Pharmacology and hypnotic efficacy of triazolam

Insomnia in General Practice

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

Semi-micro column HPLC of triazolam in rat plasma and brain microdialysate and its application to drug interaction study with itraconazole

Semi-micro column high-performance liquid chromatographic method with ultraviolet detection for the determination of triazolam (TZ) in rat plasma and brain microdialysate is described. The separation was achieved on a 250 x 1.5 mm, i.d. C(18) column and the column effluent was monitored at 222 nm. The detection limits at a signal-to-noise ratio of 3 obtained using spiked plasma and artificial cerebrospinal fluid were 2.1 and 0.7 ng/ml, respectively. The method was applied to drug-drug interaction study of TZ with itraconazole (ITZ). The peak concentration (C(max)) and the area under the curve (AUC) of TZ in brain microdialysate after simultaneous administration of TZ (2.5 mg/kg, intravenously (i.v.)) and ITZ (25 mg/kg, p.o.) to rats increased 3.4-folds (P<0.001) and 2.9-folds (P<0.001), respectively, compared to those of TZ alone. Also, the AUC of TZ in plasma increased 2.6-folds and remarkable delay in its elimination half-life (t(1/2)) was observed. The concentrations of TZ in brain microdialysate and plasma were also measured after single administration of TZ (2.5 mg/kg, i.v.) to rats pretreated with daily administration of ITZ (25 mg/kg, p.o.) once a day for a week. There was no significant difference in TZ's C(max) in both ITZ treatments (P>0.2) however its t(1/2) after the daily pretreatment with ITZ was significantly increased (P<0.05). In plasma, the AUC of TZ after daily pretreatment of ITZ was lower than the single combined treatment, but significantly different from TZ's AUC in the absence of ITZ (P<0.05). As a result, single simultaneous administration of TZ with ITZ and single administration of TZ after daily pretreatment with ITZ to rats, ITZ seriously interfered with the pharmacokinetic parameters of TZ in plasma and brain micodialysate.

Dose-response effects of zaleplon as compared with triazolam (0.25 mg) and placebo in chronic primary insomnia

The effects of two nights of treatment with the short-acting benzodiazepine receptor agonist zaleplon, triazolam, or placebo was assessed in chronic primary insomniacs using two concurrent, multi-center, randomized, double-blind, Latin Square crossover studies. Study 1 (n = 47) compared zaleplon (10 and 40 mg) to triazolam (0.25 mg) and placebo. Study 2 (n = 36) compared zaleplon (20 and 60 mg) to triazolam (0.25 mg) and placebo. For each study, polysomnographically recorded sleep parameters and patient reports of sleep quality were collected during baseline and two consecutive nights during the four treatment phases in each study. All doses of zaleplon produced significant decreases in latency to persistent sleep. Although no minimally effective dose could be determined, dose-response effects were apparent. Triazolam 0.25 mg produced a decrease in latency to persistent sleep that was comparable to that of zaleplon 10 mg. Only the triazolam dose and the 60 mg dose of zaleplon produced significant increases in total sleep time over placebo. Zaleplon 40 and 60 mg and triazolam produced decreases in the percentage of REM sleep compared to placebo. Patient reports of efficacy were consistent with objective findings. In addition, all doses of zaleplon tended to increase while triazolam decreased the percentage of stage 3/4 sleep. There was no evidence of residual daytime impairment for any of the zaleplon doses, however, triazolam administration produced significant impairment in performance on a digit copying test. A higher number of adverse events were seen with the 40 and 60 mg doses of zaleplon compared to triazolam (0.25) and placebo. At higher doses, zaleplon is more effective than triazolam at reducing latency to persistent sleep in chronic insomnia and is not associated with the decrease in slow-wave sleep or residual impairment observed with triazolam. However, increases in total sleep time were apparent only at doses which produced concomitant increases in the number of adverse events. In contrast, triazolam (0.25 mg) produced increases in total sleep time (;25 min) and decreases in latency to persistent sleep at a dose of 0.25 mg. Copyright 2000 John Wiley & Sons, Ltd.

