Intermediate use of triazolam: a sleep laboratory study

Mechanisms Underlying Tolerance after Long-Term Benzodiazepine Use: A Future for Subtype-Selective GABA(A) Receptor Modulators?

Despite decades of basic and clinical research, our understanding of how benzodiazepines tend to lose their efficacy over time (tolerance) is at least incomplete. In appears that tolerance develops relatively quickly for the sedative and anticonvulsant actions of benzodiazepines, whereas tolerance to anxiolytic and amnesic effects probably does not develop at all. In light of this evidence, we review the current evidence for the neuroadaptive mechanisms underlying benzodiazepine tolerance, including changes of (i) the GABA(A) receptor (subunit expression and receptor coupling), (ii) intracellular changes stemming from transcriptional and neurotrophic factors, (iii) ionotropic glutamate receptors, (iv) other neurotransmitters (serotonin, dopamine, and acetylcholine systems), and (v) the neurosteroid system. From the large variance in the studies, it appears that either different (simultaneous) tolerance mechanisms occur depending on the benzodiazepine effect, or that the tolerance-inducing mechanism depends on the activated GABA(A) receptor subtypes. Importantly, there is no convincing evidence that tolerance occurs with α subunit subtype-selective compounds acting at the benzodiazepine site.

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.

Effects of drugs on sleep

Many commonly prescribed medications and substances of abuse can have significant effects on sleep and wakefulness. Chronic use or abuse of certain drugs may lead to the development of substance-related sleep disorders. Primary sleep disorders, such as apnea, periodic movement disorders, and parasomnias, may be exacerbated by various drugs. This article summarizes the effects of widely used medications and recreational drugs on sleep.

Effects of drugs on sleep

Many commonly prescribed medications and substances of abuse can have significant effects on sleep and wakefulness. Chronic use or abuse of certain drugs may lead to the development of substance-related sleep disorders. Primary sleep disorders, such as apnea, periodic movement disorders, and parasomnias, may be exacerbated by various drugs. This article summarizes the effects of widely used medications and recreational drugs on sleep.

Current benzodiazepine issues

This article deals with some of the recent evidence bearing on the issues of the liability of benzodiazepines to lead to abuse, dependence, and adverse behavioral effects. Reviews of epidemiological, clinical and experimental literature indicated that the previous conclusion about abuse of these drugs still holds: the vast majority of the use of benzodiazepines is appropriate. Problems of nonmedical use arise nearly exclusively among people who abuse other drugs. Nevertheless, there are reasons for concern about patients who take benzodiazepines regularly for long periods of time. These drugs can produce physiological dependence when taken chronically, and although this does not appear to result in dose escalation or other evidence of "psychological dependence," physiological dependence can result in patient discomfort if drug use is abruptly discontinued. Also, physicians are currently prescribing shorter-acting benzodiazepines in preference to longer-acting benzodiazepines. The shorter-acting drugs can produce a more intense withdrawal syndrome following chronic administration. Furthermore, rates of use of benzodiazepines increase with age, and elderly patients are more likely than younger ones to take the drug chronically. The clearest adverse effect of benzodiazepines is impairment of memory. This, too, may be particular concern in older patients whose recall in the absence of drug is typically impaired relative to younger individuals, and who are more compromised following drug administration.

Comparison of the daytime sleep and performance effects of zolpidem versus triazolam

Fifty healthy male subjects were administered zolpidem (5, 10, or 20 mg), triazolam (0.5 mg) or placebo, then attempted to sleep in a non-sleep-conducive environment. Subjects were awakened at 90 min post-drug (near peak blood concentration for both drugs) and tested on several cognitive tasks, including Two Column Addition, Logical Reasoning, and a Simulated Escape Task. This was followed by a second, 3.5-h sleep period. Hypnotic efficacy of the 20 mg zolpidem (Z-20) dose was similar to that of the 0.5 mg triazolam (TRIAZ) dose, as indicated by comparably shortened sleep latencies and lengthened total sleep times. Though accuracy on most performance measures was not affected by either drug, a reduction in speed of responding on logical reasoning and addition tasks was evident for the TRIAZ group at 90 min post-drug (Ps less than 0.05). On the simulated escape task, only triazolam significantly increased the mean number of errors, and interfered with subsequent memory of the task. Thus, zolpidem had milder effects on performance than triazolam. However, 60% of the Z-20 subjects experienced mild, adverse physical reactions. Performance differences between somnogenically comparable doses of zolpidem and triazolam may be due to their differential affinities for the BZ1 and BZ2 receptor subtypes.

