The effects of quazepam,triazolam, flunitrazepam and placebo,alone and in combination with ethanol,on day-time sleep,memory, mood and performance

Day-time sleep and residual effects of quazepam 15 mg, triazolam 0·25 mg, flunitrazepam 1 mg, and placebo, alone and in combination with ethanol, were studied using a randomized, double-blind, crossover, single-dose design. Eight healthy volunteers, four male and four female, aged 19–24 years, received each medication in the morning after a ‘normal’ sleep at home the preceding night. Quazepam and triazolam decreased the sleep onset when compared to placebo. The combination with ethanol did not change these findings. Quazepam and placebo showed less residual effects than triazolam and flunitrazepam at 4 hours after drug intake: in combination with ethanol at 4 and 6 hours. No significant differences in mood were found between the different ‘treatments’, except with regard to alertness for quazepam and placebo compared to flunitrazepam, alone and in combination with ethanol, all at 4 hours. The combination drug/ethanol showed an increase in C_max of the former and a delay in T_max when compared to drug alone. The study indicated few clinically useful correlations between clinical effect and plasma concentration.     

Amnesic effects and subjective ratings during repeated dosing of flunitrazepam to healthy volunteers

Summary Flunitrazepam (1 mg) or placebo was administered once daily over a treatment period of 8 days to healthy, male volunteers to study the time course of the effects on memory functions and on subjective ratings of alertness and tension. The plasma level of flunitrazepam increased by approximately 40% (P<0.05) during the treatment period. The mean pre-dose level of flunitrazepam on day 4 and day 8 was approximately 0.005 M, and no residual effects on memory functions were observed. Intake of flunitrazepam decreased the number of freely recalled words by about 85% (P<0.05) and significantly affected the subjects' rating of attention when tested during the first few hours after drug intake on day 1 of treatment. However, no significant effect on the subjects' rating of relaxation was observed. When tested similarly after 8 days treatment, flunitrazepam significantly affected the subjects' rating of relaxation (P<0.01). Furthermore, no tolerance developed for the effect of flunitrazepam on free recall (P>0.3) and the subjects' rating of attention (P>0.7), and these effects had nearly equal time courses during the treatment period. This may indicate that the amnesic effect of benzodiazepines is at least partially mediated through the effects on attention or general arousal. Two of the subjects in the active drug group reported adverse reactions or incidents of discomfort during the 1st week following the treatment period, whereas none in the placebo group reported such reactions.     

Double-blind comparison of zopiclone and flunitrazepam in elderly insomniacs with special focus on residual effects

Summary

In a double-blind study of 102 patients with a mean age of 79 years, zopiclone was compared to flunitrazepam. The patients rated their sleep in a diary. There was no statistically significant difference between the relatively low dose of 5?mg zopiclone and 1?mg flunitrazepam for eleven out of the twelve variables measuring subjective sleep quality and quantity. There were no differences between the drugs as regards patients' feelings of being rested or alertness.     

Residual effects of zolpidem 10 mg and zopiclone 7.5 mg versus flunitrazepam 1 mg and placebo on driving performance and ocular saccades

Rationale: Studies report contradictory results concerning the residual effects of zolpidem and zopiclone. Moreover, residual effects of these compounds on healthy subjects have not yet been simultaneously assessed. Objective: The present study with healthy subjects investigated the residual effects of zolpidem 10 mg and zopiclone 7.5 mg on driving performance and on ocular saccade and compared them to those under flunitrazepam 1 mg and placebo. Methods: The study involved 16 subjects divided into two groups, a 9:00 a.m. group and a 11:00 a.m. group, in a balanced, double-blind, cross-over design. Results: In the 9:00 a.m. group, zolpidem had no residual effects while zopiclone and flunitrazepam both impaired driving performance (P < 0.001 for both) and increased saccadic latency (P < 0.005; P = 0.052, respectively). Zopiclone impaired driving performance 5 times less than did flunitrazepam. In the 11:00 a.m. group, zolpidem and zopiclone had no residual effects, while flunitrazepam increased saccadic latency (P = 0.065) but did not impair driving performance. Conclusions: Zopiclone and flunitrazepam had residual effects in the first part of the morning, whereas zolpidem had no residual effects. The hierarchical character of the effects of the molecules differed according to the test administered. This is probably linked more to drug-induced specific alterations than to different sensitivities of the tests. Received: 30 April 1998/Final version: 2 December 1998     

Pharmacokinetic and clinical observations on prolonged administration of flunitrazepam

