Differential effects of flunitrazepam on human sleep in combination with flumazenil

Arachis hypogaea L. stem and leaf extract improves the sleep behavior of pentobarbital-treated rats

This study was conducted to evaluate the sedative effects of Arachis hypogaea L. stem and leaf extract (AHSLE) and determine its effect pathways through γ-aminobutyric acid (GABA)-gated channels on male Sprague-Dawley rats treated with pentobarbital. AHSLE was obtained from 98°C water (3 h, extracted twice). AHSLE and flumazenil (a GABA type A receptor antagonist) were administered to the rats orally, whereas pentobarbital sodium and muscimol (a GABA type A receptor agonist) were administered intraperitoneally (i.p.). The results demonstrated that AHSLE decreased sleep latency and increased sleep time in pentobarbital-treated rats (50 mg/kg, i.p.). The coadministration of AHSLE and muscimol (0.05 mg/kg) significantly increased sleep time and reduced sleep latency in pentobarbital-treated rats and these actions were significantly antagonized by flumazenil at a dose of 3.5 mg/kg. These results indicated that AHSLE improved the sleep behavior in pentobarbital-treated rats, possibly through GABA-gated channel-related mechanisms.

Depressive effects on the central nervous system and underlying mechanism of the enzymatic extract and its phlorotannin-rich fraction from Ecklonia cava edible brown seaweed

Marine plants have been reported to possess various pharmacological properties; however, there have been few reports on their neuropharmacological effects. Terrestrial plants have depressive effects on the central nervous system (CNS) because of their polyphenols which make them effective as anticonvulsants and sleep inducers. We investigated in this study the depressive effects of the polyphenol-rich brown seaweed, Ecklonia cava (EC), on CNS. An EC enzymatic extract (ECEE) showed significant anticonvulsive (>500 mg/kg) and sleep-inducing (>500 mg/kg) effects on the respective mice seizure induced by picrotoxin and on the mice sleep induced by pentobarbital. The phlorotannin-rich fraction (PTRF) from ECEE significantly potentiated the pentobarbital-induced sleep at >50 mg/kg. PTRF had binding activity to the gamma aminobutyric acid type A (GABA(A))-benzodiazepine (BZD) receptors. The sleep-inducing effects of diazepam (DZP, a well-known GABA(A)-BZD agonist), ECEE, and PTRF were completely blocked by flumazenil, a well-known antagonist of GABA(A)-BZD receptors. These results imply that ECEE produced depressive effects on CNS by positive allosteric modulation of its phlorotannins on GABA(A)-BZD receptors like DZP. Our study proposes EC as a candidate for the effective treatment of neuropsychiatric disorders such as anxiety and insomnia.

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.

Effect of flumazenil-augmentation on microsleep and mood in depressed patients during partial sleep deprivation

The antidepressive effect of sleep deprivation (SD) in depressed patients disappears after sleep of the recovery night and after early morning naps. Both can provoke a rapid relapse into depression in SD-responders. In addition, the occurrence of short episodes of sleep (termed microsleep, MS) during partial SD (PSD) is associated with SD-nonresponse, suggesting that MS during the time awake may be related to relapse or PSD-nonresponse. The GABA-benzodiazepine receptor antagonist flumazenil augments vigilance and reduces NonREM-sleep pressure in early morning recovery sleep in volunteers after SD. Therefore, in this study 27 patients with major depression were subjected to a PSD. In a double blind randomized design either flumazenil or placebo was orally applied during PSD in order to examine whether the application of flumazenil reduces sleep propensity and thus, increases antidepressant efficacy of PSD. EEG was registered continuously for 60h by a portable device for the assessment of microsleep episodes at baseline and during PSD. Flumazenil application significantly suppressed frequency and total amount of MS. While the antidepressant efficacy of PSD was not different between flumazenil and placebo during PSD, the subjective mood improved after the recovery night in patients treated with flumazenil. It is concluded that GABAergic mechanisms are involved in the regulation of MS during PSD, which may be related to a mood stabilizing effect after the recovery night. However, the mechanisms underlying the association between the occurrence of MS during PSD and mood variation have to be further clarified.

