New drugs for insomnia: comparative tolerability of zopiclone, zolpidem and zaleplon

Zolpidem: a review of its use in the management of insomnia

Zolpidem (Ambien, Stilnox, Myslee, an imidazopyridine, is a nonbenzodiazepine hypnotic indicated for the short-term treatment of insomnia. Zolpidem improves sleep in patients with insomnia. Its overall tolerability is favourable when administered according to the manufacturer's prescribing information, with a low propensity to cause clinical residual effects, withdrawal, dependence or tolerance. In addition, most evidence suggests that the drug is associated with minimal rebound insomnia. In the only clinical trials that investigated the use of a hypnosedative drug in an 'as-needed' regimen, zolpidem produced a global improvement in sleep. Thus, zolpidem continues to be a useful therapeutic option in the pharmacological treatment of patients with insomnia.

Effects of ramelteon (TAK-375) on nocturnal sleep in freely moving monkeys

We investigated the effects of (S)-N-[2-(1,6,7,8-tetrahydro-2H-indeno-[5,4]furan-8-yl)ethyl]propionamide (ramelteon, TAK-375), a novel MT1/MT2 receptor agonist, on nocturnal sleep in freely moving monkeys and compared these results with those of melatonin and zolpidem. Treatment with ramelteon (0.03 and 0.3 mg/kg, p.o.) significantly shortened latency to sleep onset and significantly increased total duration of sleep. Treatment with melatonin (0.3, 1, and 3 mg/kg, p.o.) also decreased sleep latency, but the effect was weak; the only significant reduction was seen with the 0.3 mg/kg dose on latency to light sleep. Melatonin had no significant effects on the duration of sleep. Zolpidem had no significant effects on latency to sleep onset in this study at any dose (1, 3, 10, and 30 mg/kg, p.o.). The highest dose (30 mg/kg) of zolpidem had a tendency to increase slow wave sleep; however, it also induced apparent sedation and myorelaxation. Treatment with ramelteon and melatonin had no evident effect on the general behavior of the monkeys. Spectral analysis (fast Fourier transform, FFT) of both ramelteon and melatonin revealed sleep patterns that were indistinguishable from those of naturally occurring sleep. The EEG power spectra of zolpidem were qualitatively different from that of naturally occurring physiological sleep. Results of the present study support the investigation of ramelteon as a sleep-promoting agent in humans.

Current patterns and future directions in the treatment of insomnia

BACKGROUND

Despite the high prevalence and the high burden associated with chronic insomnia, it remains largely unrecognized and often inadequately treated by physicians.

METHODS

A review was undertaken of the literature on barriers to both acute and chronic treatment of insomnia, as well as recent trials of pharmacologic and nonpharmacologic agents for insomnia.

RESULTS

Obstacles to appropriate treatment of the condition include outdated insomnia management guidelines, which have contributed to US Food and Drug Administration restrictions on longer-term prescription of hypnotic agents; lack of research demonstrating the benefit of treating insomnia; and fears of tolerance and withdrawal effects of long-term use of hypnotic agents, as well as an absence of longer-term, randomized, controlled, double-blind trials of existing agents used to treat insomnia.

CONCLUSIONS

There is evidence that improved sleep may improve outcome in some medical and psychiatric illnesses. Both behavioral and pharmacologic therapies have shown efficacy in chronic insomnia. In addition, a recent 6-month, randomized, controlled study has demonstrated that at least one agent may be safe and effective in longer-term use.

Psychomotor performance in healthy young adult volunteers peceiving lormetazepam and placebo: A single-dose, randomized, double-blind, crossover trial

BACKGROUND

Lormetazepam is a hypnotic benzodiazepine currently used in the treatment of insomnia. When this agent is used appropriately, its pharmacologic properties predict a high therapeutic index with a good tolerability profile.

OBJECTIVE

The primary aim of this study was to compare the effects on psychomotor performance of lormetazepam and placebo in healthy young adult subjects. A secondary objective was to evaluate the clinical tolerability of lormetazepam.