Summary Eight patients were given flunitrazepam 2 mg orally, once daily for 28 consecutive days. The time-course of the plasma concentration of unchanged flunitrazepam and its principal metabolites were studied in detail after the first and last doses. Additional blood samples were collected immediately before administration of the tablet on days 4, 7, 11, 14, 18, 21 and 25. Clinically there were no changes during the trial period in the onset of sleep, duration of sleep, depth of sleep measured as number of spontaneous awakenings, or in the patients' condition on awakening. The time-course of the plasma concentration of flunitrazepam could be described by a three-compartment model, assuming that the rate constants remained unchanged during treatment. Maximal plasma concentrations of unchanged flunitrazepam, found two hours after intake, reached 10–15 ng/ml after the first and 15–20 ng/ml after the last dose. The -half-life was found to be between 20 and 36 h.     

Hypnotic action of flunitrazepam in the rat: Does 5-HT mechanism play a role?

This study examined whether pharmacological manipulation of serotonergic (5-HT) systems would affect the hypnotic action of flunitrazepam in rats. Flunitrazepam, a potent hypnotic, was used alone or combined with parachlorophenylalanine (pCPA), an inhibitor of the synthesis of 5-HT, 8-OH-DPAT, a 5-HT_1A receptor agonist and fluvoxamine, an inhibitor of the reuptake of 5-HT. Flunitrazepam increased the amount of orthodox sleep, the latency of rapid eye movement (REM) sleep and decreased the amount of REM sleep. The drug pCPA decreased the total sleep time and the amount of orthodox and REM sleep. Administration of flunitrazepam to pCPA-pretreated rats induced orthodox sleep in an identical way to that found in the controls. The drug 8-OH-DPAT increased wakefulness and the latency of REM sleep. The association of flunitrazepam with 8-OH-DPAT abolished the increase in waking seen after 8-OH-DPAT alone. In contrast, the combined treatment with flunitrazepam and 8-OH-DPAT resulted in a lengthening of the latency of REM sleep significantly greater than that observed with the same dose of each drug alone. Fluvoxamine increased the latency and decreased the amount of REM sleep. The association of fluvoxamine with flunitrazepam induced a decrease in REM sleep, equal to the sum of the effects of the two drugs alone. Fluvoxamine did not modify the other effects of flunitrazepam. The present experiments demonstrate that the association of pCPA, 8-OH-DPAT and fluvoxamine, did not alter the hypnogenic effect of flunitrazepam. The possibility of an involvement of 5-HT mechanisms in the effect of flunitrazepam on the phasic events in sleep is questionable.     

Residual effects of zopiclone on subsequent daytime functions in normal humans

The influence of zopiclone and nitrazepam on arousal level, muscle strength, psychomotor performance and memory function using the photopalpebral reflex (PPR), critical flicker frequency (CFF), tapping test, pursuit rotor test (PRT), choice reaction test (CRT) and memory drum test (MDT) were investigated on the day following drug administration. After the control tests were completed at 1800 h, nine healthy male university students were given zopiclone 10 mg, nitrazepam 10 mg and placebo in a double-blind, crossover design at 2300 h. The performance on the tests, as well as the recording of subjective assessments, were repeated at 0800, 1100 and 1400 h the next day. Both nitrazepam and zopiclone produced a prolongation of PPR latency and a decrease of CFF. The effects of zopiclone were weaker and shorter in duration than those of nitrazepam. Tapping rate, PRT and CRT improved or did not change, and there were no significant differences between the drugs. The MDT was impaired by both drugs in the morning, with nitrazepam continuing to produce memory impairment, while zopiclone did not produce further deterioration. No significant changes were observed in the subjective assessment of the subjects. These results suggest that a medium dose of zopiclone lowers arousal level and impairs memory, especially during the morning following drug administration, but produces no change in muscle strength, psychomotor performance or self-assessment. Finally, the residual effects of zopiclone appear to be weaker than those of nitrazepam.     

Residual effect of single and repeated doses of midazolam and nitrazepam in relation to their plasma concentrations

Summary Twelve healthy volunteers were given either midazolam 15 mg or nitrazepam 5 mg for 7 consecutive days in a randomized cross-over trial. Self-assessment of sleep, mood or condition on awakening and adverse effects was performed, and the volunteers underwent evaluation of psychomotor performance. Hypnotic effect, judged by the classical sleep variables, showed that the drugs were more or less equal and were superior to placebo. Nitrazepam consistently produced an impaired condition on awakening and also clearly displayed a spectrum of adverse motor effects. Motor tests revealed impairment induced by both drugs, but, in the midazolam group the effect subsided during the trial period. Both drugs had a significant effect on memory, midazolam appearing to perturb certain memory functions to a greater extent than did nitrazepam. The residual plasma concentration of midazolam 11 h after treatment correlated well with the scores obtained in several of the psychomotor tests, whereas plasma nitrazepam levels were not related to performance in any subtest. When discontinued neither drugs, induced any rebound phenomenon. However, the adverse effects of nitrazepam appeared to be carried over into the adjacent placebo period.     

