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Biomedical subjects

I Hindmarch

Publications and source records attributed to I Hindmarch.

At least 145 records · Page 8Linked to original sources
PubMed1979

A preliminary study of the effects of prepeated doses of clobazam on aspects of performance, arousal and behaviour in a group of anxiety rated volunteers.

Repeated doses of a 1,5 benzodiazepine, clobazam, were administered to a group of consenting volunteers. Performance on a psychomotor performance task was not impaired by repeated doses of the drug. Subjective assessments of anxiety were reduced commensurate with an increase in the level of cortical integration, measured via critical flicker fusion thresholds, suggesting that the anxiolytic activity of the drug is related to its effect on arousal. Important differences were found between the responses of high and low anxiety subjects on objective measures of performance and arousal and on self-completion analogue rating scales.

Adult↗
PubMed1979

Effects of hypnotic and sleep-inducing drugs on objective assessments of human psychomotor performance and subjective appraisals of sleep and early morning behaviour.

1 An acute dose comparison against placebo of the effects of nitrazepam 5 mg and temazepam 15 and 30 mg on measures of arousal and performance and on subjective assessment of sleep was carried out in 20 subjects with a history of using night-time medication for insomnia. 2 Amylobarbitone (100 mg) was included as an active control and each drug was given in hard gelatin capsules. Subjects reported improved sleep with nitrazepam 5 mg and temazepam 30 mg, but there was evidence of impaired performance the next day with temazepam 30 mg. 3 The effect of temazepam 20 mg prepared in the Scherer formulation was compared against placebo in a further ten subjects. The subjects reported improved sleep without evidence of impaired performance the next day.

Adult↗
PubMed1979

Some aspects of the effects of clobazam on human psychomotor performance.

1 Three studies are described, the first being a comparison of the effects of acute night-time doses of clobazam 20 mg, amylobarbitone sodium 100 mg, nitrazepam 5 mg and placebo, on choice reaction time, critical flicker fusion (CFF) and stabilometer performance. Clobazam improved early morning performance on a choice reaction test, in contrast to the other two active drugs. 2 Repeated doses of clobazam 10 mg three times daily, chlordiazepoxide 10 mg three times daily and diazepam 5 mg three times daily were given for 5 days. Again clobazam did not produce any impairment of psychomotor performance, and noticeably increased CFF thresholds. 3 The effects of an acute night-time dose of clobazam 20 mg on psychomotor performance the morning after night-time medication were correlated with the neuroticism scores (on the EPI) of the subjects. Clobazam exerts a differential effect on psychomotor performance dependent on the basic personality trait. 4 Clobazam seems to differ significantly from the 1,4-benzodiazepines in that, although it reduces anxiety, it does so without any apparent impairment of psychomotor performance.

Adult↗
PubMed1979

The effects of repeated nocturnal doses of clobazam, dipotassium chlorazepate and placebo on subjective ratings of sleep and early morning behaviour and objective measures of arousal, psychomotor performance and anxiety.

1. Repeated nocturnal doses of 30 mg clobazam and dipotassium chlorazepate 15 mg showed no significant effects compared to matching placebo on tests of psychomotor performance and serial subtraction of numbers given in the morning and afternoon of the day following treatment. 2. Both active preparations improved the perceived quality of sleep compared to placebo. 3. A reduction in rated anxiety scores was found with clobazam on the afternoon of the day following treatment together with an elevation of critical flicker fusion thresholds. 4. Dipotassium chlorazepate was found to impair performance of a low level conceptual task but not to influence performance at a more difficult level.

Adult↗
PubMed1978

Factor analysis of a sleep evaluation questionnaire.

A self-completion sleep evaluation questionnaire (SEQ), consisting of 10 cm line analogue rating scale questions, was constructed to investigate subjects' responses to aspects of sleep and early morning behaviour. The questions were grouped into 4 chronological areas: the ease of getting to sleep (GTS), the perceived quality of sleep (QOS), the ease of awakening from sleep (AFS), and the integrity of early morning behaviour following wakefulness (BFW). Five hundred and one SEQs were completed during several investigations into the comparative effectiveness of hypnotic drugs. The classical factor analysis produced 4 factors which corresponded to the 4 aspects of sleep and early morning behaviour listed above. The GTS and QOS factors were positively correlated (+0.57), as were the AFS and BFW factors (+0.48). The 2 sleeping state factors (GTS and QOS) were orthogonal to the 2 waking state factors (AFS and BFW).

Adolescent↗
PubMed1978

A repeated dose comparison of the side effects of five antihistamines on objective assessments of psychomotor performance, central nervous system arousal and subjective appraisals of sleep and early morning behaviour.

The side effects of five antihistamines (chlorpheniramine maleate, mebhydrolin, clemastine hydrogen fumarate, Tavegil; ketotifen, and promethazine hydrochloride) were measured on subjective assessments of sleep and the integrity of early morning behaviour and objective assessments of complex psychomotor behaviour and central nervous system arousal. Fifty consenting volunteers each received one of the five preparations for a period of four days with the subjective effects being reported on a set of 10 cm line visual analogue scales and the objective assessments being made via a computer assisted reaction time task and critical flicker fusion thresholds. Chlorpheniramine, 4 mg t.d.s. for four days, produces a significant impairment in critical flicker fusion thresholds with respect to pretreatment baselines but none of the preparations showed any significant impairment in complex reaction time assessments. The subjective assessments of sleep and early morning hangover showed mebhydrolin and clemastine to be free from detrimental side effects, but promethazine and chlorpheniramine produce significant impairments in the integrity of early morning behaviour.

