The drug was already approved to treat adults and children over the age of 7 years with narcolepsy and cataplexy or excessive daytime sleepiness. This approval marks a new use for the drug.
“Idiopathic hypersomnia is a life-long condition, and the approval of Xywav will be instrumental in providing treatment for symptoms such as excessive sleepiness and difficulty waking, and in effectively managing this debilitating disorder,” Eric Bastings, MD, the deputy director of the Office of Neuroscience at the Center for Drug Evaluation and Research, said in a statement from the FDA.
Bastings added that “a novel indication for Xywav is significant as the FDA has never granted an approval for idiopathic hypersomnia.”
What to Know About Xywav
Xywav is an oral mixture of calcium oxybate, magnesium oxybate, potassium oxybate, and sodium oxybate. Oxybate is another name for gamma-hydroxybutyrate (GHB), which depresses the central nervous system.
GHB is sometimes used illicitly as a “date rape” drug that can easily be slipped into a drink to make someone unconscious.
Xywav is a different version of GHB than another similar drug named Xyrem, which is also made by Jazz Pharmaceuticals.
Xyrem is approved for the treatment of cataplexy and excessive daytime sleepiness. Each dose of Xyrem contains a large amount of sodium—more than the daily recommended level of sodium in the higher doses. Xywav has far less sodium per dose than Xyrem.
Xywav received FDA approval for the treatment of idiopathic hypersomnia after the agency reviewed the data from a clinical study that included 154 adult patients with the condition.
During the trial, the patients were randomly put into two groups. Some continued taking Xywav, and others were switched to a placebo. Researchers found that patients who were switched to placebo experienced worse sleep and more idiopathic hypersomnia symptoms than the patients who took Xywav.
How to Take Xywav
Xywav is a concentrated solution that must be diluted with water. The drug’s manufacturer advises patients to take the diluted drug once they are already in bed because it can take effect within five minutes and the onset of sleep can be sudden.
If two doses are used, they need to be taken between 2.5 and 4 hours apart. Patients should keep their second dose on their night table and might need to set an alarm to make sure that they wake up to take it on time.
Accessibility and Limitations of Xywav
Oxybate has the potential for physical or psychological dependence; therefore, it is a Schedule III controlled substance.
Patients who abruptly stopped taking Xyrem—another prescription version of oxybate—have reported withdrawal. Symptoms of withdrawal can include, insomnia, anxiety, psychosis, confusion, and more.
Xywav carries the potential for abuse. Since it causes central nervous system depression, the FDA is requiring that it be prescribed and dispensed through a Risk Evaluation and Mitigation Strategy program (REMS).
It can only be prescribed by certified healthcare professionals and dispensed only from certified pharmacies. Xywav will only be available by mail order from approved pharmacies and will not be available in retail pharmacies.
Known Side Effects
Common side effects reported by adults taking Xywav include:
NauseaHeadacheDizzinessAnxietyInsomniaDecreased appetiteExcessive sweatingVomitingDiarrheaDry mouthFatigueTremor
In the clinical trial for the drug:
21. 4% of patients reported nausea16. 2% reported headaches11. 7% reported dizziness10. 4% reported anxiety10. 4% reported vomiting
Xywav can also have more serious side effects like:
Breathing problems (including sleep apnea)Mental health side effects (including confusion, hallucinations, thoughts of suicide, anxiety, depression, and abnormal thinking)Sleepwalking (which can place a person at risk for injury)
Getting Xywav to Treat Your Idiopathic Hypersomnia
Oxybate can cause physical dependence. It is also a drug that can be abused, which means that there are special requirements for Xywav prescriptions.
If you think that you might have idiopathic hypersomnia, ask your doctor for a referral to a sleep specialist. They might ask you to keep a sleep diary and have an overnight test in a sleep laboratory.
Only certain doctors are allowed to prescribe Xywav. You will have to obtain the drug by mail order from certified pharmacies.
The out-of-pocket cost for Xywav is about $100,000 a year, according to a report by The New York Times. Most health insurance companies will cover Xywav, but you may have a high copayment. However, there are programs available to help with the cost of Xywav.
