Insomnia is a heterogeneous, highly prevalent condition that is associated with a high level of psychiatric, physical, social and economic morbidity. The treatment of
insomnia involves pharmacological and non-pharmacological interventions. The mainstay of pharmacological treatment of
insomnia has been the
benzodiazepines, the introduction of which represented a significant improvement over the
barbiturates and
chloral hydrate. Although
benzodiazepines have been shown to be efficacious in treating
insomnia, they have also been associated with a number of adverse effects including tolerance, dependence, withdrawal and abuse potential, impairment in daytime cognitive and psychomotor performance (including an increased risk of accidents and falls), adverse effects on respiration and the disruption of normal sleep architecture with reduction in both slow wave sleep and rapid eye movement. In the last decade, the treatment of
insomnia has been supplemented by the introduction of a number of non-
benzodiazepine hypnotics including
zolpidem,
zopiclone and, most recently,
zaleplon.
Zaleplon possesses a unique pharmacological profile, with an ultra-short half-life of about 1 hour, and selective binding to the BZ1(omega1) receptor subtypes of the
GABA(A) receptor. This unique pharmacological profile predicts a number of pharmacodynamic properties that account for a unique benefit-risk profile. Consistent with these predictions,
zaleplon has been shown in a number of studies to be efficacious in promoting sleep initiation, but less so in promoting sleep maintenance. The adverse effects associated with
zaleplon have been shown to be more rapidly resolved and/or lesser in magnitude than those associated with
benzodiazepines (including
triazolam) and the longer acting non-
benzodiazepine hypnotics (
zolpidem and
zopiclone). This improved risk profile includes: the effects of
zaleplon on psychomotor and cognitive performance; tolerance, withdrawal and rebound;
respiratory depression; sleep architecture; and other treatment-emergent adverse effects. The unique benefit-risk profile of this agent may be particularly suitable for certain patients with
insomnia and provides yet another option in the management of this impairing condition.