Dose-response effects of zaleplon as compared with triazolam (0.25 mg) and placebo in chronic primary insomnia

Comparative short-term safety and efficacy of hypnotics: A quantitative risk-benefit analysis

Several professional societies have provided recommendations for prescribing medications for insomnia. None has provided an integrative analysis that concurrently quantifies safety and efficacy (e.g., risk-benefit ratios). This represents an important gap for informing clinician decision-making. Accordingly, the aim of the present review is to provide such an analysis for five classes of sleep-promoting medications. Adverse event data values were extracted from the most recent FDA-approved package inserts and converted to an integer before being placebo-adjusted and standardized as a rate per 1000 (AEr). Efficacy data, pre-to-post self-reported data for active and placebo conditions were acquired from pivotal trials identified in "white papers" and systematic reviews/meta-analyses. Weighted effect sizes were calculated for subjective sleep latency, wake time after sleep onset and total sleep time, and then were averaged by medication class for each sleep continuity variable. Overall efficacy was represented by a single variable, SWT (sleep latency + wake time after sleep onset + total sleep time). Risk-benefit was represented using a simple ratio value. For safety, it was found that melatonin receptor agonists had the lowest adverse event rate (AEr = 43.1), and non-benzodiazepine benzodiazepine receptor agonists had the highest rate (AEr = 255.0). For efficacy, it was found that the pre-to-post placebo adjusted effect sizes were largest for benzodiazepines (effect size = 1.94) and smallest for melatonin receptor agonists (effect size = 0.109). For risk-benefit, histamine antagonist had the most favourable profile (risk-benefit = 69.5), while melatonin receptor agonist had the least favourable profile (risk-benefit = 395.7). Overall, the combined metric for risk-benefit suggests that treatment with a histamine antagonist is optimal and potentially represents the best first-line therapy for the medical management of insomnia.

The assessment and management of insomnia: an update

Insomnia poses significant challenges to public health. It is a common condition associated with marked impairment in function and quality of life, psychiatric and physical morbidity, and accidents. As such, it is important that effective treatment is provided in clinical practice. To this end, this paper reviews critical aspects of the assessment of insomnia and the available treatment options. These options include both non-medication treatments, most notably cognitive behavioral therapy for insomnia, and a variety of pharmacologic therapies such as benzodiazepines, "z-drugs", melatonin receptor agonists, selective histamine H1 antagonists, orexin antagonists, antidepressants, antipsychotics, anticonvulsants, and non-selective antihistamines. A review of the available research indicates that rigorous double-blind, randomized, controlled trials are lacking for some of the most commonly administered insomnia therapies. However, there are an array of interventions which have been demonstrated to have therapeutic effects in insomnia in trials with the above features, and whose risk/benefit profiles have been well characterized. These interventions can form the basis for systematic, evidence-based treatment of insomnia in clinical practice. We review this evidence base and highlight areas where more studies are needed, with the aim of providing a resource for improving the clinical management of the many patients with insomnia.

Investigation of the usefulness of zaleplon at two doses to induce afternoon-sleep under noise interference and its effects on psychomotor performance and vestibular function

BACKGROUND

Military operation personnel often suffer from sleep difficulty because of their work requirements. In this study, we investigated the efficacy of zaleplon at two doses to induce afternoon-sleep under noise interference and its effects on psychomotor performance and vestibular function; we subsequently established the optimal dosage regimen for military operation personnel.

METHODS

Twenty-two healthy young male volunteers were recruited for the study. Eight subjects took 10 mg or 15 mg of zaleplon and placebo alternately and then were exposed to noise. Changes in polysomnography (PSG) indices, including sleep latency (SL), sleep efficiency (SE) and sleep structure, were recorded after drug administration. After awakening, the volunteers' subjective judgments of sleep quality and sleepiness were measured. Eight volunteers underwent 3 psychomotor performance tests at a one-week interval, and the psychomotor performance tests were conducted before and after taking zaleplon and placebo. Six volunteers participated in the vestibular function test session, and parameters, including optokinetic nystagmus (OKN), vestibular ocular reflex (VOR), visual-vestibular ocular reflex (VVOR) and vestibular ocular reflex fixation suppression (VOR-Fix), were detected by the same experimental design as described above. The data of sleep observations were subjected to one-way variance analysis.