Stem-completion tasks (indirect, direct inclusion and exclusion) are differently affected by equipotent doses of lorazepam and flunitrazepam

This study was designed to explore the effects on performance in stem-completion tasks of two benzodiazepines (BZ) in equipotent doses: lorazepam, a drug that atypically disrupts perceptual priming, and flunitrazepam, a compound with standard BZ effects. The study followed a placebo-controlled, double-blind, parallel-group design. Thirty-six young and healthy subjects carried out three completion tasks at theoretical peak-plasma concentrations of drugs: (a) indirect tasks, in which the subjects were instructed to complete stems with the first word that came to mind; (b) direct inclusion tasks/cued recall, in which the participants had to try to use words seen at study as completions; and (c) direct exclusion tasks, in which words seen at study were to be avoided. The PDP was applied to the results in the inclusion and exclusion tasks, to obtain indices of explicit/controlled (C) and implicit/automatic (A) memory. The C index was lowered by both BZs and A was equivalent in all treatments, confirming the general amnestic action of BZs. However, lorazepam led to decreases in completions in the indirect and inclusion tasks, while flunitrazepam impaired performance in the exclusion task. The qualitative differences between the drugs in their effects on performance suggest that these BZs may lead to differences in response bias.     

N-desmethyladinazolam pharmacokinetics and behavioral effects following administration of 10–50 mg oral doses in healthy volunteers

Results of previous studies suggest that N-desmethyladinazolam, the major metabolite of adinazolam in man, contributes substantially to psychomotor effects and sedation observed following adinazolam administration. Therefore, the pharmacokinetics and pharmacodynamics of N-desmethyladinazolam were explored following administration of single oral doses of placebo and solutions containing 10, 30, and 50 mg N-desmethyladinazolam mesylate in a double-blind, randomized, four-way crossover design to 15 healthy male volunteers. Plasma concentrations of N-desmethyladinazolam were determined by HPLC. Psychomotor performance tests (digit symbol substitution and card sorting by fours and suits), memory tests and sedation scoring were also performed following drug administration. N-desmethyladinazolam pharmacokinetics were dose independent over this range. Doserelated performance effects were observed at 1, 2, and 6 h after dosing. Memory was likewise affected at 2 h. Psychomotor performance decrements correlated with log N-desmethyladinazolam plasma concentrations. Analysis of the relationship between percentage decrements in digit-symbol substitution and plasma N-desmethyladinazolam using the Hill equation revealed a EC₅₀ of 325 ng/ml. These results establish the relationship between N-desmethyladinazolam plasma concentrations and performance effects; these data will be helpful in assessing the contribution of N-desmethyladinazolam to clinical effects observed after adinazolam administration.     

Effects of zolpidem 10 mg, zopiclone 7.5 mg and flunitrazepam 1 mg on night-time motor activity.

The effects of a single dose of zolpidem (10 mg), zopiclone (7.5 mg) and flunitrazepam (1 mg) on motor activity the following 3 nights were compared to those of a placebo in a double-blind, crossover study. Thirty-three healthy subjects received medication between 10.30 and 11.30 p.m. and were asked to rise between 7.30 and 8.30 a.m. During the night under treatment, flunitrazepam, zopiclone and zolpidem significantly reduced motor activity. Changes in motor activity are quantitatively compatible with the hypothesis of reduced light sleep and wakefulness after sleep onset. During the first or second post-drug night, for zolpidem and zopiclone the opposite effect was observed, i.e. increased activity compared with placebo. These modifications cannot be explained by modified sleep structure. This last result underlines our inadequate understanding of the underlying mechanisms of motor activity during sleep. However, being sensitive and easy to use, actigraphy is an ideal technique to assess the effect of hypnotics on large populations and for long duration studies.     

