the drug, including your risk for misusing Xywav and for CNS depression. For more information about misuse of Xywav, see the “Xywav side effects” section above.

Other precautions

Before taking Xywav, talk with your doctor about your health history. Xywav may not be right for you if you have certain medical conditions or other factors affecting your health. These include:

  • Depression or suicidal thoughts or actions. Xywav can cause depression or suicidal thoughts or behaviors. If you have a history of depression or suicidal thoughts or actions, taking Xywav may make these feelings worse. Be sure to tell your doctor about any depression or suicidal thoughts or behaviors you’ve experienced. They may monitor you more often than usual for symptoms of depression or suicidal thoughts while you’re taking Xywav. Depending on your mental health history, your doctor may recommend a medication other than Xywav to treat your narcolepsy symptoms.
  • Behavioral conditions such as anxiety or confusion. If you have certain behavioral conditions, such as anxiety or confusion, taking Xywav may make these symptoms worse. This is because Xywav may also cause you to feel anxious or confused, or experience other side effects like hallucinations (seeing or hearing things that are not actually there) or feeling more suspicious than usual (paranoia). Talk with your doctor about any behavioral conditions you have. Your doctor may monitor you more often than usual while you take Xywav. Or they may recommend a medication other than Xywav to treat your narcolepsy symptoms.
  • Liver problems. If you have liver problems, your doctor may recommend a lower dose of Xywav than usual for you. This is because if you have liver problems, your body may not break down Xywav as quickly as usual. This can cause the drug to build up in your body. Be sure to talk with your doctor about any liver problems that you have. They can determine if Xywav is safe for you to take.
  • Sleep apnea. Sleep apnea (stopping and restarting breathing while you sleep) can decrease your oxygen levels. And taking Xywav can cause a decreased breathing rate, which can also decrease your oxygen levels. So taking Xywav if you have sleep apnea may cause you to get even less oxygen. Talk with your doctor if you have sleep apnea. They may monitor your oxygen levels more often than usual while you’re taking Xywav.
  • Trouble breathing or lung problems. Xywav may cause a decreased breathing rate. If you have trouble breathing or any lung conditions, you may already have a decreased breathing rate. Xywav can make this worse. Talk to your doctor about any breathing or lung problems that you have. They may monitor your oxygen levels more often than usual while you’re taking Xywav.
  • A rare brain disorder called succinic semialdehyde dehydrogenase deficiency. If you have succinic semialdehyde dehydrogenase deficiency, you should never take Xywav. This is because this disorder may prevent your body from breaking down a brain chemical called gamma aminobutyric acid (GABA). Xywav is related to GABA, and taking Xywav may cause too much of the chemical to build up. If you have succinic semialdehyde dehydrogenase deficiency, talk with your doctor about a treatment other than Xywav for your narcolepsy symptoms.
  • Allergic reaction. If you’ve had an allergic reaction to Xywav or any of its ingredients, you shouldn’t take Xywav. Ask your doctor what other medications may be better options for you.
  • Pregnancy. It isn’t known if Xywav is safe to take during pregnancy. For more information, see the “Xywav and pregnancy” section above.
  • Breastfeeding. It isn’t known if Xywav is safe to take while breastfeeding. For more information, see the “Xywav and breastfeeding” section above.

Note: For more information about the potential negative effects of Xywav, see the “Xywav side effects” section above.

Using more than the recommended dosage of Xywav can lead to serious side effects. Do not use more Xywav than your doctor recommends.

No overdoses occurred in people who took Xywav in clinical studies. However, two overdoses occurred in clinical studies of Xyrem, which is a narcolepsy drug that contains sodium oxybate (one of Xywav’s active drug ingredients):

  • In one case, a person took more than 15 times the recommended dose of Xyrem. Although this person became unconscious and had trouble breathing, they recovered without long-term effects.
  • In the other case, the person died after taking more than the recommended amount of Xyrem along with many other drugs.

Overdose symptoms

The following symptoms were reported from overdoses that occurred after people illegally used gamma-hydroxybutyrate (GHB). One of Xywav’s active drug ingredients, sodium oxybate, is a form of GHB. GHB is a substance that’s illegal and has a high potential for misuse. (For more information, see the “What is Xywav” section above.)

