9 Xywav Side Effects You Should Know About

Narcolepsy and idiopathic hypersomnia are health conditions that involve excessive sleepiness during the day. A medication called Xywav is FDA approved to help treat these conditions. It’s a combination of calcium, magnesium, potassium, and sodium oxybates. And it comes as an oral solution that you take at bedtime.

Xywav can help people stay awake during the day and sleep well at night. But like all medications, Xywav has risks. Usually, Xywav side effects are mild and go away on their own. But severe side effects can also occur. Knowing what to watch out for can help keep you safe.

Xywav side effects at a glance

Mild Xywav side effects can often be managed at home. On the other hand, rare but serious side effects may require medical attention.

Mild Xywav side effects include:

• Headache

• Dizziness

• Tiredness

• Decreased appetite

• Nausea and vomiting

• Diarrhea

• Increased sweating

• Dry mouth

• Tremor (shakiness)

• Bed-wetting in children

Serious Xywav side effects include:

• Mood and behavior changes, including anxiety, depression, and hallucinations

• Suicidal thoughts and behaviors

• Slowed breathing and overdose

• Sleepwalking or other unusual activities while asleep (parasomnias)

• Sleep apnea

• Dependence and misuse

Below, we’ll dive deeper into nine Xywav side effects and tips on how to manage them.

1. Gastrointestinal side effects

Gastrointestinal (GI) side effects, such as nausea, vomiting, and diarrhea, are common with Xywav. These side effects are part of the reason you’ll likely start with a lower dosage of Xywav. Then, if you’re tolerating the medication well, your prescriber may increase your dosage.

Since Xywav is typically taken before bedtime, you’ll likely fall asleep before any nausea or GI discomfort hits. But if you are experiencing nausea, some strategies that may help are staying hydrated and eating smaller (but more frequent) meals. For diarrhea, try avoiding fatty, fried, or spicy foods. 

However, if your GI symptoms don’t improve, let your prescriber know. They may recommend over-the-counter (OTC) medications for nausea or diarrhea. If OTC options don’t help, there are prescription medications that may provide a short-term solution. Additionally, your prescriber may consider lowering your Xywav dosage to see if that helps.

2. Headaches

About 1 in 5 people in Xywav clinical studies reported having headaches. Older adults, in particular, are at risk of experiencing this side effect. But there are ways to prevent or manage headaches related to Xywav. Strategies like drinking plenty of water, exercising regularly, and meditating can all potentially help.

It’s important to note that headaches can have several causes, including stress, drinking too much caffeine or alcohol, and not sleeping well. Let your prescriber know if you’re still not sleeping well despite taking Xywav. You can also talk to them about trying OTC pain relievers such as acetaminophen (Tylenol) or ibuprofen (Advil). These medications can provide temporary relief from headaches.

3. Dizziness

Another possible Xywav side effect is dizziness. Since you’ll likely be in bed when you take Xywav, dizziness may not cause problems for you, even if you experience it.

However, if Xywav is causing daytime dizziness, take precautions to avoid falls and injuries. This includes removing any tripping hazards from your walkways, using nonslip mats in your bathrooms, and keeping everyday items on shelves that are easy to reach.

If you experience dizziness with Xywav, drinking water or eating a few bites of food may help. But let your prescriber know if this side effect worsens or doesn’t go away over time.

Good to know: Because Xywav can cause dizziness and decreased alertness, avoid any activities that require focus for at least 6 hours after you take it. This is especially important when you first start taking Xywav, before you know how it affects you. Activities to avoid include driving or climbing a ladder.

4. Decreased appetite

Decreased appetite is another possible Xywav side effect. This may also cause weight loss.

Not eating enough makes it hard to get the nutrients you need to stay healthy and energetic. If you are losing weight or eating less while taking Xywav, let your prescriber know. They may recommend eating smaller meals as often as you can throughout the day. They may also recommend prioritizing items that are nutrient-dense, such as smoothies, nut butters, and avocados. Additionally, they may consider lowering your Xywav dosage or prescribing you a different medication.

5. Mood changes

Some people taking Xywav have reported feeling more irritable, anxious, or depressed. More seriously, hallucinations, confusion, and suicidal thoughts and behaviors have also been reported. 

If you have a history of depression or another mental health condition, make sure to let your prescriber know before you start taking Xywav. They may want to monitor you more closely for mood or behavior changes. And if you notice you feel more depressed, anxious, or confused while taking Xywav, talk to your prescriber right away.