RESULTS

Compared with the placebo group, SL was shortened significantly, and the scores of subjective sleep quality and sleep depth were clearly increased in the zaleplon 10 mg group (P < 0.05). Moreover, the SE and the percent of REM (rapid eye movement) sleep were increased remarkably in the zaleplon 15 mg group (P < 0.01). Furthermore, the SE, percent of REM sleep and scores of subjective sleep depth in the zaleplon 15 mg group were significantly higher than in the zaleplon 10 mg group (P < 0.05). The psychomotor performance did not change significantly after ingestion of 10 mg or 15 mg of zaleplon, whereas the OKN and VOR gains were lower in the two dose groups of zaleplon (P < 0.05) and restored to normal 3 h after drug ingestion.

CONCLUSION

Zaleplon is an ideal hypnotic for military personnel, and its hypnotic efficiency is dose-related under noise interference; a 15 mg dose of zaleplon could provide significantly better sleep than a 10 mg dose of zaleplon.

Effect of sedative-hypnotics, anesthetics and analgesics on sleep architecture in obstructive sleep apnea

The perioperative care of obstructive sleep apnea (OSA) patients is currently receiving much attention due to an increased risk for complications. It is established that postoperative changes in sleep architecture occur and this may have pathophysiological implications for OSA patients. Upper airway muscle activity decreases during rapid eye movement sleep (REMS). Severe OSA patients exhibit exaggerated chemoreceptor-driven ventilation during non-rapid eye movement sleep (NREMS), which leads to central and obstructive apnea. This article critically reviewed the literature relevant to preoperative screening for OSA, prevalence of OSA in surgical populations and changes in postoperative sleep architecture relevant to OSA patients. In particular, we addressed three questions in regard to the effects of sedative-hypnotics, anesthetics and analgesics on sleep architecture, the underlying mechanisms and the relevance to OSA. Indeed, these classes of drugs alter sleep architecture, which likely significantly contributes to abnormal postoperative sleep architecture, exacerbation of OSA and postoperative complications.

Pharmacological treatment of sleep disturbance in developmental disabilities: a review of the literature

Sleep disturbance is a common problem in children with developmental disabilities. Effective pharmacologic interventions are needed to ameliorate sleep problems that persist when behavior therapy alone is insufficient. The aim of the present study was to provide an overview of the quantity and quality of pharmacologic research targeting sleep in children with developmental disabilities. Efficacy studies of medications most likely to be prescribed to children are reviewed in detail. Medline and PsychInfo searches were performed to identify relevant clinical trials and case reports, published between 1975 and 2009. Key search terms included sleep, children, antihistamines, alpha adrenergic agonists, antidepressants, antipsychotics, melatonin, ramelteon, benzodiazepines, and nonbenzodiazepines. The literature search identified 58 articles that met the inclusion criteria. Well-controlled studies employing both objective polysomnography and subjective sleep measures are needed to determine the efficacy and safety of currently prescribed pediatric sleep medicines. Melatonin appears to be the most widely assessed agent and safest choice for children with developmental disabilities. Trazodone, mirtazapine, and ramelteon hold promise but require further study.

Clinical evaluation of zaleplon in the treatment of insomnia

Zaleplon is a pyrazolopyrimidine hypnotic used for the treatment of insomnia. Zaleplon binds preferentially at the α1β2γ2 subunit of gamma aminobutyric acid type A (GABAA) receptors in the central nervous system, and has a half-life of about one hour. Efficacy studies show that zaleplon is a suitable hypnotic for sleep initiation purposes. However, because of its short half-life, zaleplon is less effective in sleep maintenance when compared with other hypnotics. Nevertheless, zaleplon does increase total sleep time. No rebound effects are observed after treatment discontinuation. The use of zaleplon is relatively safe. Adverse effects are mild and of short duration. No important interactions have been reported, and there is no evidence of abuse potential. Relative to benzodiazepine hypnotics, the biggest advantage of zaleplon is that current evidence suggests it does not produce residual next-day effects. As early as four hours after intake of zaleplon, no effects on cognitive, memory, psychomotor performance, and the ability to drive a car have been reported. Future studies should confirm these findings, and comparisons with new nonbenzodiazepine hypnotics should determine the importance of zaleplon in the future treatment of insomnia.

