Activity of the hypnotics, flunitrazepam and triazolam, in man

Perceived Quality of Sleep and Levels of Daytime Sleepiness among Elderly Women Caregivers of Alzheimer's Disease Patients

Perceived quality of nocturnal sleep and levels of daytime sleepiness were measured using the S3Q and Nicholson Stone scales (sleep quality) and the Stanford Sleepiness scale (sleepiness). A sample of 15 elderly (mean age 72 [±8.9] years) women who were primary caregivers and who resided in the same household as the patient participated in the study for 3 consecutive days a week over a 9-week period. Results showed caregivers had "fair" sleep quality and a "moderate" level of daytime sleepiness.

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

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

Benzodiazepine effects on human sleep EEG spectra: a comparison of triazolam and flunitrazepam

The effects of 0.5 mg triazolam (TRI) and 4 mg flunitrazepam (FNZ) on the sleep electroencephalogram (EEG) were studied in eleven (six for TRI, and five for FNZ) healthy young male subjects. C3 EEG channel data of one baseline night, three drug nights and two withdrawal nights were recorded and their analyzed using a fast Fourier transformation (FFT) method. Changes in the 0.5 Hz to 40 Hz power spectrum showed that: 1) both TRI and FNZ increased higher frequency activity and reduced lower frequency activity on the drug nights; 2) on drug nights, NREM sigma frequency power was more strongly enhanced by TRI than FNZ, while the beta power of both NREM and REM was more strongly enhanced by FNZ than TRI; 3) NREM alpha power increased on the second night of withdrawal from both TRI and FNZ; 4) the power spectra for both NREM and REM sleep returned to baseline levels by the fourth night of withdrawal from either TRI or FNZ. These findings suggest that 0.5 mg TRI and 4 mg FNZ have both common and differing pharmacological effects on the central nervous system. Such differences could be caused by differences in the dose, half-life or systemic distribution of these two drugs.

Promoting sleep in shiftworkers and intercontinental travelers

A number of techniques and treatments can be used to alleviate the sleep disturbance associated with both shiftwork and transmeridian travel. Optimization of the sleeping environment and avoidance of substances such as caffeine and alcohol before sleep are the best initial approach. Timing sleep to coincide with some of the normal sleep period where possible will improve sleep quality in shiftworkers. Similarly, following transmeridian flight, restricting sleep to the nocturnal period in the new time zone will assist adaptation. Hypnotic drugs may be of benefit to alleviate sleep disturbance experienced by shiftworkers or transmeridian travelers. Selection of the most appropriate medication must take into account required duration of action and possible residual effects of the drug on alertness. Hypnotics may be useful, particularly in middle-aged individuals who already have disturbed sleep, on those occasions when poor sleep is anticipated, for example following an eastward flight or after the initial change to night duty. Over-the-counter preparations should be avoided whenever possible unless it is known that they are not associated with residual sequelae.

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.

Triazolam pharmacokinetics after intravenous, oral, and sublingual administration

This study was designed to evaluate the relative and absolute bioavailability of triazolam, 0.25 mg, after the administration of the marketed oral tablet and a sublingual prototype wafer; an intravenous dose was used as a reference. Twelve men were evaluated in a three-way crossover study; study days were separated by 1 week. A single dose was administered to each subject at approximately 8 a.m.; serial blood samples were obtained for the determination of triazolam concentration. The fraction absorbed relative to intravenous was 20% higher in the sublingual than in the oral treatment (p = 0.0128); the difference between treatments was greatest in the first 2 hours as indicated by the area under the curve from 0 to 2 hours (p < 0.05). The extraction ratio ranged from 0.05 to 0.25, and the predicted availability after oral administration was 86% with a range of 75 to 95%. In contrast, the observed mean absolute availability was 44% (oral) and 53% (sublingual). A potential explanation for this discrepancy between predicted and observed bioavailability is that after oral administration, a fraction of triazolam may be metabolized by cytochrome P450IIIA4 in the gut wall, with a separate fraction subject to first-pass metabolism in the liver. Although this study was not designed to identify sites of triazolam metabolism, the proposed explanation is consistent with the occurrence of P450IIIA4 in the stomach, small intestine, and liver. Doses administered sublingually avoid first-pass metabolism, producing earlier and higher peak concentrations than do doses administered orally.