Extract of Ganoderma lucidum potentiates pentobarbital-induced sleep via a GABAergic mechanism

Ganoderma lucidum has been used for the treatment of a variety of diseases. For the first time here we report a detailed study on the mechanisms and effects of G. lucidum aqueous extract (GLE) on sleep and its sedative activity. GLE showed no effects on sleep architecture in normal rats at doses of 80 and 120 mg/kg. However, GLE significantly decreased sleep latency, increased sleeping time, non-REM sleep time and light sleep time in pentobarbital-treated rats. Suppression of locomotor activity in normal mice induced by GLE was also observed. Flumazenil, a benzodiazepine receptor antagonist, at a dose of 3.5 mg/kg showed a significant antagonistic effect on the shortening in sleep latency, increase in sleeping time, non-REM sleep time or light sleep time in pentobarbital-treated rat induced by GLE. Significant effect was also observed with GLE on delta activity during non-REM sleep and flumazenil did not block this effect. In conclusion, GLE may be a herb having benzodiazepine-like hypnotic activity at least in part.

Effects of some H1-antagonists on the sleep-wake cycle in sleep-disturbed rats

The present study was undertaken to investigate the effects of some H(1)-antagonists on the sleep-wake cycle in sleep-disturbed rats in comparison with those of nitrazepam. Electrodes were chronically implanted into the frontal cortex and the dorsal neck muscle of rats for the electroencephalogram (EEG) and electromyogram (EMG), respectively. EEG and EMG were recorded with an electroencephalograph. SleepSign ver. 2.0 was used for EEG and EMG analysis. The total times of waking, non-rapid eye movement (non-REM), and rapid eye movement (REM) sleep were measured from 10:00 to 16:00. Nitrazepam showed a significant decrease in sleep latency, total waking time, and delta activity and an increase in the total non-REM sleep time. A significant decrease in the sleep latency was observed with diphenhydramine, chlorpheniramine, and cyproheptadine. Cyproheptadine also caused a significant decrease in the total waking time and increases in total non-REM sleep time, REM sleep time, slow wave sleep, and delta activity, although no remarkable effects were observed with diphenhydramine and chlorpheniramine. In conclusion, cyproheptadine can be useful as a hypnotic, having not only sleep inducing-effects, but also sleep quantity- and quality-increasing effects.

Effects of kava-kava extract on the sleep-wake cycle in sleep-disturbed rats

RATIONALE

Kava-kava extract may be useful as an herbal medicine for treatment of insomnia and anxiety.

OBJECTIVES

The present study was undertaken to investigate the effects of kava-kava extract on the sleep-wake cycle in comparison with that of flunitrazepam using sleep-disturbed rats.

METHODS

Electrodes for measurement of electroencephalogram (EEG) and electromyogram (EMG) were implanted into the frontal cortex and the dorsal neck muscle of rats. EEG and EMG were recorded with an electroencephalogram. SleepSign ver.2.0 was used for EEG and EMG analysis. Total times of wakefulness, non-rapid eye movement (non-REM) and REM sleep were measured from 09:00 to 15:00.

RESULTS

A significant shortening of the sleep latency in sleep-disturbed rats was observed following the administration of kava-kava extract at a dose of 300 mg/kg, while no effects were observed on the total waking and non-REM sleep time. On the other hand, flunitrazepam showed a significant shortening in sleep latency, decrease in total waking time and increase in total non-REM sleep time. Although the effects of flunitrazepam were antagonized by the benzodiazepine receptor antagonist flumazenil, the effect of kava-kava extract was not antagonized by flumazenil. Kava-kava extract showed a significant increase in delta activity during non-REM sleep in sleep-disturbed rats, whereas a significant decrease in delta power during non-REM sleep was observed with flunitrazepam. Flumazenil caused no significant effect on the changes in delta activity induced by both kava-kava extract and flunitrazepam.

CONCLUSIONS

Kava-kava extract is an herbal medicine having not only hypnotic effects, but also sleep quality-enhancement effects.

