Xywav (Calcium, Magnesium, Potassium, and Sodium Oxybates) - Oral

What Is Xywav?

Xywav is a central nervous system (CNS) depressant that treats sleeping disorders in people 7 years of age and older.

Xywav is a combination of different oxybate molecules: calcium, magnesium, potassium, and sodium oxybates. The molecule oxybate is also known as gamma-hydroxybutyrate, or GHB, and is the active ingredient in Xywav. It is not known exactly how GHB affects sleep. However, the most common theory is that it acts on GABA receptors in the brain, which help regulate sleep.

GHB by itself is a Schedule I drug and has no legal use. Xywav is a Schedule III controlled substance, which means it is tracked and regulated more carefully than a normal prescription drug. A Schedule III class for a drug also means that there is moderate to low potential for physical or psychological dependence. Xywav has its own monitoring program called a REMS program. You will need to get it from a pharmacy that is certified to dispense it, rather than a local pharmacy.

What Is Xywav Used For?

Xywav is approved for two indications: daytime sleepiness and cataplexy in narcolepsy, and idiopathic hypersomnia.

Individuals with narcolepsy may have any number of four symptoms: excessive daytime sleepiness (EDS), cataplexy, hallucinations, and sleep paralysis. Xywav is approved to treat two of these: EDS and cataplexy. Cataplexy is the sudden onset of weak or paralyzed muscles. A person may lose control of their muscles and collapse in any given situation.

Idiopathic hypersomnia (IH) causes excessive sleepiness during the day even after a good night's sleep. Like narcolepsy, it can be dangerous because the sleepiness can strike at any time, like while driving or working. However, IH does not include cataplexy.

How to Take Xywav

Xywav is taken by mouth two times per night, once at bedtime and again two and a half to four hours later. The dose will likely be started on the lower end and may be increased by your healthcare provider based on how much it’s helping you and how well you’re tolerating it.

Prepare both doses of Xywav prior to bedtime. Each dose is prepared by adding about ¼ cup (60 milliliters) of water to Xywav in the empty containers provided. Once prepared, doses need to be consumed within 24 hours. Take Xywav while you’re in bed, and lie down right after you take it. It may cause you to fall asleep abruptly without first feeling drowsy.

You may need to set an alarm to wake yourself up for your second dose each night. You can keep Xywav by your bed so you don’t have to get up to take the dose. If the second dose is missed, skip it and don’t take Xywav again until the next night. Never take two doses at one time.

Storage

Store Xywav at room temperature (68 degrees to 77 degrees F). Once you prepare your Xywav dose, it needs to be taken within 24 hours, so only prepare one night’s worth (two doses) at a time. If you need to waste a dose, it is safe to dispose of Xywav down the drain.

When traveling, keep Xywav packed in your carry-on luggage with the lid on tight. Make sure to bring your prescription information and notify TSA personnel when you’re going through security that you have the drug with you.

What Are the Side Effects of Xywav?

This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the FDA at fda.gov/medwatch or 1-800-FDA-1088.

Common Side Effects

The following are some of the more common side effects of Xywav. If you notice these side effects and think they are severe or do not go away you should notify your healthcare provider:

• Headache
• Nausea
• Dizziness
• Decreased appetite
• Abnormal dreams
• Night sweats
  

Severe Side Effects

Notify your healthcare provider right away if you notice these side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

• CNS depression. Significant respiratory depression (breathing problems) and a lowered level of consciousness have occurred in some people taking Xywav, as it is a CNS depressant. Wait until you know how Xywav affects you before you drive or operate other machinery.
• Abuse and misuse. The active ingredient in Xywav, oxybate or GHB, does have abuse and misuse potential due to its rapid onset of action and amnestic features, or its ability to cause some short-term memory loss. GHB is a schedule I (illegal) drug that is sometimes used on victims of assault–a “date-rape drug”. This is why it is important to avoid use with alcohol and to be cautious in individuals who may have a history of drug abuse or misuse.
• Neuropsychiatric reactions. Some adults have experienced hallucinations, paranoia, aggression, or agitation while on Xywav. Make sure to let your healthcare provider know as soon as possible if you think Xywav may be affecting you in these ways.
  

Long-Term Side Effects

As long as you continue to take Xywav exactly as prescribed, no side effects are known to emerge after long-term use compared to the shorter-term effects listed above.

Dosage: How Much Xywav Should I Take?

Modifications

Treatment with Xywav may need to be modified for certain populations, depending on circumstances such as pregnancy, age, and other health conditions.