Symptoms of an overdose can include:

  • confusion
  • agitation
  • vomiting
  • sweating
  • headache
  • blurry vision
  • coma
  • seizures
  • decreased breathing
  • decreased heart rate
  • unconsciousness

What to do in case of overdose

If you think you’ve taken too much of this drug, call your doctor. You can also call the American Association of Poison Control Centers at 800-222-1222 or use their online tool. But if your symptoms are severe, call 911 or your local emergency number, or go to the nearest emergency room right away.

There haven’t been clinical studies on whether Xywav can cause drug dependence. (With dependence, your body needs the drug in order for you to feel normal.) So it’s not known how many people in clinical trials may have experienced dependence while taking the drug.

It’s also not known if people in clinical trials may have had withdrawal symptoms after stopping Xywav. (Withdrawal refers to unpleasant symptoms that occur when you stop taking a drug that your body has become dependent upon.)

However, anxiety and insomnia (trouble sleeping) were reported after people stopped taking Xywav in clinical trials.* And in case reports† of people who’ve stopped illegal use of GHB, withdrawal symptoms included anxiety and insomnia in some cases. GHB is a substance that’s illegal and has a high potential for misuse. One of Xywav’s active drug ingredients, sodium oxybate, is a form of GHB.

In case reports of people who stopped illegal GHB use, withdrawal symptoms lasted anywhere from 3 days to 14 days. In addition to anxiety and insomnia, symptoms also included:

Withdrawal and dependence can lead to misuse of Xywav. And misuse of Xywav is associated with seizures, trouble breathing, coma, and death. In fact, Xywav has a boxed warning for misuse. (A boxed warning is the most serious warning from the FDA. For more information, see the “Xywav side effects” section above.)

Xywav itself is a Schedule Three (III) controlled substance. This means that although there are risks of misuse, tolerance, and dependence, the drug does have an approved medical use.

If you have questions about withdrawal and dependence while taking Xywav, talk with your doctor. And before you stop taking Xywav, be sure to talk with your doctor. They may slowly reduce your dosage of the drug so that your body can adjust to the change. Slowly reducing your dosage decreases your risk for withdrawal symptoms.

* These side effects were also reported in clinical trials of Xyrem, which is a different drug that’s also used to treat cataplexy and excessive daytime sleepiness (EDS) caused by narcolepsy. Xyrem contains sodium oxybate, which is one of the active drug ingredients in Xywav.
† A case report is a record of an individual’s medical experience. Unlike clinical trials, case reports don’t provide data that’s reliable enough to be used to help the public make informed decisions about using a drug.

When you get Xywav from the pharmacy, the pharmacist will add an expiration date to the label on the bottle. This date is typically 1 year from the date they dispensed the medication.

The expiration date helps guarantee that the medication is effective during this time. The current stance of the Food and Drug Administration (FDA) is to avoid using expired medications. If you have unused medication that has gone past the expiration date, talk to your pharmacist about whether you might still be able to use it.

Storage

How long a medication remains good can depend on many factors, including how and where you store the medication.

Xywav solution should be stored at a room temperature of 68°CF to 77°F (20°C to 25°C). If necessary, you may store the drug at a temperature of 59°F to 86°F (15°C to 30°C) for a short period of time. It should be kept in a tightly sealed container.

Note: Once you dilute (add a certain amount of water to) Xywav, the medication should be taken within 24 hours. If you don’t take your dose within 24 hours of diluting it, you should dispose of the solution.

Disposal

If you no longer need to take Xywav and have leftover medication, it’s important to dispose of it safely. This helps prevent others, including children and pets, from taking the drug by accident. It also helps keep the drug from harming the environment.

The recommended way to dispose of unused Xywav is to pour it down a sink drain.

This article provides several useful tips on medication disposal. You can also ask your pharmacist for information about how to dispose of your medication.

Note: Once you dilute Xywav, the medication should be taken within 24 hours. If you don’t take the diluted solution within 24 hours of diluting it, you should dispose of the solution.

Disclaimer: Medical News Today 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 other 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.