METHODS

This was a randomized, double-blind,placebo-controlled, crossover study in healthy young adult volunteers. All volunteers received single doses of lormetazepam 1 mg and placebo, with a 1-week interval between doses. The primary study variables were visual simple reaction time (VSRT) and visual choice reaction time (VCRT), measured before dosing with lormetazepam or placebo and at 20, 60, 120, 180, 240, and 360 minutes after dosing using a standard computerized apparatus. To increase the sensitivity of the results, visual reaction times were also recorded using a validated mobile computerized device. Secondary variables were the duration and quality of sleep on the night before each study session, rated by subjects using a 100-mm visual analog scale; the Epworth Sleepiness Scale for daytime drowsiness; and the Critical Flicker Fusion Threshold test. Spontaneously reported adverse events were recorded and monitored throughout the study.

RESULTS

The study included 18 healthy young adult volunteers (12 women, 6 men; mean [SD] age, 26.7 [2.8] years [range, 21-30 years]; mean body weight, 58 [9.5] kg). There were no significant differences in either VSRT or VCRT after administration of lormetazepam or placebo. Independent of study drug but consistent with the accepted range of variability between the 2 devices, overall reaction times were significantly shorter with the use of the mobile device compared with the standard apparatus (P < 0.01). Analysis of the results showed no sequence effects or other evidence of learning. There were no changes in the secondary study variables after administration of the test drugs. Administration of lormetazepam was associated with dizziness in 2 subjects, in 1 case occurring in association with somnolence. These adverse events were mild and subsided spontaneously 3 hours after drug intake. After administration of placebo, 1 subject reported slight somnolence 60 minutes after dosing that persisted through 180 minutes.

CONCLUSION

In this small, selected group of healthy young adult subjects, a single dose of lormetazepam 1 mg did not affect psychomotor performance, assessed in terms of visual reaction times, compared with placebo.

Insomnia in General Practice

Insomnia is an extremely common condition with major social and economic consequences worldwide. Two large epidemiological studies (Morfeo 1 and Morfeo 2) recently performed in Italy provided much-needed novel data on the impact of insomnia in patients whose primary healthcare is provided by general practitioners (GPs). These studies found that insomnia is managed relatively well by GPs in Italy, although diagnosis and treatment can be compromised because of the lack of standardised criteria. Although a number of consensus reports on insomnia have been published, these are mainly highly specific documents that are difficult to implement in general practice. To address this, a consensus group involving 695 GPs and over 60 specialists from the Italian Association of Sleep Medicine was established. The major objectives of the consensus study were to establish basic knowledge for the diagnosis and treatment of insomnia, and to produce guidelines for the management of insomnia by GPs. This is the first time that GPs have been directly involved in producing insomnia guidelines of this type, and this approach reflects their pivotal role in the diagnosis and management of this condition. Participants were carefully selected to ensure adequate representation of sleep specialists and GPs, with the group being headed by a steering committee and an advisory board. Guideline statements were selected following careful literature review and were voted on using formalised consensus procedures. This review describes current views on the diagnosis and management of insomnia from the perspective of the GP. In addition, the results of the consensus study are presented. They include recognition of the following principles: (i) insomnia is a genuine pathology that must be appropriately diagnosed and treated; (ii) when concomitant pathologies are present, additional significance should be given to treatment of insomnia since it can influence prognosis of coexistent disorders; (iii) appropriate treatment should consider the cause of insomnia as well as the characteristics of available pharmacological agents; (iv) with regard to hypnotic drugs, preference should be given to medications with a short half-life in order to limit residual effects; (v) non-benzodiazepine hypnotics are preferred to classic benzodiazepines as they have higher selectivity and present a lower risk of undesirable effects; (vi) tablets are preferable to liquid preparations as they are less likely to lead to dependence and to overdosing by the patient; and (vi) once treatment has been initiated, insomnia patients should be carefully followed up. These statements provide much needed criteria for better management of insomnia by GPs in Italy.

