A dose response study of the hypnotic effectiveness of alprazolam and diazepam in normal subjects

GHB: a new and novel drug of abuse

There has been increasing attention in the United States to problems of abuse of gamma-hydroxybutyrate (GHB), with some evidence for problems in other parts of the world as well. In vitro and animal research show that, while GHB shares some properties with abused central nervous system depressant drugs, it has unique aspects of its pharmacology as well, including actions at a specific neural receptor which probably mediates many of its effects. Abuse potential assessment of GHB using standard animal models has not yielded a picture of a highly abusable substance, but little human testing has yet been done. Very little systematic data exist on tolerance and dependence with GHB, but both have been seen in human users. Quantitative data on the prevalence of GHB abuse is incomplete, but various qualitative measures indicate that a mini-epidemic of abuse began in the late 1980s and continues to the present. GHB is often included with the group of 'club drugs', and can be used as an intoxicant. It also has been used as a growth promoter and sleep aid and has been implicated in cases of 'date rape', usually in combination with alcohol. Undoubtedly the easy availability of GHB and some of its precursors has contributed to its popularity. Recent changes in the control status of GHB in the US may reduce its availability with as yet unknown consequences for the scope of the public health problem. Drug abuse experts need to familiarize themselves with GHB as possibly representing a new type of drug abuse problem with some unique properties.

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.

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.

Circadian rhythms and the pharmacology of affective illness

The chronic effects of antidepressant drugs (ADs) on circadian rhythms of behavior, physiology and endocrinology are reviewed. The timekeeping properties of several classes of ADs, including tricyclic antidepressants, selective serotonin reuptake inhibitors, monoamine oxidase inhibitors, serotonin agonists and antagonists, benzodiazepines, and melatonin are reviewed. Pharmacological effects on the circadian amplitude and phase, as well as effects on day-night measurements of motor activity, sleep-wake, body temperature (Tb), 3-methoxy-4-hydroxyphenylglycol, cortisol, thyroid hormone, prolactin, growth hormone and melatonin are examined. ADs often lower nocturnal Tb and affect the homeostatic regulation of sleep. ADs often advance the timing and decrease the amount of slow wave sleep, reduce rapid eye movement sleep and increase or decrease arousal. Together, AD effects on nocturnal Tb and sleep may be related to their therapeutic properties. ADs sometimes delay nocturnal cortisol timing and increase nocturnal melatonin, thyroid hormone and prolactin levels; these effects often vary with diagnosis, and clinical state. The effects of ADs on the coupling of the central circadian pacemaker to photic and nonphotic zeitgebers are discussed.

An integrative analysis to sleep functions

Various studies suggest that some sleep functions, especially some slow wave sleep functions, are indispensable in mammals and related to brain regulation. It has been proposed that two of these functions are the adjustment of emotional balance and the processing of acquired emotional memories. During waking, the gradual accumulation of various randomly learned emotional memories in the limbic structures would inevitably imbalance and disorganize emotional behaviors. Although the emotional balance can be restored during waking by the ascending NA, DA, ACh and 5-HT systems, their roles in memory retention and emotional regulation may sometimes be dissociated and their adjustment of the emotional balance can only be a transient effect. On the other hand, the function of slow wave sleep for emotional adjustment can be long-lasting and is in agreement with its function on the processing of emotional memories. As a result, these sleep functions become indispensable in preventing the emotional imbalance inevitably caused by the accumulation of emotional memories. The effects of rapid eye movement sleep on memory and emotional regulation are just opposite to those of slow wave sleep. Low vigilance is required as premise for sleep to accomplish these indispensable functions.

A guide to benzodiazepine selection. Part II: Clinical aspects

To suit the specific needs of various clinical situations, selection of an appropriate benzodiazepine derivative should be based on consideration of their different pharmacokinetic and pharmacodynamic properties. Benzodiazepine derivatives that are rapidly eliminated produce the most pronounced rebound and withdrawal syndromes. Benzodiazepines that are slowly absorbed and slowly eliminated are most appropriate for the anxious patient, since these derivatives produce a gradual and sustained anxiolytic effect. Rapidly absorbed and slowly eliminated benzodiazepines are usually more appropriate for patients with sleep disturbances, since the rapid absorption induces sleep and the slower elimination rate may induce less tolerance to the sedative effect. Rational selection of a benzodiazepine for the elderly and for the suspected drug abuser is more problematic. The relevant pharmacokinetic and clinical considerations for these users are discussed. Certain derivatives may possess pharmacodynamic properties not shared by the entire benzodiazepine class; empirical studies have suggested the existence of anti-panic properties for alprazolam and clonazepam, antidepressant properties for alprazolam, and anti-manic properties for clonazepam and possibly lorazepam.

Drug effects on REM sleep and on endogenous depression

In earlier work REM sleep deprivation (RSD) by arousals improved endogenous depression. This suggested that drugs producing a similar RSD would have antidepressant activity. The arousal RSD was large, persisted for weeks, and was followed by a REM rebound. We call RSD with these properties arousal-type RSD. The present study reviewed literature from 1962 to 1989 on drug REM sleep effects to examine the hypothesis that drugs producing arousal-type RSD improve endogenous depression. The literature reviewed concerned the REM sleep effects of amine precursors, antidepressants, antihistamines, antipsychotics, barbiturates, benzodiazepines, other hypnotics, drugs affecting cholinergic and noradrenergic neurotransmission, ethanol, lithium and narcotics. Four hundred and sixty-eight relevant papers were read and 215 contributed information that could be used in the review. The findings indicated that all drugs producing arousal-type RSD improved endogenous depression. Four drugs that improved endogenous depression did not produce arousal-type RSD.