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

This study was undertaken to determine whether a single night's use of triazolam by normal healthy sleepers leads to withdrawal insomnia on the subsequent night, and whether there is a dose response relationship to this phenomenon. Thirty normal sleepers of both sexes were randomly assigned to three parallel treatment groups. All subjects were studied for five consecutive nights by means of pre- and post-sleep questionnaires and all night polysomnography. Multiple sleep latency tests were conducted on the days following the second, third, and fourth nights in the laboratory. All subjects received placebo capsules on the first, second, fourth, and fifth nights in the laboratory and either placebo, 0.25 mg triazolam or 0.5 mg triazolam according to their assigned group on the third night. Both doses of the drug increased subjective estimates of sleep duration, but no objective increase was found. Neither dose altered daytime measures of sleepiness. No changes were found in any of the sleep parameters on withdrawal of the 0.25 mg dose of triazolam. However, discontinuation of the 0.5 mg dose did lead to significant objective and subjective withdrawal effects. It was concluded that higher doses of triazolam could lead to withdrawal effects in normal sleepers even when this drug was used for only a single night.

Role of hypnotic drugs in general practice

General practice physicians commonly deal with patients who report experiencing insomnia. Advances in our understanding of insomnia should result in much more effective diagnosis and therapeutic intervention for insomnia patients at the primary care level. This presentation highlights the new knowledge of insomnia pertinent to general practice physicians and discusses the rational use of hypnotic medications in primary care.

Rebound insomnia: its determinants and significance

Rebound insomnia is a sleep disturbance that occurs on discontinuation of benzodiazepine hypnotic drugs. It has been reported in both patients and healthy normal subjects and is characterized by increased wakefulness above the person's baseline levels. This article reviews that available information regarding determinants, possible mechanisms, and clinical significance of rebound insomnia. It is concluded that rebound insomnia is a disturbance of one or two nights' duration that primarily follows discontinuation of short- to intermediate-acting benzodiazepines. It occurs at high doses of a given drug, beyond which no additional hypnotic efficacy is evident. There seem to be clear individual differences in the experience of rebound insomnia, but no prospective studies have established which differences predict rebound. It is likely to be avoided by initiating treatment with the lowest effective dose and tapering the dose upon discontinuation.

Administration of triazolam prior to recovery sleep: effects on sleep architecture, subsequent alertness and performance

The effects of triazolam (0.125, 0.25, and 0.5 mg) versus placebo on recovery sleep staging, subsequent alertness and psychomotor performance were evaluated in humans. Forty-five healthy male subjects were deprived of sleep for 24 h, then administered a single dose of triazolam or placebo using a double-blind procedure. Subjects then attempted to obtain recovery sleep under non-sleep-conducive conditions (sitting upright in a well-lit, crowded chamber) for the next 6 h, followed by 18 more hours of sleep deprivation. During all sleep deprivation periods subjects were tested bihourly on a performance assessment battery which included symbol digit modalities tests (SDMT), four-letter search (FLS), logical reasoning (LR), time estimation (TE), visual vigilance (VV), and short term memory (STM) tasks. Sleepiness levels were measured objectively with multiple sleep latency tests (MSLT) and subjectively with the Stanford Sleepiness Scale (SSS). Compared to placebo, all doses of triazolam resulted in increased amounts of stage 3-4 sleep, and the 0.5 mg dose significantly reduced awakenings (Ps less than 0.05). Although subjects receiving triazolam averaged 21-42 min more total sleep time (TST) than subjects receiving placebo, differences in TST were not statistically significant. Apparent triazolam-mediated benefits to sleep quality resulted in no obvious improvements in performance or alertness levels during subsequent sleep deprivation. It was concluded that the increases in stage 3-4 sleep amounts were most likely due to triazolam-mediated increases arousal thresholds, and the triazolam mediated changes in sleep parameters obtained in the present study were not indicative of substantial changes in the recuperative value of sleep.