Chronic benzodiazepine usage and withdrawal in insomnia patients

We studied the sleep of patients with insomnia during continuous and very long-term use of benzodiazepines (BZDs), and after withdrawal. A group of 25 patients (mean age 44.3+/-11.8 years) with persistent insomnia, who had been taking BZDs nightly for 6.8+/-5.4 years was selected. The control group was comprised of 18 age-matched healthy individuals. Sleep stage parameters were analyzed during Night 1 (while taking BZDs), Night 2 (first night after completing BZD withdrawal), and Night 3 (15 days after gradual BZD withdrawal). Sleep data for control subjects was monitored in parallel. Sleep EEGs of the patients were analyzed using Period Amplitude Analysis (PAA), during Nights 1 and 3 only. During BZD use, a significant reduction of Total Sleep Time (TST) and increased sleep latency were found in the insomniac group when compared to controls. We found an increase in stage 2 non-REM (NREM) sleep, and a reduction in Slow Wave Sleep (SWS) when comparing to night 3 (after withdrawal). Sleep EEGs analysis showed an increase in sigma band and decrease in delta count in stages 2, 3, 4 NREM and REM sleep in the BZD group when comparing to night 3 (after withdrawal). During the BZD withdrawal period, six out of nine subjects taking lorazepam failed withdrawal. In the remaining 19 subjects, gradual withdrawal of BZDs was associated with immediate worsening of nocturnal sleep, as indicated by sleep parameters. However, 15 days after withdrawal (Night 3), some of the sleep structure parameters of patients were not significantly different from baseline (while taking BZDs), except for a significant increase in SWS and in delta count throughout most sleep stages, and a decrease in stage 2 NREM sleep. These values were not different from those shown by control subjects. REM sleep parameters showed no significant variation across the experimental conditions. Subjective sleep quality was significantly improved on Night 3 compared with Night 1.

CONCLUSIONS

Chronic intake of BZDs may be associated with poor sleep in this population. A progressive 15-day withdrawal did not avoid an immediate worsening of sleep parameters. But at the end of the protocol, SWS, delta count, and sleep quality were improved compared to those recorded during the chronic BZD intake, despite the lack of change in sleep efficiency.

Ceiling and floor effects in sleep research

Ceiling and floor effects dictate that the efficacy of sleep-promoting stimuli should be proportional to the degree of pre-stimulus sleep impairment. This review addressed CF effects in polysomnographic research involving hypnotic drugs and exercise. Correlations of placebo/baseline levels of sleep with changes in sleep following hypnotic or exercise treatment were assessed across both literatures. CF effects were further addressed by comparing sleep-promoting effects of hypnotics vs exercise, after ANCOVA control for substantial baseline differences reported in studies of these stimuli. Significant correlations between placebo-baseline levels and sleep changes were observed following both hypnotic and exercise stimuli. Indeed, approximately 60% of the variance in improvement in sleep latency (SOL), wakefulness after sleep onset (WASO) and total sleep time (TST) following hypnotic treatment was associated with differences in baseline levels. ANCOVAs revealed significantly greater decreases in SOL and WASO following hypnotics compared with exercise. However, no significant difference between stimuli was found for TST, and exercise elicited a significantly greater increase in slow wave sleep. Similar results were found when a comparison between hypnotics and exercise was limited to good sleepers. The results show powerful CF influences on sleep responses to hypnotics and exercise and suggest a need for comparing these treatments in poor sleepers.

Can valerian improve the sleep of insomniacs after benzodiazepine withdrawal?

PURPOSE

The authors studied the sleep of patients with insomnia who complained of poor sleep despite chronic use of benzodiazepines (BZDs). The sample consisted of 19 patients (mean age 43.3+/-10.6 years) with primary insomnia (DSM-IV), who had taken BZDs nightly, for 7.1+/-5.4 years. The control group was composed of 18 healthy individuals (mean age 37+/-8 years). Sleep electroencephalogram (EEG) of the patients was analyzed with period amplitude analysis (PAA) and associated algorithms, during chronic BZD use (Night 1), and after 15 days of a valerian placebo trial (initiated after washout of BZD, Night 2). Sleep of control subjects was monitored in parallel.

RESULTS

Valerian subjects reported significantly better subjective sleep quality than placebo ones, after BZD withdrawal, despite the presence of a few side effects. However, some of the differences found in sleep structure between Night 1 and Night 2 in both the valerian and placebo groups may be due to the sleep recovery process after BZD washout. Example of this are: the decrease in Sleep Stage 2 and in sigma count; the increase in slow-wave sleep (SWS), and delta count, which were found to be altered by BZD ingestion. There was a significant decrease in wake time after sleep onset (WASO) in valerian subjects when compared to placebo subjects; results were similar to normal controls. Nonetheless, valerian-treated patients also presented longer sleep latency and increased alpha count in SWS than control subjects.

