Dec. 9, 2005 - Those heavily advertised prescription sleep drugs do work, but no single drug stands out as clearly superior to the others, a new review of the research shows.
But there was little evidence that any one drug worked better than another for specific types of insomnia because only a few trials compared the medications head to head. Not much information was available about the safety of long-term use.
"We found no studies comparing the different drugs in patients with different insomnia complaints, so we do not know for sure that one drug would work better in one patient over another," says researcher Susan Carson, MPH. Carson is a senior research associate at the Oregon Evidence-Based Practice Center.
Sleep experts who spoke to WebMD said that even though the clinical trials have not established clear differences between the drugs, clinical practice has.
Ambien and Sonata are more shorter acting than Lunesta or a newly available, extended release form of Ambien, known as Ambien CR, says Edward J. Stepanski, PhD.
Shorter-Acting vs. Longer-Acting Drugs
The shorter-acting drugs may be the best choice for people who have trouble falling asleep but have no trouble staying asleep, he says.
Stepanski directs the Sleep Disorders Service and Research Center at Chicago's Rush University Medical Center. He is also president of the American Sleep Medicine Foundation.
He says the longer-acting drugs tend to work better for people who wake frequently during the night and can't get back to sleep.
The new-generation sleep aides more directly target the area of the brain that controls sleep than earlier drugs. As a result they are less addictive and less likely to cause daytime grogginess.
But the Oregon researchers say the long-term safety and side effects of the drugs have never been compared. They note that there is evidence that patients can become addicted to them.
David Neubauer, MD, says clinical experience over more than a decade has proven that the risk of abuse and addiction is small.
Neubauer is associate director of the Johns Hopkins Sleep Disorders Center. He is also author of the book Understanding Sleeplessness: Perspectives on Insomnia.
"For the most part the people who misuse these medications are the ones who misuse other things as well," he says.
Carson tells WebMD that comparative studies and studies that track the long-term effectiveness and safety of the drugs are still needed. Although most of the drugs are not approved for long-term use, many patients take them for extended periods.
She adds that there is at least some evidence that the drugs can increase the risk of bone fractures in elderly people who take them. Older people tend to have the most sleep problems and are the most frequent users of prescription sleeping pills.
"We need longer-term, controlled studies to look at adverse events," she says.