Performance and mood following partial sleep deprivation: A randomized,double-blind crossover study of zopiclone,triazolam, flunitrazepam,ethanol and placebo

The effects of zopiclone 7.5 and 15 mg, triazolam 0.25 and 0.5 mg, flunitrazepam 1 and 2 mg, ethanol and placebo on performance, mood and sleep onset latency after partial sleep deprivation, were compared in a randomized, double-blind, crossover, single-dose study. Sixteen healthy volunteers of both sexes, aged 21–31 years, were included in the study. The overall assessment of the total psychological measurement indicated that zopiclone 7.5 mg, triazolam 0.25 mg and ethanol (C_max = 0.40 parts per thousand) did not affect the daytime performance of an unacceptable degree even when given late at light. The findings for flunitrazepam 1 mg were not so uniform, but also seemed acceptable. Zopiclone 15 mg, triazolam 0.5 mg and flunitrazepam 2 mg were rated as not acceptable alternatives. No significant differences were shown concerning mood. The overall assessment for sleep onset latency and subjective alertness indicated that zopiclone 7.5 mg and triazolam 0.25 mg had a more appropriate profile than the other drugs and doses tested.     

Biliary excretion of diazepam and its metabolites in man after repeated oral doses

Summary The concentration of free and conjugated diazepam, of its major demethylated metabolite, N-demethyldiazepam, and of its hydroxylated metabolites, N-methyloxazepam and oxazepam, were measured by a GLC-method in plasma, bile and urine following four nightly doses of diazepam 10 mg. Ten patients with a T-tube in the common bile duct after choledochotomy (Group I) were studied and 12 patients after cholecystectomy (Group II). Twelve hours after drug administration, the mean total concentration of diazepam in bile was 1/23 that in plasma. Similarly, during 9–10 h only low concentrations of diazepam were found in the urine, and in both urine and bile only the unconjugated drug was found. The principal metabolite of diazepam in plasma was N-demethyldiazepam. In bile an average of 77% of the total amount of N-demethyldiazepam was in the conjugated form, and its total concentration was half that in plasma. In urine N-demethyldiazepam was mainly in the conjugated form. No hydroxylated metabolites of diazepam were found in plasma. Oxazepam was the metabolite found in bile and urine in the next highest concentration after N-demethyldiazepam. In the urine it was mainly conjugated, but in bile only a mean of 35% was conjugated. Both in bile and urine, N-methyloxazepam was found only intermittently and in low concentration. Diazepam and all of its common metabolites were measured in human bile, and the concentrations found were too low to produce a clinically significant enterohepatic circulation.     

The effects of repeated doses of clomipramine and alprazolam on physiological,psychomotor and cognitive functions in normal subjects

Summary The effects of a 10 day administration of clomipramine (25–50 mg t.i.d.), alprazolam (0.25–0.75 mg t.i.d.) and placebo were assessed in normal volunteers in a double-blind cross-over study. A battery of physiological, psychomotor and cognitive tests was administered both before and 3 h after drug on days 1, 5 and 10.The effects of alprazolam on EEG and evoked potentials were characteristic of benzodiazepines; clomipramine had little effect. In contrast, reaction speed was markedly slowed by clomipramine but little affected by alprazolam.Neither drug produced any accumulation of effect on a verbal recall task but neither did tolerance develop to the acute impairments produced by active treatments. Alprazolam produced an increase in levels of forgetting, especially on day 5. Subjective ratings for mood and bodily symptoms were adversely affected by clomipramine but little altered by alprazolam.It is suggested that some of the differences between drug treatments may be due to differences in the speed of onset of tolerance.     

Noise-induced sleep maintenance insomnia: hypnotic and residual effects of zaleplon

AIMS: The primary objective of the study was to assess the residual effects of zaleplon in the morning, 4 h after a middle-of-the-night administration. The secondary objective was to investigate the effectiveness of zaleplon in promoting sleep in healthy volunteers with noise-induced sleep maintenance insomnia. METHODS: Thirteen healthy male and female volunteers (aged 20-30 years) with normal hearing, who were sensitive to the sleep-disrupting effects of noise, participated in a double-blind, placebo- and active-drug controlled, four-period cross-over study. The subjects were permitted to sleep for 5 h (22.45-03.45 h) in a quiet environment before they were awoken. At 04.00 h they ingested 10 mg zaleplon, 20 mg zaleplon, 7.5 mg zopiclone (active control), or placebo before a second period of sleep (04.00-08.00 h), during which they were exposed to an 80 dB(A) 1 kHz pure tone pulse with an inter-tone interval of 1 s and a duration of 50 ms. The sound stimulus was stopped after 10 min of persistent sleep or after 2 h if the subject had not fallen asleep. Residual effects were assessed at 08.00 h (4 h after drug administration) using the digit symbol substitution test (DSST), choice reaction time (CRT), critical flicker fusion (CFF), and immediate and delayed free recall of a 20 word list. The data were analysed by analysis of variance. A Bonferroni adjustment was made for the three active treatments compared with placebo. RESULTS: There were no residual effects of zaleplon (10 and 20 mg) compared with placebo. Zopiclone impaired memory by delaying the free recall of words (P = 0.001) and attenuated performance on DSST (P = 0.004) and CRT (P = 0.001), compared with placebo. Zaleplon reduced the latency to persistent sleep (10 mg, P = 0.001; 20 mg, P = 0.014) and the 20 mg dose reduced stage 1 sleep (P = 0.012) compared with placebo. Zopiclone reduced stage 1 sleep (P = 0.001), increased stage 3 sleep (P = 0.0001) and increased total sleep time (P = 0.003), compared with placebo. CONCLUSIONS: Zaleplon (10 mg and 20 mg), administered in the middle of the night 4 h before arising, shortens sleep onset without impairing next-day performance.     