Alprazolam: effects on sleep and withdrawal phenomena

Alprazolam was evaluated in chronic insomniacs in a 1-mg bedtime dose. The 16-night sleep laboratory protocol included four placebo-baseline nights followed by seven nights of drug administration and five placebo-withdrawal nights. On the first three drug nights (nights 5 to 7), the drug was highly effective in inducing and maintaining sleep with this short-term use. By the end of the one week of administration (nights 9 to 11), however, the drug had lost about 40% of its efficacy. During drug use, one subject reported some difficulty in controlling expression of inappropriate emotions when interacting with others, which suggested the presence of disinhibition. On the third night following drug termination, there was a significant increase in sleep difficulty above baseline levels (rebound insomnia). This worsening was of comparable magnitude to the peak improvement of sleep with drug administration. Thus, the clinical utility of alprazolam when administered to insomniac patients appears to be limited because of a relatively rapid development of tolerance and possible disinhibitory reactions during drug use and the occurrence of rebound insomnia following withdrawal.

Dose determinants of rebound insomnia

A polysomnographic assessment in healthy normal sleepers of possible dose relations for rebound insomnia was conducted. As an additional measure of rebound the study included a direct test of sleep/wake tendency during the night of drug discontinuation. Twelve, healthy men (21-30 years) each received placebo, 0.25 mg and 0.50 mg triazolam for 6 consecutive nights followed by a discontinuation night and 14 nights of recovery at home. The three conditions were presented, double-blind, in a latin square design. On night 6 of drug administration both doses increased total sleep time compared to placebo, but 0.50 mg did not improve sleep beyond 0.25 mg. On drug discontinuation (night 7) wake time over the 8 h recording and sleep latency after an experimental awakening (02.30 h) were increased with 0.50 mg compared to placebo and 0.25 mg. On these measures of rebound 0.25 mg did not differ from placebo. Thus rebound insomnia occurred only at a dose (0.50 mg) which produced no additional hypnotic efficacy in these normal sleepers. Whether tests of sleep/wake tendency make a useful measure of rebound insomnia needs further clarification.

Behavioral side effects of triazolam in psychiatric inpatients: report of five cases

Triazolam was administered to five psychiatric inpatients for a two-week period. This period was preceded by a one-week placebo baseline and followed by another week of placebo administration. All conditions were double blind. By the second week of active drug administration, psychopathology greatly intensified across all of the patients with the emergence of anxiety, memory impairment, confusion, paranoid ideation, and hallucinations. The drug-induced behavioral changes persisted during the initial withdrawal period, but then gradually subsided. Also following drug withdrawal, four patients showed a marked worsening of their sleeplessness for several nights.

Relative abuse liability of triazolam: experimental assessment in animals and humans

The abuse liability of a drug is a positive, interactive function of the reinforcing and adverse effects of the drug. The relative abuse liability of the hypnotic benzodiazepine, triazolam, has been controversial. This paper reviews animal and human studies bearing on its relative abuse liability, including data on pharmacological profile, reinforcing effects, liking, speed of onset, discriminative stimulus effects, subjective effects, physiological dependence, rebound and early morning insomnia, drug produced anxiety, lethality in overdose, psychomotor impairment, interactions with ethanol, anterograde amnesia, impaired awareness of drug effect, and other psychiatric and behavioral disturbances. It is concluded that the abuse liability of triazolam is less than that of the intermediate duration barbiturates such as pentobarbital. Although there are considerable data indicating similarities of triazolam to other benzodiazepines, there is also substantial speculation among clinical investigators and some limited data suggesting that the abuse liability of triazolam is greater than that of a variety of other benzodiazepines, and virtually no credible data or speculation that it is less. Further research will be necessary to clarify definitively the abuse liability of triazolam relative to other benzodiazepines.

