New Sleeping Pills Are Effective, but None Stands Out as the Best
The spate of new sleeping pills on the market are effective treatments for insomnia, but they have different effects and no one drug stands out as the best, according to a new review of studies on drugs including Sonata, Ambien and Lunesta.
Reviewers from the Oregon Evidence-based Practice Center at the Oregon Health and Science University concluded that the drugs were better than placebo pills at treating insomnia symptoms such as trouble falling asleep and staying asleep.
There were few head-to-head comparisons of the drugs, however, and "although there are some differences between the drugs on some outcomes, no one drug appeared to be consistently superior," say the Oregon reviewers, led by Susan Carson, M.P.H.
The Oregon Evidence-based Practice Center makes available information regarding the comparative effectiveness and safety profiles of different drugs within pharmaceutical classes.
The review included 141 studies of Sonata, Ambien, Lunesta and Imovane, a Canadian brand. The medicines are considered newer sleep aids and have been on the market since 1992. The drugs are commonly prescribed for insomnia in place of older sedatives such as benzodiazepines (marketed under brands such as Halcion, ProSom and Restoril).
Benzodiazepines work through the same brain receptors as the newer drugs and are also effective sleep aids, but researchers believe that the newer drugs are less likely to lose their effectiveness or lead to abuse over time.
In the seven head-to-head studies of the newer drugs identified by Carson and colleagues, the researchers uncovered some differences. In the four studies comparing Sonata to Ambien, for example, Sonata was better than Ambien at putting people to sleep quickly, while patients on Ambien slept longer and reported having a better quality sleep than those taking Sonata.
"Although there are some differences among the drugs on the different outcomes, it does not follow that one drug would necessarily be more or less effective for patients with one type of insomnia over another," Carson said. "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."
Short-term side effects such as headaches and daytime sleepiness occurred at similar rates with the drugs, the reviewers found.
The reviewers found few studies that looked specifically at the drugs' performance in groups such as older adults and pregnant women or that compared effects between racial groups or men and women.
One study of older women found that those taking Ambien were more likely to suffer hip fractures than those taking no sleep aids, but Carson cautioned that the study could not tell whether other factors may have led to broken hips.
"Additionally, no studies like this have been conducted with the other drugs, so we can't say if the other newer sedative hypnotics would have a similar effect or not," she said.
The Oregon reviewers also compared the newer drugs to benzodiazepines. Most of these comparisons found that the newer drugs were as effective as benzodiazepines, with similar side effects.
Carson and colleagues say there are no comparative studies that track the long-term effectiveness and safety of the new sleep aids, although there have been some reports of patients becoming dependent on Ambien and Imovane.
Studies that look at long-term serious events such as bone fractures, abuse and withdrawal symptoms are needed, Carson says, noting that the longest placebo-controlled study of these drugs is only six months long.
"Most of these drugs are not approved for longer-term use, because the studies have not been conducted, but in practice patients may take them for a longer period than the recommended seven to 10 days. So studies that mirror the ways the drugs are actually used would be very helpful," Carson said.
The National Institutes of Health estimates that more than 70 million Americans have trouble sleeping, with the likelihood of insomnia increasing with age.
An October 2005 study conducted by Medco Health Solutions, a managed care company, found that Americans ages 65 and older are still the largest users of prescription sleeping pills. Sleeping pill use among adults 20 to 44 years old has doubled in the past four years, spending on them has increased by 190 percent and drug companies spent $2.1 billion advertising them in 2004. The number of sleep aid prescriptions for children and younger adults ages 10 to 19 jumped 85 percent between 2000 and 2004, the Medco researchers found.