Hypnotic self administration and dose escalation

The dependence liability of benzodiazepines in the context of their use as hypnotics (i.e. by insomnia patients as pre-sleep medications) is unresolved. A recent study found that insomniacs self administer capsules at bedtime at a high rate, with triazolam (0.25 mg) taken as often as placebo. This study sought to determine if differential self administration would develop when multiple capsules are available nightly. Eighteen men and women, age 21-45 years, with insomnia complaints (nine with objective sleep disturbance and nine without) were studied, 1 week with placebo and 1 week with triazolam (0.25 mg). The two conditions were administered double-blind and presented in a counter-balanced order with a week between conditions. In each condition, after 3 consecutive sampling nights of the available single capsule for that condition, subjects could self administer 0-3 capsules before bed on the 4 subsequent nights. Triazolam was self administered as many nights as placebo, but the number of placebo capsules self administered was twice that of triazolam capsules. The objective insomniacs self administered more capsules than the subjective insomniacs and neither group differentially choose triazolam over placebo. The number of triazolam capsules taken nightly was stable and the number of placebo capsules variable. It is concluded that insomniacs show no short-term escalation of triazolam dose, but do choose an increased and variable number of placebos, a pattern which is interpreted as being insomnia relief-seeking behavior.

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.

Sensitivity to triazolam in the elderly

BACKGROUND

Elderly persons frequently appear to be sensitive to the effects of many drugs that depress the central nervous system. We studied the effect of age on the pharmacokinetics and pharmacodynamics of the benzodiazepine hypnotic agent triazolam, now the most frequently prescribed hypnotic drug in the United States.

METHODS

Twenty-six healthy young subjects (mean age, 30 years) and 21 healthy elderly subjects (mean age, 69 years) participated in a four-way crossover study. After a single-blind adaptation trial with placebo, each subject received, in random order and in double-blind fashion, single doses of placebo, 0.125 mg of triazolam, and 0.25 mg of triazolam. For 24 hours after the administration of each of the three study medications, plasma triazolam levels were determined and psychomotor performance, memory, and degree of sedation were assessed.

RESULTS

Plasma triazolam concentrations increased in proportion to the dose, but the elderly subjects had higher plasma concentrations due to reduced clearance of the drug. The degree of sedation as rated by an observer and the reduction in the subjects' performance on the digit-symbol substitution test were both greater in the elderly than in the young subjects after they were given the same doses. The relation of the plasma triazolam concentration to the degree of impairment was similar for the two groups. As part of the study, information was presented 1 1/2 hours after the administration of the drugs; the subjects' ability to recall the information 24 hours later was impaired by both doses of triazolam, and the percent decrease was similar in the young and elderly groups.

CONCLUSIONS

Triazolam caused a greater degree of sedation and greater impairment of psychomotor performance in healthy elderly persons than in young persons who received the same dose. These effects resulted from reduced clearance and higher plasma concentrations of triazolam rather than from an increased intrinsic sensitivity to the drug. On the basis of these results, the dosage of triazolam for elderly persons should be reduced on average by 50 percent.

Differential side effect profile of triazolam versus flurazepam in elderly patients undergoing rehabilitation therapy

Patients (aged 65 years or older) who were hospitalized for rehabilitation therapy after a cerebrovascular accident or other acute debilitating condition participated in a 6-week controlled clinical trial. After a 2-week period of receiving nightly single-blind placebo, patients were randomly allocated to receive either triazolam (0.125 mg) or flurazepam hydrochloride (15 mg) nightly under double-blind conditions. For the final 2 weeks, patients again received single-blind placebo. The study groups' were comparable in their performance on four psychomotor tests done in the morning during the initial placebo period. Triazolam-treated patients showed subsequent improvement on the tests, consistent with practice effects, whereas flurazepam recipients showed performance impairment during treatment. Triazolam-flurazepam differences were significant in the card-sorting and arithmetic tests, and they approached significance for the Purdue pegboard test. Blind ratings by physical therapists indicated significant impairment among flurazepam recipients in their capacity to cooperate with and participate in the rehabilitation tasks; the impairment persisted into the post-treatment placebo period. Similar flurazepam-triazolam differences, although not significant, were reported by occupational therapy and nursing staff members. The findings suggest that the kinetic differences between flurazepam and triazolam may have clinical implications in elderly patients undergoing rehabilitation therapy.

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.

Insomnia

Because sleep needs vary from person to person, insomnia is defined as the chronic inability to obtain the amount of sleep needed for optimal functioning and well-being. Insomnia, which is a symptom rather than a disease, can be classified into three main etiologic groups: insomnias related to other mental disorders (for example, depression and anxiety), insomnias related to known organic factors (for example, sleep apnea and "nonrestorative" sleep), and primary insomnia (for example, learned psychophysiologic insomnias and insomnia complaints without objective findings). The treatment for insomnia often involves a combination of pharmacotherapy, behavioral and short-term psychotherapy, and sleep hygiene guidelines. Sleep disorders centers can provide specialized knowledge and techniques for patients with severe chronic insomnia.