Rebound insomnia and elimination half-life: assessment of individual subject response

Following abrupt withdrawal of five benzodiazepine hypnotics, the presence of rebound insomnia on individual subject nights was evaluated in comparison to a placebo group. During the first three nights of withdrawal, the frequency of occurrence of rebound insomnia for drugs with relatively rapid rates of elimination (triazolam, midazolam, and lormetazepam) was significantly higher than that for the placebo control group. In contrast, the frequency of withdrawal sleep difficulty for two slowly eliminated hypnotics (flurazepam and quazepam) was similar to that of the placebo control group during each of five successive three-night segments of a 15-night withdrawal period. These findings, based on individual subject-night data, confirm and extend previous reports using group mean values that demonstrate a frequent, immediate, and intense degree of rebound insomnia following abrupt withdrawal of relatively rapidly eliminated hypnotic drugs and an infrequent, delayed, and milder degree of sleep difficulty following withdrawal of slowly eliminated drugs.

Pharmacology and hypnotic efficacy of triazolam

Triazolam is a new triazolobenzodiazepine drug that is indicated for the treatment of insomnia. The usual adult dosage is 0.25 to 0.5 mg; for geriatric patients a dose of 0.125 to 0.25 mg is recommended. Triazolam is readily absorbed and quickly eliminated with a half-life of 2-5 hours, making it the shortest acting benzodiazepine available in the United States. Sleep laboratory and non-laboratory clinical trials found triazolam 0.25 and 0.5 mg effective in inducing and maintaining sleep. It remained effective in laboratory studies of up to one month duration and non-laboratory studies of up to six months duration when the drug was administered nightly. On discontinuation disturbed sleep for one or two nights was observed in some studies. Triazolam impairs performance for several hours after administration. However, unlike benzodiazepines with long-acting metabolites, triazolam is relatively free of daytime residual effects, which is attributable to its short half-life. Overall, triazolam is an effective and safe compound for the symptomatic treatment of insomnia complaints.

Triazolam as a hypnotic for geriatric patients. A double-blind cross-over comparison of nitrazepam and triazolam regarding effects on sleep and psychomotor performance

Triazolam 0.25 mg was compared with nitrazepam 5 mg as a hypnotic for 26 geriatric inpatients in a double-blind cross-over study. Sleep quantity and quality and psychomotor performance were studied. The sleep quantity and quality were similar for both drugs. There were no statistically significant differences between the two drugs in the psychomotor tests. The results are in contrast to results from other studies and might be explained by the composition of the patient material in the present study.

Brotizolam: a sleep laboratory evaluation

Brotizolam 0.25 mg was evaluated in a sleep laboratory study of 10 normal subjects. The study covered 10 consecutive nights and included 4 placebo-baseline nights, 3 nights on the drug and 3 placebo-withdrawal nights, which permitted assessment of initial drug effects, side effects and withdrawal phenomena, such as rebound insomnia. There was a significant increase in total sleep time with drug administration; the improvement in sleep occurred primarily in the first third of the night following the onset of sleep. During the day after nightly drug administration, the presence of rebound anxiety was suggested by an increase in reports of anxiety/tension as compared to baseline. Following drug withdrawal there was a significant increase in total wake time above baseline level, to 40% above baseline on the first and third nights of withdrawal.

Dose-response studies of lormetazepam: efficacy, side effects, and rebound insomnia

Lormetazepam, an investigational hypnotic, was evaluated for efficacy and withdrawal phenomena in doses of 0.5, 1.0, 1.5, and 2.0 mg in four separate sleep laboratory protocols, each including four placebo baseline nights, seven drug nights, and three placebo withdrawal nights. A moderate degree of efficacy was shown across the four doses, but this was quite variable. There was no dose-response effect for efficacy for either the first three or last three nights of this short-term administration period. In general, there was less efficacy on the later drug nights, indicating a potential for the development of tolerance over a relatively short period of time. Following drug withdrawal, there was a dose-related worsening of sleep above baseline levels (rebound insomnia). The peak degree of worsening of sleep following drug withdrawal was more than two times greater than the peak degree of improvement of sleep with drug administration.