Pregnancy

There is not sufficient data regarding the safety of taking Xywav while pregnant. The benefit of treating narcolepsy or idiopathic hypersomnia should be weighed against any risk that Xywav may pose to a pregnancy.

Breastfeeding

GHB, the active ingredient in Xywav, is excreted in human milk. How much of the drug that may get into breast milk or the effect it may have on a baby is not well understood. The need for Xywav should be considered and weighed against any potential risk to the baby.

Children

Xywav has been established as safe and effective to treat excessive daytime sleepiness and cataplexy in children with narcolepsy at least 7 years old and older. This has not been established in children younger than 7.

Older Adults

Clinical trials of Xywav did not have sufficient numbers of individuals over age 65 to say with much confidence if they respond differently to Xywav than younger adults do. Older adults had a higher frequency of headaches, and slightly more older adults people discontinued the drug than younger people. Therefore, older adults should be started at a lower dose, considering other possible factors like liver or kidney function.

Liver Disease

If you have liver disease, you will likely start at a lower dose of Xywav, as you may be exposed to more drug if you have a lower liver function.

Missed Dose

Since your second dose of Xywav will be in the middle of the night, you may miss a dose sometimes. Set an alarm to wake yourself up for this second dose, but if you miss it, just skip that dose and take Xywav as usual the next night. Never take two doses at one time.

Overdose: What Happens If I Take Too Much Xywav?

Take Xywav exactly as prescribed by your healthcare provider. Information about symptoms associated with Xywav overdose mostly come from reports of illegal use of GHB, which means alcohol is often a factor as well. Symptoms may include varying degrees of low consciousness, and may quickly change to an agitated or combative state. Vomiting, blurred vision, seizures, and trouble breathing are also potential signs and symptoms.

Precautions

What Are Reasons I Shouldn't Take Xywav?

You should not take Xywav if you:

• Also take sedative hypnotics
• Drink alcohol
• Have a condition called succinic semialdehyde dehydrogenase deficiency, a rare metabolism disorder
  

What Other Medications Interact With Xywav?

There are a few important interactions between Xywav and other drugs.

• Alcohol should be completely avoided while on Xywav. Like Xywav, alcohol is a CNS depressant and can increase the risk for respiratory depression (breathing problems), low blood pressure, and extreme sedation (sleepiness) or death.
• Other CNS depressants like benzodiazepines, narcotic painkillers, sedating antipsychotics or antidepressants, muscle relaxers, and sedatives like sleeping pills can all add to the effects that Xywav produces and increase the risk of respiratory depression, low blood pressure, and extreme sedation or death.
• Depakote (divalproex) is an anti-seizure medication that can also cause CNS depression. When starting divalproex in people taking Xywav, the dose of Xywav should be lowered. If you are already on divalproex, a lower starting dose of Xywav is recommended.

What Medications Are Similar?

Other medications used to treat narcolepsy include:

• Xyrem (sodium oxybate) is the only other medication with oxybate as the active ingredient. It contains only sodium oxybate, not a mix of other oxybates like Xywav does. Therefore it contains a higher amount of sodium per dose.
• Wakix (pitolisant) is a histamine antagonist designed to improve individuals’ time awake. It is approved for excessive daytime sleepiness in narcolepsy.
• Sunosi (solriamfetol) is also approved for excessive daytime sleepiness in narcolepsy. It aims to improve wakefulness by regulating certain chemicals in the brain including dopamine and norepinephrine.

This list is NOT a list of drugs recommended to take with Xywav. In fact, you should not take these drugs together. Ask your pharmacist or a healthcare provider if you have questions.

How Can I Stay Healthy While Taking Xywav?

Narcolepsy is thought to be caused in part by a low amount of a substance in your brain called hypocretin. Hypocretin promotes wakefulness and maintains your normal muscle functioning. Unfortunately, there is no cure for narcolepsy, but some behavior changes and medications can help.

The loss of control you may feel when you have narcolepsy, especially with the loss of muscle control that comes with cataplexy, can feel dangerous and downright scary. It can be frustrating to try to maintain a career and relationships while struggling with narcolepsy. Educate your friends and family about the condition to give them the opportunity to best support you in dealing with it.

Avoiding substances that can either increase or decrease your energy level (e.g., alcohol, allergy medicines, caffeine) can help improve narcolepsy symptoms. So can medications like Xywav that are focused on improving your time asleep and helping you stay asleep at night. Further treatments are being developed and studied in clinical trials to continue identifying new ways to help people with narcolepsy and idiopathic hypersomnia.