Dose level effects of triazolam on sleep and response to a smoke detector alarm

Thirty-six young adult, male subjects with sleep-onset insomnia were equally divided into placebo, 0.25 mg, and 0.5 mg triazolam groups to examine the effects of the hypnotic, with particular attention to dose level on efficacy, sleep stages, and awakening to a smoke detector alarm. On nights 1 and 4 of a five-consecutive-night protocol, a standard home smoke detector alarm was sounded during stage 2, 5 min after sleep onset, in slow wave sleep (SWS), and at the time of the early morning awakening. The alarm registered 78 dB SPL at the pillow. EEG arousal latency and reaction time to a button press were studied. Failure to awaken to three 1-min alarm presentations was scored as "no response." Both dose levels produced similar reductions in sleep latency, decreases in SWS, increases in stage 2, and increases in sleep efficiency. Both dose levels showed similar sedative effects to the smoke alarm. Fifty percent of triazolam subjects failed to awaken on night 1 during SWS, and EEG arousal and response latencies were significantly slowed. Some drug tolerance or sensitization to the alarm was seen by night 4. By morning, all subjects were easily awakened on both nights. The 0.25 mg dose is clearly an effective dose level for both sleep efficacy and sedative effects to outside noise, which in some instances could pose potential problems.

Task-dependent development of cross-tolerance to psychomotor effects of lorazepam in man

Development of cross-tolerance between lorazepam and four other benzodiazepines (BZ) was studied in two trials by measuring objective psychomotor performance and by subjective assessments. In trial I, nitrazepam 10 mg (NZ), temazepam 20 mg (TZ) or placebo were administered to 14 healthy students for 10 consecutive nights. After each pretreatment, psychomotor impairment by the challenge dose of lorazepam 3 mg (LZ) was measured. In trial II, responses to LZ after pretreatment with diazepam 5 mg (DZ) (8 subjects) or alprazolam 0.25 mg (AZ) (10 subjects), both t.i.d., were compared to LZ responses measured after one-month wash-out period. In trial I no cross-tolerance between BZs was found in objective tests, and LZ induced exophoria was even increased. However, the subjects rated LZ to cause less drowsiness after pretreatment with NZ in a situation where the manifestation of cross-tolerance was facilitated by ingestion of caffeine. In trial II a clear but task-dependent development of tolerance to the challenge dose of LZ was documented. One-week pretreatment with DZ reduced subjects responses to LZ. The total serum BZ activity bioassayed by radioreceptor method after intake of LZ was significantly (P less than 0.05) higher after pretreatment with DZ than in the end of wash-out period. Thus a functional cross-tolerance was documented on complex tasks after the subjects have been continuously working under DZ burden.

A double-blind comparison of alprazolam vs. imipramine and placebo in the treatment of major depressive disorder

In a 6-week double-blind trial 129 outpatients with major depressive disorder received either alprazolam, imipramine or placebo. Dosage was adjustable from 0.5 mg alprazolam, 25 mg imipramine or two capsules placebo b.i.d. to 4.5 mg alprazolam, 225 mg imipramine or three capsules placebo t.i.d. Both active drugs were more effective than placebo according to all the rating scales used. Alprazolam and imipramine did not differ consistently except in the somatic symptom cluster on the Hamilton Anxiety Rating Scale. Mean final daily dosage was 2.7 mg alprazolam, 117.3 mg imipramine and 7.2 capsules placebo. Patients on alprazolam reported fewer side effects than patients on imipramine and approximately the same number as patients on placebo. Anticholinergic side effects were commonly associated with imipramine; drowsiness was the most frequent side effect with alprazolam.

Alprazolam: pharmacokinetics, clinical efficacy, and mechanism of action

Alprazolam, a triazolobenzodiazepine, is the first of this new class of benzodiazepine drugs to be marketed in the United States and Canada. It achieves peak serum levels in 0.7 to 2.1 hours and has a serum half-life of 12 to 15 hours. When given in the recommended daily dosage of 0.5 to 4.0 mg, it is as effective as diazepam and chlordiazepoxide as an anxiolytic agent. Its currently approved indication is for the treatment of anxiety disorders and symptoms of anxiety, including anxiety associated with depression. Although currently not approved for the treatment of depressive disorders, studies published to date have demonstrated that alprazolam compares favorably with standard tricyclic antidepressants. Also undergoing investigation is the potential role of alprazolam in the treatment of panic disorders. Alprazolam has been used in elderly patients with beneficial results and a low frequency of adverse reactions. Its primary side effect, drowsiness, is less than that produced by diazepam at comparable doses. Data on toxicity, tolerance, and withdrawal profile are limited, but alprazolam seems to be at least comparable to other benzodiazepines. Drug interaction data are also limited, and care should be exercised when prescribing alprazolam for patients taking other psychotropic drugs because of potential additive depressant effects.