Pharmacokinetics of dipotassium chlorazepate in patients after repeated 50 mg oral doses

Dipotassium chlorazepate (DPC) was administered to ten patients (five males and five females), aged 18–37 years (mean 27.4), as a once daily dose of 50 mg until a steady state was reached. Plasma concentrations of the main metabolite N-desmethyldiazepam (DMD) were monitored by a high pressure liquid chromatographic (HPLC) method during the medication period and for 5 days after withdrawal of the drug. The plasma half life (t _1/2), the elimination coefficient (K), the steady state concentration , and the apparent volume of distribution (V), were calculated at steady state and the mean values ±SEM were 44±5 h, 0.0184±0.0026 h^-1, 1590±163 ng/ml and 1.41 ±0.17 l/kg, respectively. A moderate inter-individual variability was observed. There was no tendency towards dose dependent elimination.     

Pharmacokinetics of flunitrazepam following single- and multiple-dose oral administration to healthy human subjects

Healthy human subjects received single and multiple oral doses of flunitrazepam. Absorption and disposition were first order and reproducible from administration to administration. The oral doses were virtually completely available to the liver, and elimination from the body occurred entirely via metabolism. Assuming the liver to be the sole eliminating organ, hepatic blood clearance and extraction ratio were approximately 0.235 liter/hr/kg and 0.154, respectively. Steady-state blood volume of distribution averaged 3.76 liters/kg in the single-dose studies. Terminal exponential half-lives from the single- and multiple-dose studies (different subjects) averaged 13.5 and 19.2 hr, respectively, these differences were not due to clearance changes but were entirely attributable to variations in volumes of distribution.     

Being stoned: a review of self-reported cannabis effects

Although there has been considerable research into the adverse effects of cannabis, less attention has been directed toward subjective effects that may be associated with ongoing cannabis use. Examination of self-reported cannabis effects is an important issue in understanding the widespread use of cannabis. While reviews have identified euphoria as a primary factor in maintaining cannabis use, relaxation is the effect reported most commonly in naturalistic studies of cannabis users, irrespective of the method used. Self-reported effects in 12 naturalistic and 18 laboratory studies were compared. Regardless of methodology there was considerable variation in the effects experienced. Variation has been reported in terms of opposite effects being experienced by different individuals, variation of effects by individuals within a single occasion and between occasions of use. Factors that might explain this variation are outlined. Limitations of the available literature and suggested directions for future research are discussed. [Green B, Kavanagh D, Young R. Being stoned: a review of self-reported cannabis effects. Drug Alcohol Rev 2003;22:453 - 460]     

Adinazolam pharmacokinetics and behavioral effects following administration of 20–60 mg oral doses of its mesylate salt in healthy volunteers

The pharmacokinetics and pharmacodynamics of adinazolam were studied in 15 normal, healthy, non-obse volunteers. Placebo capsules and capsules containing 20, 40, and 60 mg adinazolam mesylate were administered as single oral doses in a randomized, 4-way crossover design. Plasma concentrations of adinazolam and mono-N-desmethyladinazolam (NDMAD) were determined by HPLC. Psychomotor performance and memory tests were performed and the degree of sedation assessed at designated times following drug administration. Adinazolam and NDMAD pharmacokinetics were linear throughout the dosage range studied. The ratio of NDMAD to adinazolam area under the curve was approximately 4:1. Dose-related decrements in psychomotor performance and memory were observed up to 8h after dosing (P<0.025 in all cases). Psychomotor performance decrements correlated more closely with NDMAD plasma concentrations than with adinazolam concentrations. These results suggest that NDMAD is responsible for a significant degree of the sedative and psychomotor effects observed after the administration of adinazolam.