Using triazolam to reduce dental anxiety

Triazolam, commonly prescribed to treat insomnia, also can be used to reduce dental anxiety. Despite controversial reports in the lay press, triazolam can be used safely at low doses for short periods. The authors review research concerning the drug's safety and discuss its use in dentistry.

Oral benzodiazepines and conscious sedation: A review

A large number of benzodiazepines have been studied for use as sedatives and for their anxiolytic potential as premedicants for outpatient surgery. Potent, new, orally-administered drugs with short half-lives, rapid onset, and minimal residual effects have been developed. Dose-dependent amnesia is also produced by some of these agents. Advances in understanding receptor physiology have shed light on specific pharmacologic activities and aided the discovery of benzodiazepine antagonists with antidote properties. While these drugs have relatively low toxicity, dose-related oversedation remains a risk in susceptible patients, especially when combined with other sedatives.

Study of the potential reversal of triazolam memory and cognitive deficits by RU 41 656 in healthy subjects

The potential antagonism of a single oral dose of RU 41 656 (10 mg) on the memory and attention disturbances induced by oral administration of triazolam (0.25 mg) have been investigated in a 3-period, placebo controlled, double blind, cross-over study involving 12 healthy young volunteers. The effects of the compounds were evaluated by objective tests (Buschke selective reminding test, CFF, simple reaction time, tapping, arithmetical calculation) and subjective measurements (visual analogue scale, side effects questionnaire). Measurements were taken before treatment and 2, 4 and 7 h after RU 41 656 intake. Triazolam caused anterograde amnesia as already described with other benzodiazepine with few sedative effects at this dosage. Under the experimental conditions of the trial, RU 41 656 failed to counteract the memory deficits induced by triazolam.

A guide to benzodiazepine selection. Part I: Pharmacological aspects

Since absorption rates, volumes of distribution and elimination rates differ greatly among the benzodiazepine derivatives, each benzodiazepine has a unique plasma concentration curve. Although the time to peak plasma levels provides a rough guide, it is not equivalent to the time to clinical onset of effect. Two half-lives can be described: the alpha half-life, the rate of decline in plasma concentrations due to the process of drug redistribution from the central to the peripheral compartment, and the beta half-life, the rate of decline due to the process of drug elimination due to metabolism. The frequent classification of benzodiazepines into long, intermediate, and short-"acting" categories based on their terminal beta half-lives is unfounded; the duration of action is much more dependent on the alpha half-life. Benzodiazepines with short beta half-lives are commonly thought to be preferable because they accumulate less. However, with repeated use, sedation and cognitive neuromotor impairment usually diminish progressively despite stable or even rising benzodiazepine plasma concentrations, whereas anxiolytic effects generally persist over time.

Daytime wakefulness following a bedtime oral dose of zolpidem 20 mg, flunitrazepam 2 mg and placebo

1. The effects of zolpidem 20 mg, flunitrazepam 2 mg and placebo, administered at bed time, were studied in 12 healthy young male volunteers. 2. The assessments included, at awakening, subjective ratings of overnight sleep, cognitive function, psychomotor performance (digit symbol substitution, choice reaction time, flicker fusion threshold), subjective ratings of alertness, and plasma assay of residual drug concentration. Daytime sleep propensity during the day after dosing was evaluated with the multiple sleep latency test. 3. Compared with placebo, both active drugs improved subjective assessment of the ease of getting to sleep. At awakening, under flunitrazepam treatment, the reduction of performance, on memory and psychomotor tests, paralleled an increased subjective rating of sleepiness, but zolpidem treatment left subjects unimpaired compared with placebo. Similarly, daytime sleep propensity was enhanced throughout the following day under flunitrazepam treatment, but not under zolpidem treatment. Plasma assay for residual drug concentration at awakening found significant amounts of flunitrazepam and marginal amounts of zolpidem. 4. Results indicate that zolpidem 20 mg is devoid of residual effects in a range of tasks that were sensitive enough to demonstrate a prolonged wakefulness impairment following flunitrzepam 2 mg in healthy volunteers.