A compendium of placebo-controlled trials of the risks/benefits of pharmacological treatments for insomnia: the empirical basis for U.S. clinical practice

For many years practitioners have had limited data from double-blind, placebo-controlled studies to guide the types of decision-making needed to optimally manage patients with insomnia in clinical practice. However, in recent years there has been a great increase in insomnia research studies that address issues of clinical importance. This body of work represents an increasingly useful empirical basis for making clinical practice decisions. The purpose of this article is to compile the body of work on the pharmacological management of insomnia to make it available in as accessible form as possible for optimal application in clinical practice with the hopes that doing so will decrease the gap separating the available research and the clinical management of insomnia and, thereby, improve the care of the many individuals who suffer from this condition. The review of studies consists of the following sections: 1) basic pharmacology; 2) double-blind, placebo-controlled trials in adults with primary insomnia; 3) double-blind, placebo-controlled trials in elderly patients with primary insomnia; 4) adverse effects reported in placebo-controlled trials in elderly primary insomnia patients; 5) double-blind, placebo-controlled trials in adults and the elderly as a function of treatment duration; 6) double-blind, placebo-controlled trials of the treatment of comorbid insomnia. Issues related to the application of these data to clinical practice are discussed in the text.

Pharmacology of ramelteon, a selective MT1/MT2 receptor agonist: a novel therapeutic drug for sleep disorders

An estimated one-third of the general population is affected by insomnia, and this number is increasing due to more stressful working conditions and the progressive aging of society. However, current treatment of insomnia with hypnotics, gamma-aminobutyric acid A (GABA(A)) receptor modulators, induces various side effects, including cognitive impairment, motor disturbance, dependence, tolerance, hangover, and rebound insomnia. Ramelteon (Rozerem; Takeda Pharmaceutical Company Limited, Osaka, Japan) is an orally active, highly selective melatonin MT(1)/MT(2) receptor agonist. Unlike the sedative hypnotics that target GABA(A) receptor complexes, ramelteon is a chronohypnotic that acts on the melatonin MT(1) and MT(2) receptors, which are primarily located in the suprachiasmatic nucleus, the body's "master clock." As such, ramelteon possesses the first new therapeutic mechanism of action for a prescription insomnia medication in over three decades. Ramelteon has demonstrated sleep-promoting effects in clinical trials, and coupled with its favorable safety profile and lack of abuse potential or dependence, this chronohypnotic provides an important treatment option for insomnia.

Therapeutic Options for Sleep-Maintenance and Sleep-Onset Insomnia

Insomnia, defined as difficulty falling asleep, staying asleep, and/or experiencing restorative sleep with associated impairment or significant distress, is a common condition resulting in significant clinical and economic consequences. Many options are available to treat insomnia, to assist with either falling asleep (sleep onset) or maintaining sleep. We searched MEDLINE for articles published between January 1996 and January 2006, evaluated abstracts from recent professional meetings, and contacted the manufacturer of the most recent addition to the pharmacologic armamentarium for insomnia treatment (ramelteon) to gather information. Nonpharmacologic options include stimulus control, sleep hygiene education, sleep restriction, paradoxical intention, relaxation therapy, biofeedback, and cognitive behavioral therapy. Prescription and over-the-counter drug therapies include benzodiazepine and nonbenzodiazepine sedative-hypnotic agents; ramelteon, a melatonin receptor agonist; trazodone; and sedating antihistamines. Herbal and alternative preparations include melatonin and valerian. Before recommending any treatment, clinicians should consider patient-specific criteria such as age, medical history, and other drug use, as well as the underlying cause of the sleep disturbance. All pharmacotherapy should be used with appropriate caution, at minimum effective doses, and for minimum duration of time.

Sleep maintenance insomnia: strengths and weaknesses of current pharmacologic therapies

BACKGROUND

Although insomnia is highly prevalent, sleep disturbances often go unrecognized and untreated. When insomnia is recognized, considerable emphasis has been placed on improving sleep onset; however, there is growing evidence that improving sleep maintenance is an equally important treatment goal.

METHODS

A MEDLINE literature search was performed using the search parameters "insomnia," "zolpidem," "zaleplon," "flurazepam," "estazolam," "quazepam," "triazolam," and "temazepam," as these agents are FDA-approved for the treatment of insomnia. Per reviewer comments, the search criteria was later expanded to include lorazepam. A literature search using the terms "trazodone" and "insomnia" was also performed, as this is the second-most commonly prescribed agent for treating insomnia. Sleep efficacy endpoints from randomized, placebo-controlled clinical trials in adult populations and key review articles published between 1975 and 2004 were included in this review. As only one randomized placebo-controlled trial evaluated trazodone use in primary insomnia, the trazodone search was expanded to include all clinical trials that evaluated trazodone use in insomnia. Relevant texts and other articles that evaluated side effect profiles of these agents were also included, one of which was published in January of 2005. In all publications, impact of treatment on sleep maintenance parameters (wake time after sleep onset, number of awakenings) and measures of next-day functioning were evaluated, in addition to sleep onset parameters (sleep latency, time to sleep onset/induction) and sleep duration data (total sleep time).