CONCLUSIONS

The decrease in WASO associated with the mild anxiolytic effect of valerian appeared to be the major contributor to subjective sleep quality improvement found after 2-week of treatment in insomniacs who had withdrawn from BDZs. Despite subjective improvement, sleep data showed that valerian did not produce faster sleep onset; the increase in alpha count compared with normal controls may point to residual hyperarousabilty, which is known to play a role in insomnia. Nonetheless, we lack data on the extent to which a sedative drug can improve alpha sleep EEG. Thus, the authors suggest that valerian had a positive effect on withdrawal from BDZ use.

Effects of hypnotics on the sleep EEG of healthy young adults: new data and psychopharmacologic implications

Benzodiazepine hypnotics increase NREM sleep and alter its EEG by reducing delta (0.3-3 Hz) and increasing sigma (12-15 Hz) and beta (15-23 Hz) activity. We tested whether the nonbenzodiazepine hypnotic, zolpidem (10 mg), produced the same pattern of sleep and EEG changes as two "classical" benzodiazepines, triazolam (0.25 mg) and temazepam (30 mg). Sleep EEG of 16 subjects was analyzed with period amplitude analysis for 3 nights during drug administration or placebo. The effects of zolpidem were in the same direction but generally of smaller magnitude than those of the classical benzodiazepines. These differences are more likely the result of non-equivalent dosages than different pharmacologic actions. Period amplitude analysis showed that the decreased delta activity resulted mainly from a decrease in wave amplitude. In contrast, the increased sigma and beta activity were produced by increased wave incidence. Delta suppression increased with repeated drug administration but sigma and beta stimulation did not. While these findings have little relevance for the clinical choice of hypnotics they may hold important implications for the brain mechanisms involved in hypnotic tolerance and withdrawal delirium.

Independence of sleep EEG responses to GABAergic hypnotics: biological implications

GABAergic hypnotics are known to depress non-rapid eye movement delta and rapid eye movements and to stimulate non-rapid eye movement sigma (spindles) and beta EEG. This study addressed the question of whether the magnitudes of these effects are significantly correlated. Data were from a study in 16 normal subjects whose sleep was recorded for five nights under placebo and for three nights each under zolpidem (10 mg), triazolam (0.25 mg) and temazepam (30 mg). EEG was analyzed with both period-amplitude and power spectral (FFT) analysis. The magnitudes of the EEG and eye movement density responses were not significantly correlated for any of the three drugs. It is therefore unlikely that sleep responses to GABAergic drugs can be explained by the common cellular action (increased chloride conductance) of these drugs. We suggest that the sleep EEG responses are manifestations of complex (but consistent) interactions of excitation and inhibition in large brain systems although certain aspects of these responses (e.g. the different time courses of delta vs sigma and eye movement responses) may reflect molecular adaptations. A separate observation in this study was the strong traitlike characteristics of the sleep variables studied. These variables were highly correlated across nights of baseline sleep; in addition, individual differences in baseline sleep were significantly retained on the third night of temazepam administration.

Zolpidem and sleep deprivation: different effect on EEG power spectra

To study the role of GABA-ergic mechanisms in sleep regulation, the combined action of 40 h sleep deprivation and either 20 mg zolpidem or placebo on the sleep electroencephalogram (EEG) were investigated by quantitative EEG analysis in eight young men who participated in a positron emission tomography study. Compared with baseline, sleep deprivation increased low-frequency (1.25-7.0 Hz) EEG power in non-rapid eye movement (NREM) sleep in the placebo night. After administration of zolpidem, power in the 3.75-10.0 Hz range and 14. 25-16.0 Hz band was reduced. The largest decrease was observed in the theta band. Comparison with placebo revealed that zolpidem attenuated power in the entire 1.75-11.0 Hz range. The plasma concentration of zolpidem at 4.5 h after intake showed a positive correlation with the drug-induced difference in power from placebo in the 14.25-16.0 Hz band. Regional EEG analysis based on bipolar derivations along the antero-posterior axis disclosed, for NREM sleep, a drug-induced posterior shift of power in the frequency range of 7.75-9.75 Hz. Zolpidem did not affect rapid eye movemnt sleep spectra. We conclude that sleep deprivation and agonistic modulation of GABAA receptors have separate and additive effects on power spectra and that their effects are mediated by different neurophysiological mechanisms.