Insomnia and other sleep disorders

In treating the symptomatology of patients who are chronically ill, it is likely that the physician will encounter a significant number of patients who have sleep disorders. This article has described an approach for the assessment, differential diagnosis, and clinical management of the most prevalent sleep disorders, which are often chronic in nature and have significant psychosocial or medical consequences for the patient and his or her family. We have emphasized the importance for the physician to complement his general medical and diagnostic skills by taking a careful sleep history from the patient (and, in some instances from the bed partner or caretakers). There is no justification for the physician to routinely request costly sleep laboratory hypnopolygraphic evaluations to screen patients with sleep disorders. However, in those instances where the sleep history is highly suggestive of sleep apnea, a sleep laboratory evaluation is indicated. By incorporating the use of the sleep history in the general evaluation of patients with sleep disorders, the physician is better able to develop rational pharmacologic and non-pharmacologic approaches to managing these patients, including the judicious use of medication as an adjunctive treatment.

Comparison of nitrazepam with triazolam in insomniac outpatients

The short-acting hypnotic, triazolam 0.5 mg, was compared in a 7-day double-blind study with the longer acting drug, nitrazepam 5 mg. Of the 60 patients enrolled, 29 in each drug treatment group completed the study and were evaluated. All significant differences found favoured triazolam. On the first night, triazolam was found to be significantly more effective than nitrazepam in inducing and maintaining sleep and in increasing its overall duration. The patients' subjective preference, reflecting the depth of sleep experienced and the effect of the medication, reached highly significant levels in favour of triazolam. Later in the study the differences between the drugs disappeared although the depth of sleep as judged in the study was better with triazolam.

Approaches in the evaluation of hypnotics: studies with triazolam

1 The evaluation of an hypnotic may be approached from the view that insomnia is a primary disease or the symptom of an underlying emotional or physical problem.

2 The two approaches have been used in the investigation of triazolam.

The use of short- and long-acting hypnotics in clinical medicine

1 Activity of short- and long-acting benzodiazepines is reviewed with reference to pharmacokinetics and residual sequelae, and to efficacy and adverse effects. 2 Some benzodiazepines may not lead to obvious effects on performance, such as nordiazepam and clobazam, and the persistence of residual sequelae may not relate obviously to elimination half-lives (as with diazepam and possibly flunitrazepam). However, benzodiazepines with mean half-lives less than 8 h may have residual sequelae, whereas hypnotics with mean half-lives greater than 16 h are likely to lead to impared performance and/or anxiolytic effects the next day. 3 Potassium chlorazepate 15 mg, with its long-acting metabolite nordiazepam, would seem to be the drug of choice for insomnia secondary to anxiety. For the insomniac without significant psychopathology, temazepam 10-20 mg, triazolam 0.125-0.25 mg and for occasional use, diazepam 5-10 mg, provide the initial approach. Flurazepam hydrochloride 15-30 mg, nitrazepam 5-10 mg and flunitrazepam 1 mg and above, have persistent residual effects and should be reserved for refractory patients, and for those in whom some impairment of performance the next day would be acceptable. 4 There is little or no evidence to suggest that the proper use of the short-acting hypnotics, triazolam and temazepam, leads to a worsening of sleep on withdrawal. However, some benzodiazepines may lead to disturbances of sleep and/or rebound insomnia, and nitrazepam and flunitrazepam may be implicated.

The efficacy of triazolam and chloral hydrate in geriatric insomniacs

A double-blind crossover study was performed to evaluate the efficacy of hypnotics in geriatric insomniacs. Twenty-seven patients with a mean age of 70 years (range 60-94 years) received each of five treatments on 5 consecutive nights. The treatment conditions, consisting of chloral hydrate 250 and 500 mg, triazolam 0.25 and 0.50 mg, and placebo, were administered using a Latin Square design. Subjective estimates of sleep were collected in the morning following each treatment night. The patients' global evaluation of effectiveness indicated that triazolam 0.25 mg and 0.50 mg improved sleep more than placebo, while chloral hydrate 250 and 500 mg were not better than placebo. Triazolam 0.50 mg was felt to be significantly better than either dose of chloral hydrate. In addition, triazolam 0.50 mg was found to significantly decrease the patients' estimates of their sleep latency. Patients estimated their total sleep time to be longer following the use of triazolam 0.25 mg as compared to choral hydrate 500 mg, and their estimates of the number of awakenings was significantly lower on triazolam 0.50 mg than it was on chloral hydrate 500 mg or placebo.