[Effects of zopiclone on sleep, daytime somnolence and nocturnal and daytime performance in healthy volunteers]

Ten healthy volunteers, aged 20 to 39, underwent 2 adaptation nights and 3 sessions of 2 consecutive experimental nights and days at 1 week intervals. In the 3 sessions, subjects received under double blind conditions either Zopiclone 3.75 mg or 7.5 mg or placebo, according to a latin-square design. On nights 1 and 2 of each session, subjects were continuously polygraphically monitored, except for a 45 min provoked wake episode 135 min after sleep onset on night 2. Sleep continuity and architecture were evaluated during night 1, degree of daytime somnolence during day 1 and residual effects during night 2 (0 h 00) and day 2 (8 h 00 and 12 h 00). Sleep continuity was not modified, except for a reduction of the number of night awakenings. NREM sleep stage 1 was reduced and stage 2 was increased (in duration but not in percentage) with Zopiclone 3.75 and 7.5 mg. NREM sleep stages 3 and 4 were increased with Zopiclone 3.75 mg only. REM sleep was reduced (in percentage only) with Zopiclone 3.75 and 7.5 mg. Daytime somnolence varied according to the time but not with the 3 different conditions. One performance test only (choice reaction time test) showed a significant impairment at 0 h 00 with Zopiclone 7.5 mg. From a subjective point of view, sleep quality was improved and night time awakening was reduced with Zopiclone 7.5 mg.

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.

A comparison of triazolam and diazepam as premedication agents for minor gynaecological surgery

Triazolam 0.25 mg, diazepam 10 mg and placebo were compared in a randomized double-blind trial of oral premedication in 90 patients undergoing minor gynaecological surgery. Both triazolam and diazepam produced a significant sedative effect as measured by patient self assessment linear analogue scales but only diazepam was more anxiolytic than placebo. Psychomotor performance assessed by the letter-search test at 3 and 6 hours after awakening showed a decrement in performance in patients receiving triazolam at 3 hours compared with the two other groups. Triazolam was shown to have a pronounced amnesic effect and whilst it might be used for premedication, its lack of anxiolysis coupled with a significant impairment of psychomotor performance at 3 hours after awakening, render the drug unsuitable for premedication in the short stay patient.

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.

Effects of diazepam and triazolam on auditory and visual thresholds and reaction times in the baboon

Adult male baboons were trained on a psychophysical procedure that measured detection thresholds and reaction times for pure tone and white light stimuli. Intramuscular injections of diazepam or triazolam were given 30 min before session onset; stimulus intensity was randomly varied from trial to trial, and four to five estimates of sensory thresholds and reaction times were obtained throughout each session. Diazepam produced dose-related elevations of both auditory and visual thresholds and reaction times. Effects of a single high dose of diazepam were apparent 4-5 days after administration. Triazolam was approximately 100 times more potent than diazepam in elevating reaction times and visual thresholds, but did not elevate auditory thresholds. There were no residual effects of triazolam on the day after dosing. These results suggest that diazepam and triazolam produce qualitatively similar effects on basic psychophysical function, but that they can be differentiated on the basis of sensory modality changes and post-drug recovery time.