High doses of systemic DHEA-sulfate do not affect sleep structure and elicit moderate changes in non-REM sleep EEG in rats

The hormone dehydroepiandrosterone (DHEA) and its metabolite DHEA-sulfate (DHEAS) occur in huge quantities in the plasma as well as in the brain of vertebrates. To investigate whether DHEAS modulates sleep-wake behavior, we assessed the sleep response to three doses (25, 50, and 100 mg/kg) of intraperitoneally administered DHEAS, mixed with oil, in 8 rats. DHEAS injections produced dose-dependent and long-lasting elevations in the plasma levels of both DHEAS and DHEA. DHEAS administration did not affect sleep time and architecture but exerted persistent effects on the electroencephalogram (EEG) within non-rapid eye movement sleep: 50 mg/kg DHEAS significantly augmented EEG power in the frequency range of sleep spindles, and 100 mg/kg DHEAS depressed EEG power in the slow-wave frequency bands. The findings indicate that DHEAS changes the sleep EEG in a dose-dependent way, possibly through a modulation of GABA- and glutamate-induced currents.

Polysomnographic effects of hypnotic drugs. A review

This review aims at providing a critical assessment of the effects of the most widely used benzodiazepine (flurazepam, flunitrazepam, temazepam, triazolam) and non-benzodiazepine (zopiclone and zolpidem) hypnotic drugs, based on the recording of polysomnographic variables. In the light of newly acquired neurophysiological data on the microstructure of sleep, this paper reconsiders the problem of insomnia and the current ideas on polysomnography and hypnotic drugs.

Flunitrazepam effects on human sleep EEG spectra: Differences in NREM, REM and individual responses

Flunitrazepam (FNZ) (4mg), an intermediate type benzodiazepine (BDZ) hypnotic, was administered orally to five healthy male subjects (Ss) for seven consecutive nights. Sleep EEG from the baseline night (BLN), the initial drug night (IDN), the fourth and the seventh drug nights (4DN, 7DN) was subjected to fast Fourier transform (FFT) analysis. During NREM sleep of 4DN and 7DN the sigma band (11.0-12.5 Hz) activity was similarly enhanced in every S. In REM of 4DN and 7DN beta band (23.0-29.0 Hz) was enhanced, but with larger variations among Ss. High intra-individual consistency of the relative EEG power patterns on 4DN and 7DN was observed. These results suggest that 1) EEG responses to FNZ are different in sleep states; explorations of these differences may provide better understandings of sleep mechanisms, and 2) individual variations in EEG responses may reflect individual variations of the BDZ receptor system. These methods may be useful for exploring receptor changes in neuropsychiatric disorders.

Bretazenil modulates sleep EEG and nocturnal hormone secretion in normal men

Preclinical data suggest that the imidazodiazepinone derivative bretazenil (Ro 16-6028) has anxiolytic and anticonvulsant properties with only weak sedative effects. We examined the influence of oral administration of 1 mg bretazenil on the sleep EEG and the concomitant nocturnal secretion of cortisol, growth hormone and prolactin in ten healthy young men. After bretazenil we found a significant increase in stage 2 sleep and a significant reduction in stage 3 sleep. REM latency was prolonged. Spectral analysis of sleep-EEG power revealed a decrease in delta and in theta power and an increase in sigma power. We found no significant influence on sleep onset latency or on intermittent wakefulness. Bretazenil prompted a significant decrease in cortisol secretion and a significant increase in prolactin release. It had no major influence on growth hormone secretion.