Studies on sleep and performance with a triazolo-1, 4-thienodiazepine (brotizolam)

1 Brotizolam, a triazolo-1,4-thienodiazepine, was studied in healthy young adults. Electroencephalographic sleep variables and subjective effects, and performance on a visuo-motor coordination task were measured. 2 In the sleep studies six males each ingested 0.2, 0.4 and 0.6 mg brotizolam overnight. All doses increased total sleep time, improved the sleep efficiency index, and reduced drowsy sleep and number of awakenings. Brotizolam 0.4 and 0.6 mg also reduced awake activity and increased stage 2 sleep. There was some evidence of a delay to the first REM period, but only 0.6 mg reduced the total duration of REM sleep. There were no changes in slow wave sleep. 3. In the performance studies six females each ingested 0.4 mg in the morning and 0.2, 0.4 and 0.6 mg brotizolam at night. After morning ingestion of 0.4 mg there was impaired performance from 0.5 to 5.5 h. There were no residual effects after 0.2 mg brotizolam, but with 0.4 mg there was a residual effect at 9.5 h, and 0.6 mg led to impairments up to 15.0 h after ingestion. 4 Brotizolam is a short-acting hypnotic. In doses around 0.2 mg it has useful hypnotic activity free of adverse effects on sleep and residual effects on performance. With 0.4 mg the hypnotic effect is enhanced with only minimal residual effects.

Chronic use of triazolam: the effects on the sleep patterns of insomniacs

The present study was designed to evaluate the effects of triazolam 0.5 mg on the sleep of insomniac patients when given for 3 weeks. The results showed that both acute and chronic triazolam administration are effective in decreasing sleep latency, increasing sleep duration, increasing sleep efficiency and decreasing total wake time without producing major effects on sleep staging. Sleep Stages 1 and 2 were significantly altered by drug treatment but in a positive direction. This change is primarily attributable to the significant decrease in sleep onset. Deep sleep and REM were not significantly changed during triazolam treatment nor was there any evidence of REM rebound after discontinuation of the medication. It was noted that some of the sleep parameters measured shifted toward baseline measures in the first night after triazolam treatment was terminated. However, the total recovery period recorded (7 days) showed the quality and quantity of sleep obtained to be improved over baseline measures. The recovery data compared favourably with those improvements noted during chronic administration of triazolam. It was also found that 3 weeks of triazolam 0.5 mg usage did not result in tolerance to its hypnotic properties. Thus, triazolam maintains its hypnotic effectiveness throughout 3 weeks of administration.

Activity of the hypnotics, flunitrazepam and triazolam, in man

1 Effects of flunitrazepam and triazolam (0.25 and 0.5 mg) on sleep and on performance were studied in six healthy adult males. Sleep was assessed by electroencephalography and analogue scales, and performance by a visuo-motor coordination task.

2 Over the same dose range triazolam had a more pronounced effect than flunitrazepam. Total sleep time was increased by 0.25 and 0.5 mg triazolam, and by 0.5 mg flunitrazepam. Both drugs decreased awake activity and drowsy sleep, though the effect of flunitrazepam was limited to the 0.5 mg dose and restricted to the first 6 h after sleep onset. There were no changes in slow wave sleep.

3 Latency to the first period of rapid eye movement (REM) sleep was increased with 0.5 mg triazolam, and when doses were combined (0.25-0.5 mg) the latencies with both drugs were increased. Both doses of triazolam reduced the duration and percentage of REM sleep during the early part of the night, though the whole night duration of REM sleep was not changed.

4 After the morning ingestion of 0.25 mg flunitrazepam performance was impaired for 2.0 h, but there were no residual effects when 0.25 or 0.5 mg were taken at night. With the morning ingestion of 0.25 mg triazolam performance was impaired from 0.5 to at least 5.0 h after ingestion. There were no residual effects with 0.25 mg overnight, but with 0.5 mg triazolam there was an effect on performance 10 h after ingestion with recovery within 1.5 h (11.5 h of ingestion).

5 Triazolam (0.25 mg) and 0.5 mg flunitrazepam provide useful hypnotic activity when impaired performance the next day is to be avoided. The activity of 0.5 mg triazolam is accompanied by only limited residual sequelae compared with some other benzodiazepines of comparable efficacy, and so may prove to be useful when a more powerful effect is required.

