NIH consensus panel reviews treatments for insomnia.(Clinical Rounds)

New benzodiazepine receptor agonists for chronic insomnia--zaleplon, zolpidem, and eszopiclone--have shown fewer adverse effects compared with other medications, but additional studies are needed to assess these drugs' long-term effectiveness, concluded members of an independent panel convened by the National Institutes of Health in Bethesda, Md.

Only eszopiclone (Lunesta) has been approved for the long-term treatment of insomnia; the other drugs are approved for up to 35 days of use.

Five benzodiazepines--estazolam, flurazepam, quazepam, temazepam, and triazolam--also are approved by the Food and Drug Administration to treat insomnia, but adverse events including dependence, daytime sleepiness, and lack of motor coordination are more likely with these drugs than with the new receptor agonists.

Although commonly used, these medications require more research. "There are very few data on their efficacy in the treatment of chronic insomnia, yet we know from other research that they produce substantial side effects," panelist Robert J. DeRubeis, Ph.D., said in an interview.

After reviewing information on the latest research and the available treatments, the panel members concluded that limited guidance and resources exist for clinicians about the treatment of chronic insomnia. They emphasized that more research is needed on the available treatment methods, which include hypnotic medications, behavioral therapy, and alternative medicine, as well as antidepressants, antihistamines, and antipsychotics.

Given the availability of treatments with demonstrated efficacy and fewer side effects in the short term, the panel could not recommend off-label use of nonapproved substances, said Dr. DeRubeis, chair of the department of psychology at the University of Pennsylvania in Philadelphia.

Antidepressants, particularly trazodone, are often prescribed off label for insomnia, but there are no data on the effects of long-term use of such agents, the panelists noted.