If you or someone you know is having thoughts of suicide, you’re not alone, and help is available. Call the National Suicide Prevention Lifeline at 988, or text “HOME” to 741-741 to reach the Crisis Text Line. 

6. Increased sweating

Xywav can cause increased sweating (hyperhidrosis) in some people. This can happen during the day or at night. If you notice that you’re sweating more than usual while taking Xywav, try using an OTC antiperspirant. And try wearing cool, loose clothing to bed to decrease sweating at night.

Hyperhidrosis usually isn’t dangerous, but it can affect your quality of life. If you’re experiencing increased sweating, let your prescriber know. They may start by ruling out other conditions and medications that could be contributing to the problem. If they think Xywav is the likely cause of your symptoms, they may suggest taking medication to help with sweating, reducing your Xywav dosage, or even stopping treatment entirely.

7. Unusual sleep behaviors

Xywav can cause unusual sleep behaviors, such as sleepwalking, sleep talking, and abnormal dreams. Eating while asleep is also possible. In some cases, you may not be able to remember these events. 

If you find out that you’ve been experiencing unusual sleep behaviors, let your prescriber know right away. Parasomnias, such as sleepwalking, can be dangerous and lead to injury. Your prescriber may recommend lowering your Xywav dosage. Or they may switch you to another medication.

Good to know: It may sound counterintuitive, but Xywav can cause some people to have trouble sleeping at night (insomnia). To help improve your chances of getting a good night’s sleep with Xywav, make sure you have good sleep hygiene habits. This includes having a consistent bedtime routine, keeping your bedroom cool and dark, and exercising in the morning or afternoon. It’s also best to avoid using your phone or watching TV an hour before bedtime.

8. Breathing problems

Xywav is part of a broad group of medications called central nervous system (CNS) depressants. These medications affect your brain function and can cause sleepiness, drowsiness, and confusion. They can also slow down your breathing and even lead to an overdose. This is more likely if you combine or take CNS depressants in a way that’s different from how they’re prescribed.

There are a few precautions you can take to lower your risk of breathing problems, including slowed breathing, and overdose with Xywav. First, let your prescriber know if you have an existing breathing problem, such as sleep apnea, before starting treatment. Having an existing breathing problem may make you more likely to have problems with Xywav. Second, avoid combining Xywav with alcohol and other CNS depressants, such as opioids and benzodiazepines. 

Due to the risk of breathing problems with Xywav, the medication is only obtainable through a Risk Evaluation and Mitigation Strategy (REMS) program. This type of program is put in place by the federal government to monitor and control how certain medications (like Xywav) are prescribed and used.

Good to know: Before starting Xywav, give your prescriber and pharmacist an updated medication list that includes all the prescription and OTC medications you take. This will help them check for drug interactions that can increase your risk of breathing problems.

9. Dependence and misuse

Xywav is a controlled substance. This means that it carries a risk of dependence and misuse. Controlled substances have restrictions on how they’re prescribed and administered. The potential for misuse with Xywav is another reason it’s only available through a REMS program. 

The active ingredient in Xywav is related to a substance called gamma-hydroxybutyrate (GHB). GHB is an illegal drug that carries a risk of misuse. Although Xywav is usually considered safe when taken as prescribed, it may not be the best option if you have a history of substance use disorder.

If you’re prescribed Xywav, carefully follow your prescriber’s instructions on how to take it. If you find yourself taking more Xywav than recommended, talk to your prescriber right away. 

If you or someone you know struggles with substance use, help is available. Call SAMHSA’s National Helpline at 1-800-662-4357 to learn about resources in your area. 

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Written by:

Makaela Premont, PharmD

Makaela Premont, PharmD, is a pharmacist and the founder of uniquelymickie.com, a website dedicated to helping pharmacy students and pharmacists create a life that they enjoy. She received her Doctorate of Pharmacy from the University of South Carolina and is a licensed pharmacist in North Carolina.

Edited by:

Amy B. Gragnolati, PharmD, BCPS

Amy Gragnolati, PharmD, BCPS, is a pharmacy editor for GoodRx. Amy currently holds her pharmacist license in Georgia and California.

Reviewed by:

Daphne Berryhill, RPh

Daphne Berryhill, RPh, has two decades of experience as a clinical pharmacist. She spent most of her career in the Chicago area practicing in-home infusion.

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