Neurochemical and pharmacokinetic correlates of the clinical action of benzodiazepine hypnotic drugs

Benzodiazepine derivatives are presumed to exert their pharmacologic activity via interaction with specific molecular recognition sites, termed benzodiazepine receptors, within the brain. The various benzodiazepines used in clinical practice differ considerably in their intrinsic receptor affinity, but the qualitative character of the drug-receptor interaction is similar or identical among this class of drugs. All benzodiazepines are lipophilic (lipid-soluble) substances that relatively rapidly cross the blood-brain barrier and equilibrate with brain tissue. After equilibrium is attained, a constant brain:plasma ratio is maintained, such that plasma concentrations proportionately reflect concentrations of drug in brain. Brain concentrations are proportional to the extent of receptor occupancy, which in turn determines the acute behavioral effect. Clinical differences among benzodiazepines largely reflect differences in pharmacokinetic properties. The onset of action after single oral doses reflects the rate of absorption from the gastrointestinal tract, whereas the duration of action is determined by the rate and extent of drug distribution to peripheral tissues, as well as by the rate of elimination and clearance. During multiple dosage, long half-life drugs accumulate, with the concurrent possibility of daytime sedation. However, a benefit of long half-life drugs is that rebound insomnia on abrupt termination is unlikely. Short half-life drugs accumulate minimally and have a lower likelihood of producing daytime sedation. However, they may be more likely to produce rebound insomnia on abrupt discontinuation.

Appropriately treating insomnia with triazolam

Insomnia is a problem that extends beyond the nighttime. People who experience sleep disturbances complain that they stay awake for a long time before they fall asleep. They may wake up several times during the night and cannot return to sleep and/or they wake up early in the morning. As a result, they feel sleepy during the day and are less alert. Various forms of insomnia are described that require--as much as possible--an individualized treatment approach. Besides sleeping hygiene, benzodiazepines certainly occupy a place in the treatment of insomnia. Triazolam, a triazolobenzodiazepine, closely approaches the characteristics of an ideal hypnotic: pharmacological activity at the level of the receptors, moderate absorption, short-acting, and rapid elimination. It is effective and safe if prescribed correctly and at the appropriate dosage.

Chronic benzodiazepine administration. IV. Rapid development of tolerance and receptor downregulation associated with alprazolam administration

The triazolobenzodiazepine compound alprazolam may have unique clinical effects compared to other benzodiazepines, and both behavioral and neurochemical studies have indicated unusual results after acute doses of alprazolam. To determine the effects of chronic dosage in mice, alprazolam (2 mg/kg/day) was administered via osmotic pumps for 1-14 days, and open-field activity, plasma and brain concentrations, benzodiazepine receptor binding in vivo and in vitro, [35S]t-butylbicyclophosphorothionate ([35S]TBPS) binding, and muscimol-stimulated chloride uptake were determined. Alprazolam decreased motor activity after 1 and 2 days, but tolerance developed by day 4 and persisted to day 14. Plasma and brain concentrations remained constant during the 2-week period. Benzodiazepine receptor binding in vivo was decreased at day 4 compared to day 1 in cortex (CX) and hypothalamus (HYPO), and remained depressed to day 14 in CX but not HYPO. Benzodiazepine binding in vitro and [35S]TBPS binding were decreased in CX at day 7. Muscimol-stimulated [36Cl-] uptake was decreased at days 4 and 7 compared to day 1, but at day 14 uptake was similar to day 1. These results indicate that behavioral tolerance and receptor downregulation develop rapidly during chronic alprazolam administration. Behavioral and neurochemical changes were similar to those associated with lorazepam administration, but occurred more rapidly and with different regional specificity.

