The effects of a single night's dosing with triazolam on sleep the following night

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.

REM sleep effects as a biomarker for the effects of antidepressants in healthy volunteers

The potential use of rapid eye movement (REM) sleep effects as a biomarker for the therapeutic effects of antidepressants in healthy volunteers is reviewed. A literature search was performed to select studies investigating the effects of antidepressants on REM sleep. To assess the specificity of REM sleep effects as a biomarker, the effects of other central nervous system drugs on REM sleep were also investigated. A significant REM sleep reduction was shown for 16 of 21 investigated antidepressants after single-dose (mean reduction 34.1%) and for 11/13 drugs after multiple-dose administration (mean reduction 29.2%). The median increase in REM latency was approximatety 60% after single- or multiple-dose administration. REM sleep effects were linearly normalized to therapeutic doses, by dividing the REM sleep effect by the investigated dose and multiplying by the therapeutic dose. Normalized REM sleep effects were highly variable (range -27.0% to 81.8% for REM sleep; range -17.0% to 266.3% for REM latency) and demonstrated no relationship with relevant pharmacological properties of the investigated drugs. No quantifiable dose-response relationship could be constructed after single and multiple dose administration. REM sleep effects were not specific for antidepressants. Benzodiazepines, for example, caused an average dose normalized REM sleep reduction of 8.7% and a median 8.6% increase of REM latency. This review demonstrates that although REM sleep effects occur with most of the antidepressants, it is by itself of limited value as a biomarker for antidepressant action. The specificity for antidepressants is limited, and it does not show a quantitative dose-response relationship to antidepressant agents. This is at least partly due to the complex relationships between drug pharmacokinetics and the variable time course of REM and other sleep stages throughout the night. Models that take these complex relationships into account may provide more comprehensive and quantifiable results.

Non-benzodiazepines for the treatment of insomnia

Benzodiazepine hypnotics, the mainstay of pharmacological treatment for insomnia, have been associated with altered sleep architecture, psychomotor and memory impairment, rebound insomnia, withdrawal effects, tolerance, dependence, abuse potential and respiratory depression. Non-benzodiazepines, such as zolpidem, zopiclone and zaleplon, demonstrate hypnotic efficacy similar to that of benzodiazepines along with excellent safety profiles. Non-benzodiazepines generally cause less disruption of normal sleep architecture than benzodiazepines. Psychomotor and memory impairment may be less problematic with non-benzodiazepines, especially when compared to longer-acting benzodiazepines. Rebound insomnia and withdrawal symptoms occur infrequently upon discontinuation of non-benzodiazepines and may be less common and milder than those seen upon discontinuation of some benzodiazepines. For the long-term treatment of insomnia, which is generally not recommended, zolpidem and zopiclone are particularly good options because they do not develop tolerance rapidly and have a low abuse potential. Limited data indicate that zaleplon has low tolerance and abuse potential, although further experience is needed to determine its long-term efficacy and safety profile. Since non-benzodiazepines produce minimal respiratory depression, they may be safer than benzodiazepines in patients with respiratory disorders. The choice of which hypnotic to use should be based on the patient's primary sleep complaint, health history, adverse effects and cost.

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.

Triazolam in Alzheimer's disease: pilot study on sleep and memory effects

We examined the effects on sleep and memory of a nighttime dose of triazolam, 0.125 mg, in seven subjects with Alzheimer's disease (AD) who were reported by caregivers to be frequently up at night. Subjects were admitted to an intermediate care hospital ward for the 8-day ABA design protocol (placebo baseline-drug-placebo washout). Drug or placebo was given each evening at 2100 h. Sleep was assessed with a wrist-worn activity monitor. Memory was evaluated using a computerized delayed-matching-to-sample (DMTS) task administered at 0800 and 2130 h. Triazolam had no significant effects on total sleep time at night, latency to sleep onset, number of arousals, or time asleep during the day. DMTS performance was significantly worse at night compared to morning during baseline, but there were no significant drug effects. Our results suggest the standard geriatric dose of triazolam, 0.125 mg, may not be an effective hypnotic in AD patients with disrupted sleep, but neither does it substantially worsen the recent memory deficits of AD.

Rebound insomnia and newer hypnotics

The prescription of hypnotics, mostly benzodiazepines, continues at a high level. One problem with their use is rebound insomnia: upon discontinuation sleep worsens compared with pretreatment levels. Factors influencing rebound include the type of subject, the duration of action of the hypnotic, the dosage and perhaps duration of treatment. The detection of rebound requires both sleep-laboratory and clinical studies with night-by-night analyses of individual patient data. This review concentrates on the newer compounds, (quazepam and zolpidem) which act selectively on subtypes of benzodiazepine receptors or bind atypically (zopiclone). It concludes that present evidence, while limited, is consistent with claims of less rebound potential than older benzodiazepine hypnotics of equivalent duration of action. Nevertheless, further rigorous studies are essential before these claims can be totally accepted.

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.