Effects of flumazenil on recovery sleep and hormonal secretion after sleep deprivation in male controls

The effects of flumazenil, a benzodiazepine antagonist, on the sleep electroencephalogram (EEG) and neuroendocrine secretion in early morning recovery sleep (0500-0800 hours) following sleep deprivation (SD; 2300-0500 hours) were studied in seven healthy men. SD induced an increase in slow wave sleep (SWS), a decrease in sleep onset latency (SOL), an enhancement of EEG delta and theta power in non-rapid-eye-movement sleep, an increase in plasma human growth hormone (GH) concentration, and a decrease in plasma cortisol levels in recovery sleep (0500-0800 hours). Plasma GH, but neither plasma cortisol nor adrenocorticotrophic hormone (ACTH) concentration was attenuated during SD as compared to sleep (2300-0445 hours). The administration of flumazenil (3 x 1 mg intravenously) during recovery sleep resulted in an inhibition in SWS, an increase in stage 2 sleep, a selective reduction in delta and theta power, and a tendency to prolongation of SOL. Plasma GH concentration was decreased but plasma cortisol and ACTH remained unaffected. Since the SD-induced changes in sleep EEG and plasma GH secretion were antagonized by flumazenil, it is suggested that electrophysiological and hormonal effects of SD are mediated at least in part through GABAergic mechanisms.

Effects of ZK 93,426, a beta-carboline benzodiazepine receptor antagonist on night sleep pattern in healthy male volunteers

The beta-carboline ZK 93,426, a benzodiazepine-antagonist with weak inverse agonist activity, was administered intravenously to human volunteers at a dose of 0.04 mg/kg when they initially reached slow-wave sleep during their night's sleep. Eight subjects, subjected to half a night of sleep withdrawal, took part in the study, which was performed according to a double-blind, placebo-controlled, cross-over design. Sleep parameters as determined by electroencephalography, actometry (wrist actometer) and temperature (rectal thermometer) were monitored for the whole night. Vital functions (blood pressure and heart rate) as well as subjectively experienced effects via visual analogue scales were evaluated and blood samples for hormone plasma level estimation were taken before and after sleep. ZK 93,426 was well tolerated. Sleep parameters were reduced under the influence of the drug indicating a stimulant effect. Slow wave sleep (sleep stages 3 and 4) was significantly reduced in favour of light sleep stages 1 and 2 during the first 30 min after the administration of ZK 93,426 (P = 0.02). In keeping with these findings subjects exhibited a significantly (P < 0.02) elevated number and intensity of movements during the first 90 min after the beta-carboline injection. Effects on self-ratings, in body temperature and on hormonal changes were not found. It is assumed that the benzodiazepine-antagonist ZK 93,426 is able to induce activation and disturb sleep via modulation of GABAergic transmission mainly by benzodiazepine receptor blocking properties.(ABSTRACT TRUNCATED AT 250 WORDS)

Flumazenil exerts intrinsic activity on sleep EEG and nocturnal hormone secretion in normal controls

The physiological function of benzodiazepine (BDZ) receptors includes regulation of sleep and neuroendocrine activity. Most of the pharmacological effects of BDZ are blocked by flumazenil. However, recent neurological and behavioral studies suggest that flumazenil has its own central intrinsic activity. This issue was addressed in a study of the sleep EEG and the nocturnal secretion of growth hormone and cortisol in ten normal male controls, who were given flumazenil either alone or in combination with the BDZ agonist midazolam, placebo and midazolam alone. Flumazenil prompted an increase in sleep onset latency, a decrease in slow wave sleep and an increase in wakefulness. Plasma cortisol concentrations after flumazenil administration were lower than after midazolam. Both flumazenil and midazolam decreased nocturnal growth hormone secretion. After simultaneous application of both BDZ receptor ligands the growth hormone blunting was amplified. Our study demonstrates that at the level of the sleep EEG and neuroendocrine activity flumazenil is capable of exerting both agonistic and inverse agonistic or antagonistic effects.

Clinical applications of cyclic alternating pattern

Sleep-related disorders are revisited in the light of the physiological modality of NREM sleep expressed by the cyclic alternating pattern (CAP). Owing to its fluctuating properties on vigilance, muscle tone, and vegetative activities, CAP represents a highly favorable condition for the occurrence of interictal generalized and focal lesional EEG discharges, for motor seizures, and for periodic jerks in nocturnal myoclonus. All these manifestations are significantly associated with the components of activation during CAP, i.e., the A phases. On the contrary, the B phases of CAP appear chronologically linked to inhibitory phenomena in epileptic patients and in nocturnal myoclonus. The two phases of CAP seem especially involved in sleep apnea syndrome, where respiration is interrupted during a phase B and restored during a phase A. CAP rate, that measures the effort of the brain to maintain sleep, is increased by all conditions that induce vigilance instability such as noise, clinical insomnia, interictal EEG paroxysms, nocturnal seizures, periodic leg movements, and in certain extreme pathologic conditions such as Creutzfeldt-Jakob disease and stage 2 coma.

