Xywav™ (calcium, magnesium, potassium, and sodium oxybates)

Xywav™ is approved by the U.S. Food and Drug Administration (FDA) for the treatment of narcolepsy. Xywav (calcium, magnesium, potassium, and sodium oxybates) has 92 percent less sodium per dose than the current standard of care, Xyrem (sodium oxybate). This lower sodium content could help reduce the risk of heart disease.1

Xywav is approved for use in people who are at least 7 years old and have narcolepsy. Specifically, those with cataplexy (sudden loss of muscle tone) or excessive daytime sleepiness.1

Xywav is the first new narcolepsy drug in 15 years approved to treat both cataplexy and excessive daytime sleepiness. It is in the same family of drugs as Xyrem. Both are made by the same company.1

What are the ingredients in Xywav?

The active ingredients in Xywav include:1

  • Calcium oxybate
  • Magnesium oxybate
  • Potassium oxybate
  • Sodium oxybate (gamma-hydroxybutyrate)

How does Xywav work?

Xywav is a central nervous system (CNS) depressant. The exact way Xywav works in narcolepsy is unknown. The ingredients in Xywav are made by the body when it breaks down GABA, a chemical that is produced naturally in the brain. GABA produces a calming effect that can help with feelings of anxiety, stress, and fear. GABA also plays a role in sleep-wake cycles.2,3

What are the possible side effects of Xywav?

The most common side effects of Xywav in adults include:1

  • Headache or dizziness
  • Nausea, vomiting, or decreased appetite
  • Diarrhea
  • Sweating
  • Parasomnia (abnormal dreams, abnormal REM sleep, sleep paralysis, sleep talking, and other abnormal sleep-related events)
  • Anxiety

The most common side effects of Xywav in children include:1

  • Headache or dizziness
  • Nausea or vomiting
  • Decreased appetite or weight loss
  • Bedwetting
  • Sleepwalking

Xywav has a boxed warning, the strictest warning from the FDA. It has this warning for central nervous system (CNS) depression and abuse and misuse.1

These are not all the possible side effects of Xywav. Talk to your doctor about what to expect when taking Xywav. You also should call your doctor if you have any changes that concern you when taking Xywav.

Things to know about Xywav

Because of the potential risks of CNS depression and abuse and misuse, Xywav is only available through a restricted program called a Risk Evaluation and Mitigation Strategy (REMS).1

Under this REMS program, strict safety measures are put in place. Prescribers and people taking the drug are required to enroll in this program. For example, Xywav can only be prescribed by a certified prescriber, and it can only be dispensed by a certified pharmacy to an enrolled person. It is not available in retail pharmacies.1

Serious side effects and medical problems can occur if Xywav is taken with any other CNS depressants like:1

  • Opioids
  • Benzodiazepines
  • Certain antidepressants
  • Anti-psychotics
  • Muscle relaxers
  • Alcohol
  • Street drugs
  • Sedating anti-seizure medications

If you are taking any of these, talk with your doctor before starting Xywav. Signs of serious CNS depression include:1

  • Trouble breathing
  • Severe drowsiness
  • Fainting
  • Low blood pressure

Xywav can make a person severely drowsy. People taking Xywav should not do anything that requires them to be fully awake within 6 hours of taking the drug. This includes driving, operating machinery, or flying an airplane. Special considerations may need to be made when it comes to those who are pregnant or elderly.1

Xywav may also cause mood issues including:1

  • Depression
  • Thoughts of suicide
  • Confusion
  • Anxiety

Talk with your doctor if you notice signs of mood changes and seek immediate medical attention if you have thoughts of harming yourself or others.

Before beginning treatment for narcolepsy, tell your doctor about any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs

For more information, read the full prescribing information of Xywav.

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Written by: Casey Hribar | Last reviewed: January 2021