Xywav (calcium/magnesium/potassium/sodium oxybates) is a prescription drug used to treat certain sleep problems. Xywav can cause side effects that range from mild to serious. Examples include nausea, dizziness, and headache.

Specifically, Xywav is used in adults and certain children to treat:

The active ingredients in Xywav are calcium, magnesium, potassium, and sodium oxybates. The drug comes as a liquid that you swallow.

Keep reading to learn about common, mild, and serious side effects Xywav can cause. For a general overview of the drug, including details about its uses, see this article.

Xywav has boxed warnings. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Side effects explained” section.

Below are just a few of the more common side effects reported by people who took Xywav in studies. Side effects can vary depending on what condition the drug is being used to treat.

More common side effects in adults taking Xywav for IH include:

More common side effects in people taking Xywav for EDS or cataplexy include:

Mild side effects have been reported with Xywav. These include:

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist. And do not stop taking Xywav unless your doctor recommends it.

Xywav may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

Serious side effects have been reported with Xywav. These include:

If you develop serious side effects while taking Xywav, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* To learn more about this side effect, see the “Side effects explained” section.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Xywav, visit MedWatch.

Allergic reaction

For some people, Xywav can cause an allergic reaction. But this side effect wasn’t reported in the drug’s studies.

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 difficulty 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.

Learn more about some of the side effects Xywav may cause.

Boxed warning: Risk of central nervous system (CNS) depression

Xywav has a boxed warning for the risk of CNS depression. This was an uncommon side effect reported in the drug’s studies. CNS depression may cause symptoms such as:

In some cases, it can even lead to coma and death.

Factors that can increase the risk of CNS depression when taking this drug include:

What might help

If you have symptoms of CNS depression during Xywav treatment, call 911 or your local emergency number right away. Seek immediate medical attention for these symptoms, as they may be life threatening.

Boxed warning: Risk of misuse

Xywav has a boxed warning for the risk of misuse (often called abuse). This was an uncommon side effect reported in the drug’s studies.

With misuse, a person takes a drug in a way or for a reason other than how or why it was prescribed. Examples of misuse include taking the drug more often or at higher doses than recommended by your doctor.

Due to the risk of misuse, Xywav is a controlled substance in the United States. This means the drug has an approved medical use but may be misused for other purposes. It also means government agencies, doctors, and pharmacists pay close attention to how it’s prescribed and used.

Due to the risks of CNS depression and misuse, the drug is available only through the Xywav and Xyrem risk evaluation and mitigation strategy (REMS) program. The FDA requires REMS programs for certain drugs to help ensure they’re safely prescribed. To find out more about the Xywav REMS program, visit the website or call 866-997-3688.

To prevent others from misusing Xywav, secure it in a safe place. It’s illegal and dangerous to sell or give Xywav to others.

You should take Xywav only as your doctor has prescribed. Misuse increases the risk of overdose, which can lead to breathing difficulties, coma, and even death.

What might help

If you have a history of substance use disorder or concerns about your risk of misuse, talk with your doctor or pharmacist. They can help you decide if Xywav is right for you.

Mental health problems

Mental health problemswere a common side effect reported in studies of Xywav and may cause symptoms such as:

Having a history of depression or other mental health conditions can increase the risk of mental health problems when taking Xywav.

What might help

If you have mental health symptoms during Xywav treatment, talk with your doctor right away. They’ll likely recommend an office visit to discuss your symptoms. If your symptoms are severe or life threatening, seek emergency medical care or call 911 or your local emergency number right away.

Help is out there

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

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 are not in the same household, stay on the phone with them until help arrives.

Below is important information you should consider before taking Xywav.

Boxed warnings: Risks of CNS depression and misuse

Xywav has boxed warnings. A boxed warning is the most serious warning from the FDA. For details, see the “Side effects explained” section.

Other warnings

Xywav can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Xywav is a good treatment option for you.

Talk with your doctor about your health history before starting Xywav. Be sure to tell them if any of the following factors apply to you:

  • sleep apnea
  • liver problems
  • lung problems
  • mental health problems or history of suicidal thoughts or actions
  • history of substance use disorder
  • a rare condition called succinic semialdehyde dehydrogenase deficiency
  • previous allergic reaction to Xywav
  • taking other prescription or over-the-counter medications, vitamins, supplements, or herbs
  • pregnancy
  • breastfeeding
  • alcohol or illegal drug use

Taking Xywav can lead to physical dependence. This is when your body gets used to a drug and needs it for you to function as usual.

If you suddenly stop taking Xywav, you may experience withdrawal symptoms. (These are side effects that can occur when you stop taking a drug your body has become dependent on).

Examples of withdrawal symptoms with Xywav include:

  • insomnia
  • anxiety
  • hallucinations

Before stopping your Xywav treatment, your doctor may lower your dosage slowly over time. This can help reduce your risk of withdrawal symptoms after you stop treatment. If you do have withdrawal symptoms, talk with your doctor. They can recommend ways to help ease them.

Keeping track of side effects

During your Xywav treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking a new drug or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Sharing notes with your doctor will help them learn more about how Xywav affects you. They can then use this information to adjust your treatment plan if needed.

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.