Effects of zolpidem and flunitrazepam on nocturnal sleep of women subjectively complaining of insomnia

Eighteen non-pregnant woman complaining about insomnia were polysomnographically investigated for 3 nights with weekly intervals. They received placebo, 2 mg flunitrazepam or 10 mg zolpidem according to a cross-over double blind design. The patients were selected by general practitioners on the basis of subjective complaints. Zolpidem is a recently introduced short-acting imidazopyridine hypnotic, binding to a subunit of the benzodiazepine 1 receptor. Flunitrazepam is a well-known hypnotic, binding to both the benzodiazepine 1 and 2 receptor subtypes. Objective recording did not substantiate the subjective complaint of insomnia. Sleep patterns during placebo differed only little from that expected from age matched healthy persons. Both flunitrazepam and zolpidem significantly shortened sleep onset (5 min of continuous sleep beginning with NREM 1 sleep). The sleep composition following flunitrazepam was characterized by an increase in NREM 2, a prolongation of the time of REM sleep, a reduction of REM sleep and an increase in NREM 3-4 sleep during the first 2 h of sleep. The sleep composition following zolpidem resembled more than seen in persons without sleep complaints. However, as compared to placebo, there was a decrease of the time spent awake during sleep and an increase in NREM 3-4 during the first 2 of sleep.

Ultradian dynamics of sleep after a single dose of benzodiazepine hypnotics

A single bedtime dose of the benzodiazepine hypnotics, flunitrazepam (2 mg), triazolam (0.5 mg) or flurazepam (30 mg), was administered to young, healthy subjects. Abortive first rapid eye movement sleep (REMS) episodes, characterized by a low level of EEG slow-wave activity (spectral power density in the 0.75-4.5 Hz band) without rapid eye movements and/or muscle atonia, were more frequent in the drug night than in the placebo night or in the drug-free night following upon the drug night. The benzodiazepine hypnotics depressed slow-wave activity in non-REM sleep (NREMS) in the drug night and the subsequent drug-free night. However, the typical declining trend of slow-wave activity over the first three NREMS-REMS cycles, and the cyclic ultradian pattern of slow-wave activity were little affected by the hypnotics. The results indicate that benzodiazepine hypnotics depress the generation of slow EEG waves without disrupting the homeostatic and ultradian processes of sleep regulation.

Hypnotic action of flunitrazepam is reversed by proglumide in rats

1. Caerulein, an analogue of cholecystokinin (CCK-8), like CCK-8, has been shown to produce hypnotic effects similar to those of benzodiazepine (flunitrazepam). 2. Proglumide antagonizes the action of CCK-8 and of its analogue. 3. The aim of the present study was to demonstrate whether proglumide would affect the potent hypnotic action of flunitrazepam in rats. 4. The association of proglumide with flunitrazepam suppress the increase of total sleep time and slow wave sleep seen after flunitrazepam alone. Proglumide alone has no effect on sleep stages. The authors report here for the first time that the hypnotic action of flunitrazepam is antagonized by proglumide in rat.

Hypnotics and sleep physiology: a consensus report. European Sleep Research Society, Committee on Hypnotics and Sleep Physiology

The effects of hypnotics on descriptive and functional aspects of electrophysiological sleep parameters are assessed in this report. Because of the arbitrary definition of some of the criteria underlying the conventional sleep stage scoring procedure, computer-aided methods of EEG analysis have become increasingly important for recording and interpreting pharmacological effects on sleep. Of particular interest are the changes of EEG slow-wave activity, since this parameter varies as a function of prior sleep and waking. Several types of interaction between hypnotics and sleep regulation are discussed, some recent pharmacological developments are highlighted, and some common problems in clinical trials are specified.