Triazolam kinetics: interaction with cimetidine, propranolol, and the combination

Nineteen healthy volunteers received a single 0.5-mg oral dose of triazolam on four occasions under the following conditions: (1) triazolam alone; (2) triazolam with cimetidine, 300 mg four times daily; (3) triazolam with propranolol, 40 mg four times daily; (4) triazolam with both cimetidine and propranolol. Triazolam kinetics were determined from multiple plasma concentrations measured during 24 hours after each dose. Compared with control, peak plasma triazolam concentration (Cmax) was significantly increased by cimetidine (5.4 versus 3.9 ng/mL), total area under the plasma concentration curve (AUC) increased (21.3 versus 16.1 ng/mL X hr), and oral clearance decreased (485 versus 668 mL/min). However triazolam half-life was not increased. During propranolol alone, triazolam Cmax (4.1 ng/mL), AUC (14.3 ng/mL X hr), and clearance (759 mL/min) did not differ significantly from control, whereas kinetic variables for triazolam with cimetidine plus propranolol were similar to those with cimetidine alone. Plasma free fraction for triazolam (17 to 18% unbound) did not differ significantly among the four treatment conditions. Mean steady-state plasma cimetidine concentrations during trials 2 and 4 were similar (1.04 versus .98 micrograms/mL), whereas plasma propranolol was significantly higher during cimetidine plus propranolol than with propranolol alone (47 versus 29 ng/ml, P less than .001). Thus cimetidine coadministration significantly inhibits triazolam clearance, causing increased triazolam AUC and Cmax, but without a prolongation in half-life. Propranolol itself does not impair triazolam clearance, nor does propranolol potentiate the inhibitory effect of cimetidine alone.

The natural history of tolerance to the benzodiazepines

Dependence on benzodiazepines following continued use is by now a well-documented clinical phenomenon. Benzodiazepines differ in their dependence potential. The present studies were aimed at examining the possibility that differential rates of tolerance development might account for differences in dependence risk. Four studies are reported. The first three studies concerned normal subjects. The development of tolerance over a fifteen day period was demonstrated for three different benzodiazepines (ketazolam, lorazepam and triazolam) using two paradigms. Tolerance in terms of a reduction in effectiveness of a repeated given dose was most notable for the benzodiazepine with a medium elimination half-life (lorazepam) for physiological, behavioural and subjective measures. In the case of the drug with the longest elimination half-life (ketazolam) reduction in effectiveness could only be assumed to be occurring if account was taken of the steady increase in plasma concentrations of active metabolites. For this drug it seemed that the physiological measures were those most likely to demonstrate the development of tolerance. Although triazolam showed few significant drug effects on this paradigm (testing being 12 hours after ingestion of this short half-life benzodiazepine), tolerance was seen to develop on some subjective measures. Using an alternative method of testing tolerance, assessing responses to a diazepam challenge dose, a high degree of tolerance on two-thirds of the measures was observed in subjects when pretreated with the benzodiazepine with the most marked accumulation of active metabolites (ketazolam). The other two drugs also led to tolerance development on a range of measures; this was more marked for lorazepam than triazolam. Blunting of the growth hormone response to diazepam was the most sensitive and reliable method of detecting tolerance to the benzodiazepines. Symptoms on discontinuation of the two weeks' intake of the benzodiazepines were marked for all the drugs but unrelated to either the tolerance induced or the elimination half-life of the particular drug. A further clinical study revealed that tolerance persisted in a group of long-term benzodiazepine users for between four months and two years following complete abstinence from the drug. These patients appeared to be less affected by diazepam in terms of its commonly observed subjective effects, regardless of their original medication. These ex-long-term users of benzodiazepines were, however, more likely to manifest two specific types of effects--immediate 'symptom' reduction and exacerbation of 'withdrawal symptoms' over the subsequent week.(ABSTRACT TRUNCATED AT 400 WORDS)

Specific effects of sedative/hypnotic drugs in the treatment of incapacitating chronic insomnia

Sedative/hypnotic drugs for the treatment of chronic insomnia are generally considered ineffective by most experts but helpful by many patients. Occasionally, insomnia-induced debilitations may be remedied by long-term use of sedative/hypnotic drugs; some examples are given. The present discrepancy between expert and patient opinion may be derived from current research practices. The improbability that series of sedative/hypnotic drug trials will be carried out for patients with insomnia further biases against observation of rarer but clinically significant distinctions among these drugs.