The effects of flurazepam, lorazepam, and triazolam on sleep and memory

This study evaluated the effects of flurazepam 30 mg, lorazepam 4 mg, triazolam 0.5 mg, and placebo upon sleep and memory in eleven normal male subjects continuously monitored for nighttime EEG, EOG, and EMG recording. Subjects received each drug or placebo for two consecutive nights per week for 4 weeks in a repeated measures, double-blind, Latin Square design. Three hours post-administration, subjects were awakened and presented with a series of tasks. Recall was assessed immediately following task presentation and after the final morning awakening. The results showed that every drug significantly decreased stage 1, increased stage 2, and produced no change in stage 3--4 sleep in comparison to placebo. Only lorazepam significantly decreased REM percent. Post-drug recall was significantly decreased in comparison to placebo at night and was further decreased in the morning. Morning recall was significantly poorer when the return to sleep was 2.5 min or less than when the return to sleep was greater than 5 min following the nighttime awakening in all drug conditions. These results indicate that 1. failure of memory consolidation rather than failure of retrieval is the most likely explanation for the morning memory loss and 2. hypnotic drug properties, measured by latency to fall back asleep, affect memory consolidation.

Clinical evaluation of hypnotic drugs: contributions from sleep laboratory studies

The most thorough and clinically relevant approach to hypnotic drug evaluation is one that balances the strengths and weaknesses of clinical trials and sleep laboratory evaluations. Advantages of clinical trials include the ability to evaluate large numbers of subjects and specific target groups and to thoroughly assess and quantify a drug's side effects, whereas sleep laboratory studies are very limited in all of these areas. Sleep laboratory studies however provide a rigorous, precise, and comprehensive profile of a drug's activity since there is more control over experimental variables and measurements are objective as well as continuous throughout the night. These benefits offset the shortcomings of clinical trials, which include a lack of objective measurements, less control over experimental variables, failure to evaluate a drug's effectiveness with continued use, and inattention to drug interaction and withdrawal effect. Several basic principles derived from sleep laboratory findings have been incorporated into both the clinical trials and sleep laboratory evaluations recommended in the new FDA Guidelines for the Clinical Evaluation of Hypnotic Drugs. These principles include provision for adequate baseline and withdrawal periods, use of multiple consecutive drug nights to assess a drug's effectiveness with continued use, and inclusion of an adequate washout period when a cross-over design is used. The guidelines do not emphasize either clinical trials or sleep laboratory studies at the expense of each other, but rather stress their complementary utilization.

Rebound insomnia: a new clinical syndrome

Rebound insomnia followed the withdrawal of three benzodiazepine hypnotic drugs, each of which had been administered in a single nightly dose for only short-term periods. The intense worsening of sleep is attributed to the short duration of the action of these drugs. A hypothesis involving benzodiazepine receptors in the brain is proposed in which there is a delay or lag in replacement of endogenous benzodiazepine-like molecules after the abrupt withdrawal of exogenous drugs.

Multiclinic double-blind comparison of triazolam and flurazepam for seven nights in outpatients with insomnia

In this two-clinic seven-day double-blind study, 0.5 mg triazolam (Halcion) was compared to flurazepam (Dalmane) in the treatment of insomnia. Two clinical investigators completed 118 outpatients, 61 on triazolam and 57 on flurazepam. Five patients, four on triazolam and one on flurazepam, discontinued because of side effects; and three patients, one on triazolam and two on flurazepam, discontinued because of ineffectiveness of the medication. Analysis of pooled data for the 110 evaluable patients showed that 0.5 mg triazolam was significantly better than 30 mg flurazepam on the following parameters: (1) how much the medication helped the patients sleep, (2) onset of sleep, (3) duration of sleep, (4) evaluation of duration of sleep, and (5) feeling of restfulness in the morning. The trend for all other parameters favored triazolam treatment, but the values did not reach statistical significance. Side effects were similar in both groups, with drowsiness being reported most frequently. No change in efficacy indicating tolerance development during the seven days of drug administration was observed in either group.