F.D.A. Approves GHB, a ‘Date Rape’ Drug, for Rare Sleeping Disorder

On the black market, homemade GHB — also known as liquid ecstasy, goop and G — can be bought by the capful for $5 to $25. But nightly treatments of Xyrem and Xywav cost roughly $100,000 a year. The new approval will make it much easier for hypersomnia patients to get insurance coverage for Xywav.

Many doctors and patients have never heard of idiopathic hypersomnia, Mr. Cozadd said, but Jazz will aim to change that. “There’s an educational effort that we’ll be part of,” he said, “which is really making sure there’s a better understanding among treaters and among patients of the condition and its treatment.”

The F.D.A. said its decision was significant because it is the first drug approved to treat the disorder.

“Idiopathic hypersomnia is a lifelong 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,” said Dr. Eric Bastings, deputy director of the agency’s Office of Neuroscience, in a statement.

In March, Jazz and the Hypersomnia Foundation, a patient advocacy group, began an awareness campaign — “I have IH” — which included an online survey of health care providers’ knowledge of the condition (it was low), and advertisements in Times Square.

“I never thought I’d live to see that day — it was very emotional,” said Betsy Ashcraft, the treasurer of the foundation’s board of directors, whose adult son has idiopathic hypersomnia. (Jazz paid the foundation for board members’ time consulting on the campaign, she said.)

GHB is an old drug, first synthesized by a Russian chemist in 1874. A century later, it was sold as a dietary supplement in the United States, and academic researchers began reporting that it greatly improved the nighttime sleep of people with narcolepsy and curbed their daytime attacks of paralysis, called cataplexy.