Issues in the diagnosis and treatment of insomnia

Most people attribute a restorative function to sleep. This is because experimental or clinical sleep disturbance is usually followed by annoying symptoms of fatigue and sleepiness the following day. Can these daytime changes be documented objectively? In the past several years, the Multiple Sleep Latency Test (MSLT) has been developed and validated as an objective quantitative measure of sleepiness. Multiple assessments of sleep latency yield a profile of sleepiness across the day. This profile changes in the predicted direction with acute total and partial sleep deprivation, chronic sleep deprivation, sleep satiation, and in comparisons between hypersomnia patients and controls. Sleep and wakefulness are complementary phases in the daily cycle of human existence. Adequacy of sleep and energetic wakefulness next day are interacting phases in this cycle. Insomnia can be seen as a perception of disturbed sleep with daytime consequences, but is essentially also a symptom. This paper reviews a number of issues in the diagnosis and treatment of insomnia. The dimensions, daytime consequences and longitudinal aspects of insomnia are considered. Most investigations to date have been geared towards the problem of chronic insomnia and yet we are all likely to suffer from transient insomnia at some point. Psychiatric and psychophysiological disorders have been shown to be the most frequent causes of disorders of initiating and maintaining sleep. Moreover, there is an apparent disparity between subjective and objective sleep parameters with, for example, objectively disturbed sleep in noncomplaining subjects. The criteria of hypnotic efficacy and the effects of triazolam and flurazepam on sleep and daytime alertness have been investigated in normals, chronic insomniacs and the elderly. In general, chronic insomniacs showed all degrees of daytime alertness regardless of nocturnal sleep parameters. About one-third could be classified as fully alert all day long in spite of their complaints. The effect of flurazepam and triazolam on sleep (improvement) was essentially the same. Daytime effects were most closely related to half-life. The long-acting benzodiazepine, flurazepam, impaired daytime alertness although nocturnal sleep was improved. Triazolam improved not only nighttime sleep but also daytime alertness.

Flunitrazepam: acute benefit-risk assessment in general practice

A methodology is described which is practical in assessing the benefit-risk ratio of a single new drug prior to marketing. Flunitrazepam at doses of 0.5 mg, 1.0 mg (and 2 mg) nocte in 2,435 patients is shown to be effective in 78% of patients and the acute risk, predictable and low, irrespective of age or dose. One may conclude that the acute benefit-risk ratio is acceptable with respect to the class of drug and indication for which flunitrazepam is prescribed.

New drug evaluations. Triazolam

Triazolam is a sedative/hypnotic triazolobenzodiazepine, structurally related to alprazolam. Recently, it has been approved for the short-term management of insomnia characterized by difficulty in falling asleep, frequent nocturnal awakenings, and/or early morning awakenings. Triazolam is metabolized with a half-life of 1.5-5.0 hours. Its one active metabolite, which appears in low concentrations and is inactivated rapidly, is not thought to contribute to its pharmacologic activity. Triazolam has been shown to decrease sleep latency and the number of nocturnal awakenings while increasing total sleep time in patients with insomnia. Sleep electroencephalogram studies show that triazolam has no effect on delta-sleep (Stages 3 and 4) and has variable effects on rapid-eye-movement sleep. Nighttime administration of triazolam increases daytime alertness in insomniacs and improves or has no effect on performance. The reported side effects are similar to those of other benzodiazepines and include drowsiness, dizziness, and dry mouth. The recommended dosage of triazolam is 0.25-0.5 mg hs. A reduced initial dose of 0.125 mg should be used in geriatric patients.

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.

Effect of the benzodiazepine antagonist Ro 15-1788 on flunitrazepam-induced sleep changes

1 The modifications of human sleep induced by benzodiazepines, and particularly by flunitrazepam, are complex. Stage 4 and paradoxical sleep are both decreased; however, these two effects have a different evolution during and after single or short-term drug administration. 2 The benzodiazepine antagonist Ro 15-1788 also tends to depress stage 4, but with immediate recovery in the post-drug night, and does not modify paradoxical sleep. 3 In combined administration, this drug totally reverses the hypnogenic effect of flunitrazepam, as well as its effect on paradoxical sleep but not the decrease of slow wave sleep. 4 Some of the benzodiazepine-induced alterations of sleep may be related to receptors different from central benzodiazepine receptors, or to mechanisms not directly connected to this type of receptors.

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.

Residual and acute effects of flurazepam and triazolam in normal subjects

Residual and acute effects of flurazepam and triazolam were studied in two double-blind, crossover, placebo controlled, single-dose experiments. Psychological and physiological effects were determined 10 h after night administration (flurazepam 30 mg and triazolam 0.5 mg), and for 6 h after morning ingestion (flurazepam 15 mg and triazolam 0.25 mg). Both drugs produced similar "hangover" effects, impairing motor performance and increasing sleepiness on the following morning. After morning administration pronounced sedative effects were found with triazolam, while flurazepam effects were mild and hard to distinguish from placebo. The clinical relevance of these findings is discussed, suggesting that these drugs may be conceived as belonging to two different types of hypnotic agents.

