FDA approves a generic of Xyrem to treat Cataplexy and excessive daytime sleepiness

The U.S. Food and Drug Administration (FDA) has approved the first generic version of Xyrem (sodium oxybate) Oral Solution, to treat cataplexy and excessive daytime sleepiness in patients with narcolepsy, which is a potentially debilitating disease. Cataplexy is a primary symptom of narcolepsy where patients suddenly lose muscle tone, including voluntary muscle control, while awake. Muscle weakness or paralysis associated with cataplexy may cause a person to collapse. Approximately 70 percent of people with narcolepsy have cataplexy. Sodium oxybate is the only medication approved to treat cataplexy in patients with narcolepsy.

The use of Xyrem has been associated with serious side effects including seizures, trouble breathing, changes in alertness, coma, and death. Additionally, the active ingredient in Xyrem (and in the newly approved generic) is sodium oxybate. Sodium oxybate is the sodium salt of gamma hydroxybutyrate (GHB). GHB has not been approved for any medical use and has the potential for abuse, such as in cases of sexual assault.

Because of the potential risks associated with Xyrem, it is subject to strict safety controls on prescribing and dispensing under a program called a Risk Evaluation and Mitigation Strategy (REMS). FDA’s approval of generic sodium oxybate is subject to a REMS with strict safety controls that are comparable to those currently required for Xyrem.

Specifically, under both the Xyrem REMS and the generic sodium oxybate REMS, sodium oxybate can be prescribed only by a certified prescriber, and dispensed only to an enrolled patient by a certified pharmacy. Only a certified pharmacy that ships directly to patients can dispense sodium oxybate. Sodium oxybate will not be available in retail pharmacies.

In approving this generic version of Xyrem, the FDA is maintaining strict safety requirements for sodium oxybate, while providing patients with access to a generic medication option for narcolepsy.

According to the National Institutes of Health, narcolepsy is a chronic brain disorder that involves poor control of sleep-wake cycles. People with narcolepsy experience periods of extreme daytime sleepiness and sudden, irresistible bouts of sleep that can strike at any time. These “sleep attacks” usually last a few seconds to several minutes.

Narcolepsy can greatly affect daily activities. People may unwillingly fall asleep while at work or at school, when having a conversation, playing a game, eating a meal, or, most dangerously, when driving or operating other types of machinery.

Another primary symptom of narcolepsy is cataplexy, which involves a sudden loss of muscle tone, including voluntary muscle control, while awake; this sudden loss of muscle control can result in falls and resulting injuries. Nearly half of patients with narcolepsy report that their sleepiness and cataplexy substantially interfere with their daily lives, including school, jobs, marriages, or social life. Sodium oxybate markedly reduces cataplexy and is also effective in treating excessive daytime sleepiness in narcolepsy; therefore, it can help prevent falls and injuries, falling asleep at the wheel, and other serious problems caused by narcolepsy. Sodium oxybate is an important therapy for narcolepsy.