Effect of gradual withdrawal on the rebound sleep disorder after discontinuation of triazolam

Sixty volunteers with insomnia participated in a randomized, double-blind, controlled clinical trial. After an initial six nights of placebo, 30 subjects (the abrupt-withdrawal group) received 0.5 mg of triazolam nightly for 7 to 10 nights, after which they received placebo. The other 30 subjects (the tapered-dosage group) received the same initial placebo treatment, then triazolam at 0.5 mg for seven nights, at 0.25 mg for two nights, and at 0.125 mg for two nights, and then placebo. As compared with the initial placebo period, the triazolam period significantly reduced the interval before the onset of sleep (sleep latency), and it prolonged sleep duration, reduced the number of awakenings, and improved the self-rated soundness of sleep in all cohorts. In the abrupt-withdrawal group, plasma levels of triazolam were undetectable the morning after the first night of placebo substitution, and subjects reported prolongation of sleep latency (57 minutes longer than base line), reduction in sleep duration (1.4 hours less than base line), and increased awakenings (1.2 per night above base line). The symptoms of rebound sleep disorder lasted one or possibly two nights, and there was a reversion toward base line on subsequent placebo nights. In the tapered-dosage group, however, plasma triazolam levels fell gradually to zero, and rebound symptoms were decreased or eliminated. Thus, rebound sleep disorder following abrupt discontinuation of triazolam can be attenuated by a regimen of tapering.

Bidirectional changes in the consumption of food produced by beta-carbolines

beta-Carboline derivatives provide examples of benzodiazepine receptor ligands which span the range: full agonist-partial agonist-antagonist-partial inverse agonist-full inverse agonist. Taken together, the effects of these compounds illustrate two important principles: firstly, the bidirectionality of effects which can be achieved using benzodiazepine receptor ligands; secondly, the selectivity of effects which are produced by partial agonists. Applied to the study of feeding processes, these principles imply that both hyperphagic and anorectic effects can be generated by actions of selected ligands at benzodiazepine receptors. Furthermore, they suggest that a hyperphagic effect may occur in the absence of side-effects (e.g., sedation, muscle-relaxation), which are characteristic of classical benzodiazepines. Experimental data in support of these predictions are presented. A microstructural approach to feeding behavior indicated that a benzodiazepine receptor agonist and an inverse agonist extend and abbreviate, respectively, the duration of individual bouts of eating. Preference for a saccharin solution was attenuated by the beta-carboline inverse agonist, FG 7142, but rejection of a quinine solution was not increased. Adrenalectomy had no effect on the anorectic effect of inverse agonists.

Lack of influence of cigarette smoking on triazolam pharmacokinetics

The influence of cigarette smoking on the pharmacokinetics of a single dose of the triazolobenzodiazepine hypnotic triazolam was evaluated in 12 healthy nonsmoking male volunteers and in 12 male subjects, matched for age, height and weight, who smoked an average of 24 cigarettes a day (range: 15-30). Triazolam kinetics were determined from multiple serum concentrations measured during 15 h after a single 0.5 mg dose. There were no significant differences between nonsmoking controls and cigarette smokers in the peak serum triazolam concentration (4.64 vs 4.73 ng ml-1), the time of peak concentration (0.98 vs 1.0 h after dosage), elimination half-life (2.8 vs 2.5 h), or oral clearance of triazolam (506 vs 627 ml min-1). Likewise there were no significant differences between groups in the extent of triazolam binding to serum protein (18.8 vs 18.5% unbound). Altered pharmacodynamics of triazolam in cigarette smokers are not likely to be explained by altered pharmacokinetics.

Population study of triazolam pharmacokinetics

The kinetics of a single 0.5 mg oral dose of the triazolobenzodiazepine hypnotic triazolam, were studied in 54 healthy young men aged 20-44 years, with a mean body weight of 77 kg. Triazolam kinetics were determined from multiple plasma concentrations measured during 14 h post-dose. The overall mean +/- s.e. mean (with range) kinetic variables were: peak plasma concentration, 4.4 +/- 0.3 (1.7-9.4) ng ml-1; time of peak, 1.3 +/- 0.1 (0.5-4.0) h after dose; elimination half-life, 2.6 +/- 0.1 (1.1-4.4) h; total AUC: 19.1 +/- 1.1 (4.4-47.7) ng ml-1 h; oral clearance, 526 +/- 38 (175-1892) ml min-1. All kinetic variables were consistent with Poisson distributions, based on the Kolmogorov-Smirnov Goodness of Fit test. None of the variables fit normal distributions. Four of five were consistent with a log normal distribution. Peak plasma level was highly correlated with clearance (r = -0.85, P less than 0.0001), and AUC (r = 0.85, P less than 0.0001) but not with body weight (r = 0.21, NS). Clearance and body weight were not correlated (r = -0.01). Triazolam clearance may vary widely even within a homogeneous group of healthy young men.