Postural Instability and Consequent Falls and Hip Fractures Associated with Use of Hypnotics in the Elderly

The aim of this review is to establish the relationship between treatment with hypnotics and the risk of postural instability and as a consequence, falls and hip fractures, in the elderly. A review of the literature was performed through a search of the MEDLINE, Ingenta and PASCAL databases from 1975 to 2005. We considered as hypnotics only those drugs approved for treating insomnia, i.e. some benzodiazepines and the more recently launched 'Z'-compounds, i.e. zopiclone, zolpidem and zaleplon. Large-scale surveys consistently report increases in the frequency of falls and hip fractures when hypnotics are used in the elderly (2-fold risk). Benzodiazepines are the major class of hypnotics involved in this context; falls and fractures in patients taking Z-compounds are less frequently reported, and in this respect, zolpidem is considered as at risk in only one study. It is important to note, however, that drug adverse effect relationships are difficult to establish with this type of epidemiological data-mining. On the other hand, data obtained in laboratory settings, where confounding factors can be eliminated, prove that benzodiazepines are the most deleterious hypnotics at least in terms of their effects on body sway. Z-compounds are considered safer, probably because of their pharmacokinetic properties as well as their selective pharmacological activities at benzodiazepine-1 (BZ(1)) receptors. The effects of hypnotics on balance, gait and equilibrium are the consequence of differential negative impacts on vigilance and cognitive functions, and are highly dose- and time-dependent. Z-compounds have short half-lives and have less cognitive and residual effects than older medications. Some practical rules need to be followed when prescribing hypnotics in order to prevent falls and hip fractures as much as possible in elderly insomniacs, whether institutionalised or not. These are: (i) establish a clear diagnosis of the sleep disorder; (ii) take into account chronic conditions leading to balance and gait difficulties (motor and cognitive status); (iii) search for concomitant prescription of psychotropics and sedatives; (iv) use half the recommended adult dosage; and (v) declare any adverse effect to pharmacovigilance centres. Comparative pharmacovigilance studies focused on the impact of hypnotics on postural stability are very much needed.

Benzodiazépines : conséquences sur le fonctionnement mnésique des personnes âgées

Des études effectuées chez une population de volontaires sains en administration unique indiquent que les benzodiazépines (BZD) sont connues pour induire des déficits en mémoire. Cette population étudiée ne correspond toutefois pas avec celle qui consomme régulièrement ces substances soit les personnes âgées. Peu d’études ont été faites auprès de cette population cible afin de déterminer l’impact des BZD sur leur mémoire. Par contre, il existe des évidences suggérant aussi qu’il existe des conséquences importantes sur le fonctionnement de la mémoire des personnes âgées qui prennent des BZD. Les données actuelles vont même jusqu’à suggérer que les BZD exacerbent les déficits de mémoire chez les personnes âgées. Cela pourrait même constituer un facteur de risque précipitant le déclin cognitif et augmentant ainsi le risque de développer une démence.

Comparative pharmacokinetics and pharmacodynamics of short-acting hypnosedatives: zaleplon, zolpidem and zopiclone