Midazolam and triazolam in out-patients: a double-blind comparison of hypnotic efficacy

The hypnotic efficacy and the effect on the condition after morning awakening of midazolam 15 mg and of triazolam 0.5 mg were studied in a multicentre, double-blind cross-over study in 198 out-patients with sleeping difficulties of various origin. The subjects received each drug for two consecutive nights, and completed a questionnaire each day on awakening. Both midazolam and triazolam significantly shortened the sleep-onset latency, reduced the number of awakenings, and increased the total sleep time. The state on awakening was also significantly improved after both compounds for several self-rated items. There was a difference only with regard to the patients' feeling of being under drug influence, which was reported as being significantly more marked after triazolam. In conclusion, both compounds were effective and well tolerated in the doses used, only a few side-effects being reported.

Efficacy and tolerance: comparative studies with brotizolam and flunitrazepam

Efficacy of and tolerance to 0.25 mg brotizolam and 2.0 mg flunitrazepam were compared over a period of 6 days in ambulatory patients complaining of sleep disturbance. The study was double-blind and randomised with a parallel group design. Both drugs improved sleep. More patients assessed sleep latency as shorter during the first night of ingestion with flunitrazepam than with brotizolam, but assessments were comparable over the next 5 days. The number of patients who considered that the frequency of nocturnal awakenings was less did not differ significantly between drugs. Tolerance to brotizolam (0.25 mg) was assessed more favourably than with flunitrazepam (2.0 mg). The study suggests that brotizolam (0.25 mg) is indicated for patients who have difficulty in falling asleep and staying asleep, and who must preserve their alertness during the early part of the next day. Flunitrazepam (2.0 mg) is equally effective, but at this dose there is a higher incidence of adverse effects.

A placebo-controlled, dose-ranging study comparing 0.5 mg, 1 mg and 2 mg flunitrazepam in out-patients

A placebo-controlled, dose-ranging study was carried out in 18 patients, aged under 65 years, with sleep disturbance to compare the hypnotic effects of 0.5 mg, 1 mg and 2 mg flunitrazepam and placebo. Patients received each treatment in random order for 7 days. Assessments by both doctor and patients were made on entry and at the end of each treatment period. The results showed that the 1 mg flunitrazepam dose was optimal with respect to speed of action, duration of action, quality of sleep and lack of residual clinical sequelae.

Comparative pharmacokinetics of brotizolam and triazolam in healthy subjects

Pharmacokinetics of oral brotizolam (0.50 mg) and triazolam (0.50 mg) were studied in healthy young volunteers. The plasma concentration profile of brotizolam can be described as a one compartmental open model with first-order absorption. The absorption of triazolam was less regular and in half of the subjects was not consistent with first-order kinetics. Inter-individual variability in absorption rate (peak times) was larger for brotizolam. Mean peak times were 1.1 +/- 1.0 h for brotizolam and 1.2 +/- 0.5 h for triazolam. Mean peak concentrations were 7.3 +/- 3.1 ng/ml and 5.0 +/- 3.9 ng/ml respectively. The elimination half-life of brotizolam was twice that of triazolam with mean values of 5.0 +/- 1.1 h and 2.6 +/- 0.7 h respectively. There was no correlation between the half-lives of the two drugs. Protein unbound fraction was similar for triazolam and brotizolam with mean values of 9.9 +/- 1.5% and 8.4 +/- 0.7% respectively.

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.