The clinical use of hypnotics: indications for use and the need for a variety of hypnotics

Insomnia may be categorized as difficulty falling asleep, frequent awakening, early awakenings or a combination of each. The ideal hypnotic must promote rapid sleep onset and maintain sleep throughout the night while allowing the patient to awake refreshed the following day. Several benzodiazepines, with differing pharmacokinetic and pharmacodynamic profiles are presently available. All are clinically effective and not only elimination half-life but also dosage prescribed and pattern of distribution are important factors for determining treatment response. Hypnotics have been divided into those with long elimination half-lives (e.g. nitrazepam, flunitrazepam, flurazepam), those with intermediately long half-lives (brotizolam, loprazolam, lormetazepam, temazepam) and those with short half-lives (midazolam and triazolam). Carry-over effects into the morning such as excessive daytime sleepiness or drowsiness are related to drug half-life, dosage and pattern of distribution. In equipotent dosages most controlled clinical trials have found no significant differences between the various benzodiazepine hypnotics. Nevertheless, clinicians in general tend to use long half-life benzodiazepines in patients who have difficulties maintaining sleep and short half-life benzodiazepines for treating sleep onset insomnia. Intermediately long half-life, benzodiazepines are used for both indications and most clinicians feel that the choice of hypnotic should not only be influenced by elimination half-life or the dosage used, but by individual patient preference. Hypnotics should be used for only short periods of time and in those patients for whom a more chronic use is indicated, they should be used only on an intermittent basis.

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.

Efficacy of a reduced triazolam dose in elderly insomniacs

Elderly persons with insomnia are unique because the cause of their insomnia differs from that of younger people and their metabolism of benzodiazepine hypnotics differs as well. This study used nocturnal polysomnography and daytime sleep/wake tendency measures (Multiple Sleep Latency Test, MSLT) to assess the efficacy and safety of a reduced triazolam dosage (0.125 mg) in elderly subjects with insomnia. After 2 nights and an intervening day of screening each subject received triazolam and placebo for 2 consecutive nights presented in a counter-balanced design. Compared to placebo the reduced triazolam dose induced and maintained sleep thereby increasing total sleep time. Sleep stage distribution and the frequency of apneas and periodic leg movements was not altered. The improved sleep was associated with a restoration of the normal pattern of daytime alertness. The correspondence of this clinical data to known pharmacokinetic data is discussed.

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.

Prolonged hypnotic response to triazolam-cimetidine combination in an elderly patient

An 82-year-old white female developed a 36-hour episode of unresponsiveness/drowsiness after a single dose of triazolam 0.5 mg in combination with cimetidine. This case illustrates the need for careful dose-titration of drug therapy in the elderly, particularly when a drug with the potential to impair drug metabolism is coadministered. Cimetidine, when coadministered with triazolam, may increase the intensity and duration of action of single doses of triazolam.

A comparative 25-night sleep laboratory study on the effects of quazepam and triazolam on chronic insomniacs

The short- and intermediate-term actions, as well as the carryover and withdrawal effects, of quazepam , a new benzodiazepine hypnotic with a half-life of 60 to 100 hours, were compared with those of triazolam, a triazolodiazepine hypnotic with a half-line of 2 to 3 hours. Both the subjective effects of these drugs as well as their objective actions on the sleep EEG were sought. The study was conducted on two groups of six subjects with chronic insomnia who ranged in age from 32 to 56 years. Each subject was studied for 25 consecutive nights. Placebo was administered at bedtime on the first four nights, followed by 30 mg quazepam or 0.5 mg triazolam on the next 14 nights and by placebo again on the ensuing seven withdrawal nights. Both drugs increased the total sleep time during their administration and improved the subjective quality of sleep. Major differences, however, were observed on withdrawal. A significant and marked decrease in the total sleep time occurred with triazolam on the first withdrawal night. With quazepam , rebound insomnia was not observed at any time during the seven-day withdrawal period.

Effects of brotizolam on the sleep of chronic insomniacs

Effects of 0.5 mg brotizolam on the sleep of chronic insomniacs were assessed electroencephalographically and subjectively over 14 days. Brotizolam (0.5 mg) increased total sleep time, decreased drowsy (stage 1) sleep and increased stage 2 sleep. At this dose it also decreased slow wave and rapid eye movement sleep. On withdrawal there was evidence of insomnia in some subjects during the first night. The drug was well tolerated. Further studies are indicated with lower doses of the drug.