RESULTS

Many of the currently available agents used to treat insomnia, including the antidepressant trazodone, the non-benzodiazepine hypnotics zolpidem and zaleplon, and some of the benzodiazepines, have not consistently demonstrated effectiveness in promoting sleep maintenance. Furthermore, the benzodiazepines with established sleep maintenance efficacy are associated with next-day sedation, the risk of tolerance and dependence, or both.

CONCLUSIONS

New agents that offer relief of sleep maintenance insomnia without residual next day impairment while improving next day function are needed. Several compounds currently under development may offer clinicians a more effective and safer treatment for this common disorder.

Benefit-risk assessment of zaleplon in the treatment of insomnia

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.

Correlates and consequences of chronic insomnia

Approximately one half of patients with insomnia have a primary psychiatric disorder such as a depression or anxiety. Insomnia is associated with increased risk of new or recurrent psychiatric disorders, increased daytime sleepiness with consequent cognitive impairment, poorer prognoses, reduced quality of life and high healthcare-related financial burden. Emerging data suggest that resolution of insomnia may improve psychiatric outcomes, which underscores the importance of vigorous treatment. Unfortunately, only a small percentage of patients receive such care. An ideal monotherapeutic strategy would treat both depression and insomnia. There are, however, only a handful of modern antidepressants that objectively improve sleep maintenance problems, and none do so without causing adverse next-day effects such as sedation. Thus, a significant number of patients must take adjunctive hypnotic medications, even though longer-term efficacy has not been established. New and emerging anti-insomnia agents may prove useful in the long-term treatment of chronic insomnia. Further research is needed to establish the benefits of such treatment.

Pharmacodynamic profile of Zaleplon, a new non-benzodiazepine hypnotic agent

The challenge in developing hypnotic agents for the treatment of insomnia is to balance the sedative effect needed at bedtime with the residual sedation on awakening. Zaleplon is a novel pyrazolopyrimidine hypnotic agent that acts as a selective agonist to the brain omega(1) receptor situated on the alpha(1) subunit of the GABA(A) receptor complex. Zaleplon was proven to be an effective hypnotic drug as it consistently and significantly reduced latency to persistent sleep in insomniac patients for doses of 10 mg and above in polysomnography studies. The pharmacodynamic profile of zaleplon on psychomotor performance, actual driving and cognitive function, including memory, was assessed in several randomized, double-blind, placebo-controlled studies in healthy young subjects as well as insomniac patients by using various positive controls (zolpidem, zopiclone, triazolam and flurazepam). The recommended hypnotic dose of zaleplon in young adults (10 mg) produced minimal or no impairment of psychomotor and memory performance even when administered during the night as little as 1 h before waking. No impairment of actual driving was observed when zaleplon 10 mg was administered either at bedtime or in the middle of the night as little as 4 h before waking. Zaleplon 20 mg, twice the recommended dose, generally produced significant impairment of performance and cognitive functions when these functions were measured at the time of peak plasma concentration, i.e. 1 h after dose administration, and no impairment of driving abilities was observed 4 h after a middle-of-the-night administration. In contrast, consistent detrimental residual effects on various aspects of psychomotor and cognitive functions were observed with the therapeutic doses of the various commonly prescribed hypnotic agents used as comparators, e.g. zolpidem 10 mg up to 5 h after dose administration, zopiclone 7.5 mg up to 10 h after, flurazepam 30 mg up to 14 h after and triazolam 0.25 mg up to 6 h after. Also, zolpidem 10 mg and zopiclone 7.5 mg were also shown to significantly impair driving ability the next morning when this was measured 4 h and up to 10 h after dose administration, respectively. The present review shows that zaleplon 10 mg has little or no residual effect when administered in the middle of the night, as late as 1 h before waking, and is devoid of impairment of driving abilities as assessed by actual driving 4 h after dose administration. The lack of clinically significant or minimally statistically significant residual effects of zaleplon even at its peak concentration may be explained by its unique pharmacokinetic (rapid elimination half-life) and pharmacodynamic (low affinity, and specific binding profile to various subunits of the GABA(A)receptor) profiles. These properties allow zaleplon to be used for treatment of symptoms only when they occur, either at bedtime or later in the night, without incurring significant risk of developing next-day impairment of psychomotor and cognitive functioning. Copyright 2001 John Wiley & Sons, Ltd.