The role of eszopiclone in the treatment of insomnia

Drug treatment of primary insomnia: a meta-analysis of polysomnographic randomized controlled trials

CONTEXT

Although insomnia is a frequent health complaint that is often treated with drugs, little is known about differences in treatment efficacy of various drug classes on objective versus subjective outcome measures.

OBJECTIVE

Our aim was to compare treatment efficacy of classical benzodiazepines, benzodiazepine receptor agonists (zopiclone, zolpidem and zaleplon), antidepressants (including low-dose doxepin), neuropeptides, progesterone receptor antagonists, hormones, melatonin receptor agonists, antihistamines, antiepileptics, and narcotics addressing primary insomnia.

DATA SOURCES

We conducted a comprehensive literature search (up to 5 April 2013) using PubMed, Cochrane Clinical Trials, PQDT OPEN, OpenGREY, ISI Web of Knowledge, PsycINFO, PSYNDEX, and the WHO International Clinical Trials Registry Platform.

ELIGIBILITY CRITERIA

Only polysomnographic, parallel-group, randomized controlled drug trials were included; eligibility was determined by two independent authors.

DATA SYNTHESIS

We used a random effects model, based on 31 studies reporting 80 treatment conditions, covering 3,820 participants.

RESULTS

Effect size estimates for the total sample of pooled drug classes suggest that there is a small-to-moderate, significant, and robust effect for objective outcomes (sleep onset latency g = -0.36, total sleep time g = 0.27) and subjective outcomes (sleep onset latency g = -0.24, total sleep time g = 0.21). Results indicate higher effect sizes for benzodiazepine receptor agonists and classical benzodiazepines compared with antidepressants (including low-dose doxepin) and for classical benzodiazepines compared with benzodiazepine receptor agonists. Benzodiazepine receptor agonists demonstrated higher effect sizes for objective outcomes.

LIMITATIONS

Data on drug safety were not analyzed.

CONCLUSIONS

Future studies should use objective and subjective assessment. Focusing on efficacy, clinicians should favor benzodiazepine receptor agonists and classical benzodiazepines over antidepressants (including low-dose doxepin) for primary insomnia treatment, but the additional consideration of different side effect profiles can lead to alternative treatment decisions.

Addressing sleep disturbances: an opportunity to prevent cardiometabolic disease?

There is increasing awareness of the role of sleep disturbance as an important factor in health and disease. Although sub-clinical sleep disturbances (insufficient sleep duration or inadequate sleep quality) may be difficult to assess with conceptual and/or methodological clarity, this review attempts to summarize and synthesize these findings. First, the concept of sleep disturbance in a public health context is introduced, to provide context and rationale. Second, operational definitions of 'cardiometabolic disease' and 'sleep disturbance' are offered, to address many unclear operationalizations. Third, the extant literature is summarized regarding short or long sleep duration and/or insufficient sleep, insomnia and insomnia symptoms, general (non-specific sleep disturbances), circadian rhythm abnormalities that result in sleep disturbances, and, briefly, sleep-disordered breathing. Fourth, the review highlights the social/behavioural context of sleep, including discussions of sleep and race/ethnicity, socio-economic position, and other social/environmental factors, in order to place these findings in a social-environmental context relevant to public health. Fifth, the review highlights the issue of sleep as a domain of health behaviour and addresses issues regarding development of healthy sleep interventions. Finally, a research agenda of future directions is proposed.

Melatonin and its analogs in insomnia and depression

Benzodiazepine sedative-hypnotic drugs are widely used for the treatment of insomnia. Nevertheless, their adverse effects, such as next-day hangover, dependence and impairment of memory, make them unsuitable for long-term treatment. Melatonin has been used for improving sleep in patients with insomnia mainly because it does not cause hangover or show any addictive potential. However, there is a lack of consistency on its therapeutic value (partly because of its short half-life and the small quantities of melatonin employed). Thus, attention has been focused either on the development of more potent melatonin analogs with prolonged effects or on the design of slow release melatonin preparations. The MT(1) and MT(2) melatonergic receptor ramelteon was effective in increasing total sleep time and sleep efficiency, as well as in reducing sleep latency, in insomnia patients. The melatonergic antidepressant agomelatine, displaying potent MT(1) and MT(2) melatonergic agonism and relatively weak serotonin 5HT(2C) receptor antagonism, was found effective in the treatment of depressed patients. However, long-term safety studies are lacking for both melatonin agonists, particularly considering the pharmacological activity of their metabolites. In view of the higher binding affinities, longest half-life and relative higher potencies of the different melatonin agonists, studies using 2 or 3mg/day of melatonin are probably unsuitable to give appropriate comparison of the effects of the natural compound. Hence, clinical trials employing melatonin doses in the range of 50-100mg/day are warranted before the relative merits of the melatonin analogs versus melatonin can be settled.

Melatonin agonists in primary insomnia and depression-associated insomnia: are they superior to sedative-hypnotics?

Current pharmacological treatment of insomnia involves the use of sedative-hypnotic benzodiazepine and non-benzodiazepine drugs. Although benzodiazepines improve sleep, their multiple adverse effects hamper their application. Adverse effects include impairment of memory and cognitive functions, next-day hangover and dependence. Non-benzodiazepines are effective for initiating sleep but are not as effective as benzodiazepines for improving sleep quality or efficiency. Furthermore, their prolonged use produces adverse effects similar to those observed with benzodiazepines. Inasmuch as insomnia may be associated with decreased nocturnal melatonin, administration of melatonin is a strategy that has been increasingly used for treating insomnia. Melatonin can be effective for improving sleep quality without the adverse effects associated with hypnotic-sedatives. Ramelteon, a synthetic analog of melatonin which has a longer half life and a stronger affinity for MT1 and MT2 melatonergic receptors, has been reportedly effective for initiating and improving sleep in both adult and elderly insomniacs without showing hangover, dependence, or cognitive impairment. Insomnia is also a major complaint among patients suffering from depressive disorders and is often aggravated by conventional antidepressants especially the specific serotonin reuptake inhibitors. The novel antidepressant agomelatine, a dual action agent with affinity for melatonin MT1 and MT2 receptors and 5-HT2c antagonistic properties, constitutes a new approach to the treatment of major depressive disorders. Agomelatine ameliorates the symptoms of depression and improves the quality and efficiency of sleep. Taken together, the evidence indicates that MT1/MT2 receptor agonists like ramelteon or agomelatine may be valuable pharmacological tools for insomnia and for depression-associated insomnia.