May 5, 2006

Kennedy Case puts Ambien again under Spotlight

By Kim Dixon

CHICAGO (Reuters) - U.S. Rep. Patrick Kennedy's statement that he used Sanofi-Aventis's sleep drug Ambien, to explain how he might have been involved in a late-night car crash, has led to renewed attention on the drug's possible side-effects.

The Rhode Island Democrat had also taken the prescription nausea drug phenergan before crashing his car into a security barrier in Washington D.C. early Thursday morning. Nobody was hurt but the incident has intensified questioning about whether the drug causes side-effects like sleepwalking and binge eating, and how prevalent they are.

"There is white hot attention on this particular agent, but we need to be cautious about jumping to conclusions," said Michael Sateia, chief of sleep medicine at Dartmouth Medical School. "We have no systematic data yet."

Sanofi-Aventis says Ambien, used by millions of people since its introduction in 1993, has lulled patients to sleep for 12 billion nights. It says sleepwalking is a rare side effect and it stands by the drug's safety.

But researchers at Hennepin County Medical Center in Minnesota have identified more than two dozen cases of dangerous sleepwalking among people who took Ambien, and they believe the phenomenon is more common than the company says.

"We are seeing pretty extreme expressions of sleepwalking - like getting into a car and driving," said Michel Cramer-Bornemann, a researcher at the clinic. "And when we remove the Ambien, it is resolved."

The data, to be submitted for publication in several months, is still anecdotal. "But good science starts with observation," he said.

About 30 million people in the United States take sleep medications, according to the American Academy of Sleep Medicine and Ambien leads the market by far. By some counts, that is a 50 percent jump in the use of such drugs since the beginning of the decade.

Serious alleged side-effects are short-term memory loss and cases of patients involved in road accidents a day after taking the drug who complained they still felt drugged.

Sanofi has said about 4 percent of people might sleep walk with or without the drug.

That estimate is a bit high, according to Donna Arand, president of the American Insomnia Association.

She explained that sleepwalking occurs when a patient's brain goes into the deepest cycles of sleep and has trouble getting back into the lighter cycles. "You end up with a sleeping brain and an awake body," she said.

Sateia of Dartmouth suggested that Sanofi reexamine the original trial data it submitted to regulators when it won approval.