Benzodiazepines have historically been the mainstay of treatment for sleeping disorders, yet they have many shortcomings. A new group of sedative hypnotic agents has been developed for this purpose. Similar to the benzodiazepines, zaleplon, zolpidem and zopiclone have activity at the GABA receptor complex, yet they appear to have more selectivity for certain subunits of the GABA receptor. This produces a clinical profile that is more efficacious with fewer side effects. Zaleplon, zolpidem and zopiclone are structurally distinct. Due to variation in binding to the GABA receptor subunits, these three compounds show subtle differences in their effect on sleep stages, and as antiepileptics, anxiolytics and amnestics. The duration of action of zaleplon, zolpidem and zopiclone can be related to their individual pharmacokinetic profile, which subsequently determines the time course of drug effect. Each of these compounds has a unique pharmacokinetic profile with different bioavailability, volume of distribution and elimination half-lives. Zaleplon has a rapid elimination so there are fewer residual side effects after taking a single dose at bedtime. By comparison, zolpidem and zopiclone have a more delayed elimination so there may be a prolonged drug effect. This can result in residual sedation and side effects but may be useful for sustained treatment of insomnia with less waking during the night. There are also differences in potency based on plasma concentrations suggesting that there are differences in binding to the GABA receptor complex. Although zaleplon has a much lower bioavailability (30%), the treatment dose is similar to zolpidem and zopiclone (bioavilaibility of 70%) because of the increased potency of zaleplon. The pharmacokinetics and pharmacodynamics of zaleplon, zolpidem and zopiclone are significantly different from benzodiazepines. The new drugs are sufficiently unique from each other to allow customisation of treatment for various types of insomnia. While zaleplon may be best indicated for the delayed onset of sleep, zolpidem and zopiclone may be better indicated for maintaining a complete night's sleep. Only the patient's symptoms and response to treatment will dictate the best course of treatment.

Windows of detection of zolpidem in urine and hair: application to two drug facilitated sexual assaults

A LC-MS/MS method for the detection of zolpidem in hair was developed to detect this drug after a single dose in possible drug facilitated sexual assaults. To determine the window of detection of zolpidem in both urine and hair, three volunteers received a 10 mg dose. Urine specimens were collected each 12 h for 144 h. Hair was sampled 3-5 weeks after exposure. Hair and urine extracts were separated on a Xterra MS C18 column using a gradient of acetonitrile and formate buffer. For each compound, detection was related to two daughter ions. Zolpidem was detected for up to 60 h in urine with peak concentrations obtained at 12 h. A single exposure to zolpidem was detected in hair at concentrations ranging from 1.8 to 9.8 pg/mg. Hair analysis was applied to two possible criminal cases. In the first case, zolpidem tested positive in the corresponding hair segment at 4.4 pg/mg. In the other case, zolpidem was detected in all the segments analyzed, demonstrating likely previous drug use in addition to recent exposure associated with a positive blood result.

Pediatric sleep pharmacology: you want to give my kid sleeping pills?

There is a need for greater information about the pharmacologic management of sleep disorders in children. Pharmacologic guidelines must be developed specifically for sleep disorders in children. Ideally, these guidelines should be approved by the Food and Drug Administration for a specific sleep disorder or for the pediatric age range. This approval prevents physicians from being forced to prescribe medications as an "off label" indication. Development of easy-to-swallow, chewable, or liquid forms of these medications would be well received by parents everywhere. When these are not available, instructions for compounding these medications into a suspension by pharmacists are needed. Integration of behavioral and pharmacologic treatments may yield better patient outcomes. This approach requires pediatricians to have a comprehensive understanding of clinical sleep disorders in children. Training programs should play the lead role in enhancing pediatricians' knowledge of the pharmacologic treatment of sleep disorders in children.

Treating Sleep Problems in Patients with Burn Injuries: Practical Considerations

Sleep disorders are a frequent but under-addressed complication of burn injuries. Burn injuries can potentially disrupt sleep for a variety of reasons, including the physiological effects of trauma as well as ramifications of treatment (ie, intensive care unit environment, pain, itching, medications). The literature on sleep disorders and burn injuries is reviewed, and suggestions for treatment are provided. Treatment is divided into two major types: nonpharmacologic and pharmacologic. Nonpharmacologic treatment, also referred to as behavioral techniques, may include any one or combination of the following: sleep hygiene, stimulus control, sleep restriction, relaxation techniques, cognitive, and light therapy. Pharmacologic therapies may include hypnotics (benzodiazepine, nonbenzodiazepine, or benzodiazepine receptor agonists), antidepressants, over-the-counter preparations, hormone replacement therapy, herbs, and melatonin.