Residual effects of repeated doses of 0.5 and 1 mg flunitrazepam

9 normal subjects were tested on a large battery of tests the morning after a hypnotic dose of flunitrazepam (0.5 mg and 1 mg) and a placebo. Each drug was given for 8 nights and assessments were made 10 and 13 h later on days 1, 4 and 8. Self-ratings of sleep were made every morning. The tests comprised mood and bodily symptom self-ratings, taping rate, visual reaction time, symbol copying and substitution tests, critical flicker fusion threshold, digit span and cancellation test. The EEG was recorded under eyes open and eyes closed conditions and analysed using broad waveband filters. Subjectively, the 0.5 mg dose was associated with increased alertness, contentment and calmness, the 1 mg dose with minimal decrease in alertness and contentment. Sleep onset was accelerated by flunitrazepam initially but effects on quality of sleep were not major due to subject selection. The 1 mg dose occasionally impaired performance on tapping, symbol copying and substitution and critical flicker fusion. The 0.5 mg dose marginally impaired symbol substitution and improved symbol copying. The EEG showed definite dose-related effects which tended to increase over the 8 nights of ingestion of the drug. It is concluded that whereas the 1 mg dose may sometimes be associated with definite residual effects the next day, the 0.5 mg dose possesses positive qualities in producing useful subjective effects the next day without appreciable impairment of psychological performance.

Effects of triazolam (0.5 mg) on sleep, performance, memory, and arousal threshold

The effects of a short-acting benzodiazepine hypnotic, triazolam (0.5 mg), on sleep, performance, and arousal threshold were assessed in 20 male poor sleepers (age 21 +/- 2.37 years). Following in a laboratory screening night, all subjects received placebo for 3 nights (single-blind), ten received triazolam and ten placebo for 6 nights (double-blind), and all received placebo on 2 withdrawal nights (single-blind). All effects described below were statistically significant. Triazolam reduced sleep latency and increased total sleep time and sleep efficiency. Percent Stage 2 was increased and percent Stage 4 was reduced during treatment. Morning performance, measured 8.25 h post-drug, showed no decrements. Acute effects were assessed on treatment night 6 during arousals from sleep at 1.5, 3, and 5 h post-administration: performance was impaired in triazolam subjects on the Wilkinson 4-Choice Reaction Time Test, Digit Symbol Substitution Test, Williams Word Memory Test, and Card Sorting Task. In the morning following treatment night 6, long-term memory was tested using a recognition task requiring subjects to identify words presented during night-time test batteries: triazolam subjects correctly identified fewer target words. Triazolam administration produced anterograde amnesic effects. However, in a Paired Associates Test learned prior to drug ingestion on the previous evening, triazolam did not impair morning recall of word pairs. Threshold for arousal from slow wave sleep was elevated during treatment, and triazolam subjects did not show increased sensitivity to the arousing tone over nights as did placebo subjects.

Sedative-hypnotics and human performance

In 52 studies, performance data were obtained the next day following bedtime ingestion of a sedative-hypnotic or a placebo. Only eight of these studies used insomniac patients. Most studies used young adult males. Benzodiazepine hypnotics were most frequently administered and psychomotor performance was most often measured. Little consistent data are available on cognitive functioning and more complex behavior. Drug-related improvement in performance was not found, and, in comparing active drug to placebo, it is clear that all hypnotics, at some doses, produce decrements in performance the next day. Higher doses consistently showed a decrement, and this decrement was usually persistent over the entire day. Although long-acting drugs generally showed more performance decrement, half-life data were not consistent.

Triazolam (Halcion) versus flunitrazepam (Rohypnol) against midwinter insomnia in Northern Norway

In a double-blind, cross-over trial, triazolam (0.25 mg) was tested against flunitrazepam (1 mg) in the typical midwinter insomnia which is often seen among otherwise healthy people in Northern Norway. Each drug was given for five nights, in random order, with a five-night placebo period between the active drugs (providing for a single blind comparison with placebo). A total of 2 outpatients started the trial; 19 completed. There were highly significant differences between each active drug and placebo on the subjectively scored variables sleep latency, duration of sleep, and total evaluation of sleep, and also significant differences for feeling in the morning, number of awakenings, and quality of sleep; all differences were in favour of the active drugs. Generally, the sleep variables were rated on the same level in the placebo period as they were for the last five nights prior to the trial. There were no significant differences between triazolam and flunitrazepam on any variable. However, eight patients stated a preference for triazolam and eight for flunitrazepam. These two groups of patients did not differ significantly with regard to sex, age, previous use of hypnotics, or severity of insomnia. Only three patients complained about side effects. Notably, the feeling of being alert and refreshed in the morning was significantly superior in the active drug periods as against the placebo period. It is concluded that both active drugs were highly effective, with a minimum of side effects, in this type of insomnia and with the relatively low dosage used.

