Stanford Report, October 18, 2006

Study tests potential new sleeping pill

BY EWEN CALLAWAY

Could a drug that treats narcolepsy help people with insomnia? Researchers at the School of Medicine's Sleep Disorders Center will study that question.

The drug, sodium oxybate, is used to treat some symptoms of narcolepsy, a neurological disorder marked by a sudden, uncontrollable urge to sleep. "When we give this agent in narcolepsy, we have an impact on sleep. But also, daytime function is significantly improved and the capacity to remain alert is improved," said Jed Black, MD, assistant professor of psychiatry and behavioral sciences. Because of those effects, he explained, it may also help people who have trouble sleeping.

Black is the lead investigator of an 18-month pilot study to determine whether sodium oxybate can help patients who have trouble sleeping. The study will compare the sleeping pill zoldipem tartrate, marketed as Ambien, with the narcolepsy drug sodium oxybate, marketed as Xyrem.

The study is funded by the manufacturer of sodium oxybate, Jazz Pharmaceuticals, which is based in Palo Alto. Black, the study leader, has conducted other studies funded by Jazz.

Black and his colleagues are interested in sodium oxybate because it works differently than zoldipem tartrate and other popular prescription sleep medications. While both drugs affect a brain chemical, called GABA, that is important to sleep, these drugs act on GABA in different ways.

Sodium oxybate, also known as gamma hydroxybutyrate or GHB, received approval from the U.S. Food and Drug Administration in 2002 to treat a small population of patients with narcolepsy who experience episodes of cataplexy, a condition characterized by weak or paralyzed muscles.

Patients enrolled in the new study will be randomly assigned to take zoldipem tartrate, sodium oxybate or a placebo for 13 weeks. During this time, researchers at the sleep center will track progress through patient sleep logs, overnight observation at the sleep center and daytime testing.

Overnight visits will "tell us when a person is asleep and what stage of sleep they're in," said Black.

There will also be daytime tests of memory, problem solving and reaction time, which will allow the researchers to determine whether the drugs are helping patients during the day.

Volunteers between the ages of 18 and 75 who regularly have trouble sleeping are needed for the study. Researchers aim to enroll 60 participants over the next year.

Participants will receive $100 for each of four overnight visits and an additional $150 for completing the study. Prospective volunteers can get more information from clinical coordinator Paul Stowers at 725-8910 or pstowers@stanford.edu.

Ewen Callaway is a science-writing intern in the Office of Communication & Public Affairs at the School of Medicine.