Use of non-benzodiazepine hypnotics in the elderly: are all agents the same?

Sleep disorders, especially insomnia, are common in older adults. These disorders are frequently treated using non-benzodiazepine hypnotics. Nonetheless, there is a relative lack of data regarding the use of these agents in the elderly, and whether any of these medications is superior to any other in the class when used in the elderly is also unclear. In this article, we review, by way of the published literature, the pharmacodynamics, pharmacokinetics, drug interactions, efficacy and safety of zolpidem, zaleplon, zopiclone, eszopiclone and ramelteon in the elderly. Special emphasis is placed on identifying relevant differences between these medications when used in older adults with insomnia. Based primarily on data from placebo-controlled trials, the non-benzodiazepines reviewed were found to be most effective at improving sleep latency and sleep quality, and least effective at enhancing total sleep time. The efficacy of ramelteon was limited to improving sleep latency, while all other agents, especially at higher doses, were found to produce improvement in both sleep latency and some improvement in total sleep time. All of the medications were found to be well tolerated in the elderly. From pharmacokinetic and drug-drug interaction perspectives, zaleplon and ramelteon offer the advantage of not being primarily metabolised via the cytochrome P450 3A4 isoenzyme. In conclusion, based on relatively limited data, zopiclone, zolpidem, zaleplon, eszopiclone and ramelteon represent modestly effective and generally well tolerated treatments for insomnia in older adults. While some actual and potential differences exist among these medications, more comparative trials are needed.