Triazolam: a review of its pharmacological properties and therapeutic efficacy in patients with insomnia

Triazolam is a triazolobenzodiazepine with hypnotic properties, advocated for use in acute or chronic insomnia, situational insomnia in hospitalised patients, and insomnia associated with other disease states. As triazolam has a relatively short half-life of about 2 to 3 hours in healthy subjects and has only 1 short acting active metabolite, alpha-hydroxytriazolam, it would seem more suitable as an hypnotic than longer acting drugs such as flurazepam, nitrazepam or flunitrazepam, particularly when residual sedative effects on the day after ingestion are undesirable. Thus, with usual hypnotic doses of triazolam (0.25 or 0.5 mg) impairment of psychomotor and cognitive function is generally not carried over into the day after ingestion, although at doses of 1 mg or greater, residual effects may appear. In short term comparative studies triazolam was clearly superior to a placebo, and was at lest as effective as flurazepam, or other benzodiazepines such as nitrazepam or diazepam, in hastening sleep onset, reducing nocturnal awakenings, and increasing sleep duration. In other studies it was often superior to chloral hydrate, methyprylone or quinalbarbitone (secobarbital). In a small number of patients with chronic insomnia receiving extended treatment with triazolam in a clinical setting or in some sleep laboratory studies, no evidence of tolerance occurred; however, some evidence of reduced effect with repeated administration has been reported in one sleep laboratory study. Thus, a definitive statement about the likelihood of tolerance occurring on repeated administration is difficult to make at this time.

Effect of a short-acting benzodiazepine on brain electrical activity during sleep

The effects of the short-acting benzodiazepine, triazolam, on EEG activity during sleep were assessed in poor sleepers. Twenty male subjects, mean age 21 +/- 2.37 years, participated. A screening night preceded 3 placebo nights, 6 treatment nights, and 2 placebo-withdrawal nights. During treatment, 10 subjects received triazolam (0.5 mg) and 10 received placebo. The treatment condition was double-blind. In addition to rate/min spindle count and number of delta half-waves/min, the auditory evoked response (AEP) was obtained on the last placebo baseline and the fifth drug night. Subjects receiving triazolam showed a significant increase in sleep spindles and a significant decrease in delta count during drug administration. Both values returned to baseline on the first withdrawal night. The AEP peak-to-trough amplitude was also significantly reduced during sleep by triazolam, but, as the time since drug ingestion increased, the amplitude of the AEP also increased. There was no difference in AEP amplitude between the two groups 5 h post-drug ingestion.

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.

Efficacy of some benzodiazepines for day-time sleep

1 Effects of flunitrazepam (0.25-0.50 mg) and the 1,4-triazolodiazepines, triazolam (0.25-0.50 mg) and brotizolam (0.3-0.6 mg), on day time sleep were studied by electroencephalography. 2 Flunitrazepam (0.25-0.50 mg) and triazolam (0.25-0.50 mg) reduced awake activity (P < 0.05) and improved the sleep efficiency index (P < 0.05). The higher dose of each drug increased total sleep time (P < 0.05 and < 0.01 respectively) and duration of stage 2 sleep (P < 0.01), and also delayed the first REM period (P < 0.05 and < 0.01 respectively). 3 Brotizolam (0.6 mg) markedly increased total sleep time (P < 0.001) and the sleep efficiency index (P < 0.01), and prolonged stages 2 (P < 0.01 and slow wave (P < 0.01) sleep. Over the dose range 0.3-0.6 mg, the latency to stage 3 sleep was shortened (P < 0.05), and that to the first REM period lengthened (P < 0.05). 4 All three drugs improved day time sleep. However the present observations and data from previous studies suggest that flunitrazepam (0.25-0.50 mg) may be particularly appropriate for sleep at unusual times.

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.