Adult↗
PubMed1978

Clobazam. A 1.5 benzodiazepine derivative: effects upon human psychomotor performance under different levels of task reinforcement.

Two dose levels of clobazam, a benzodiazepine derivative, were compared to placebo for their effects upon psychomotor performance in an acute dose daytime study with normals. An acute dose of 10 mg clobazam significantly reduced response latencies in the low reinforcement condition of a psychomotor performance task but not in the high reinforcement condition. However 20 mg clobazam did not produce any significant changes in performance under either low or high reinforcement. Response speed changes generally correlated positively with trait anziety and neuroticism scores at both doses of clobazam.

Adult↗
PubMed1978

The effect of a sub-chronic administration of three dose levels of a 1,5-benzodiazepine derivative, clobazam, on subjective assessments of sleep and aspects of psychomotor performance the morning following night time medication.

The effect of repeated doses of a 1,5-benzodiazepine derivative, clobazam, at doses of 20, 30, and 40 mg taken at night was assessed the morning following medication on a variety of subjective and objective measures of sleep and psychomotor performance. None of the three dose levels of the drug produced any significant changes in critical flicher fusion thresholds or in complex reaction time tasks. Conceptual learning ability was not impaired by any of the doses of clobazam administered. Clobazam was rated on a self-scoring analogue rating scale as an effective sleep inducer, which also improved the perceived quality of sleep. There was also a reduction in the perceived integrity of early morning behaviour commensurate with the reported ease of getting to sleep.

Adult↗
PubMed1978

The effects of repeated doses of temazepam taken in conjunction with alcohol on aspects of psychomotor performance the morning following night time medication.

A study to compare the morning-after effects of three dose levels of temazepam (Euhypnos capsules) given with alcohol, was carried out in 18 healthy volunteers. Matched placebos were given for two days before and four days after the four nights on active drug and a standard dose of alcohol was given on all ten nights of the study. Objective measurements made on the mornings after days 2, 4, 6 and 10 were critical flicker fusion threshold (CFF), choice reaction time (CRT) and digit symbol substitution tasks (DSST). The administration of 10 or 20 mg temazepam with alcohol produced no significant change inany of these measurements. 30 mg produced no change in DSST and although there was some impairment of CRT at this dose, it was not statistically significant. The combination of 30 mg temazepam and alcohol significantly depressed CFF following four nights on these drugs.

Adult↗
PubMed1977

A repeated dose comparison of dichloralphenazone, flunitrazepam and amylobarbitone sodium on some aspects of sleep and early morning behaviour in normal subjects.

1 Seven normal subjects were given three different hypnotics (flunitrazepam 1 mg, amylobarbitone sodium 100 mg and dichloralphenazone 1300 mg) for four consecutive nights each. 2 All three substances improved subjective assessment of the ease of getting to sleep. Flunitrazepam was rated as better than eithr dichloralphenazone or amylobarbitone sodium in this respect. 3 The perceived quality of induced sleep was not altered by any of the preparations. 4 There was a disturbance of the subjective ratings of getting to sleep following cessation of treatment with dichloralphenazone, giving tentative support to the existence of a 'rebound' effect. 5 Dichloralphenazone produced an impairment in psychomotor performance as measured on a complex reaction time test following four nights medication with the drug.

Adolescent↗
PubMed1977

Clobazam, a 1,5-benzodiazepine, and car-driving ability.

1 The effects of clobazam, a new anxiolytic agent (a 1,5-benzodiazepine) on car-driving ability and other tests of psychomotor performance were investigated in a double-blind, cross-over study v. placebo in normal volunteers. 2 Clobazam (20 mg) or placebo was given nightly for six nights to ten volunteers and subjective ratings of sleep and subjective and objective assessments of behaviour and psychomotor performance on the morning following drug ingestion were recorded. 3 Clobazam significantly improved the subjective ratings of sleep induction and quality of induced sleep. 4 Clobazam did not significantly impair performance in a variety of psychomotor tests and car-driving ability. 5 The validity of the measures used and the relevance of the findings to real life car-driving situations are discussed.

Adult↗
PubMed1977

Repeated dose comparison of nomifensine, imipramine and placebo on subjective assessments of sleep and objective measures of psychomotor performance.

1. Nine normal subjects volunteered to participate in a randomized single-blind crossover study of nomifensine 75 mg and two comparators, imipramine 75 mg and placebo. 2. Each volunteer received placebo for 3 d, then the first test drug for 4 days. This sequence was repeated twice more, so that each subject received each comparator. All medication was taken three times daily. 3. Assessments were made on days 3, 5 and 7 of each sequence, and consisted of a Sleep Evaluation Questionnaire, a test of Critical Flicker Fusion and a measure of Complex Reaction Time (CRT). 4. There were no significant differences in the CRT. There was a significant increase in critical flicker fusion with nomifensine. 5. Although both nomifensine and imipramine disturbed the quality of sleep, only imipramine produced a hangover.

Adult↗
PubMed1977

Laboratory investigation of effect of acute doses of nomifensine on a simulated aspect of night-time car driving performance.

1. Six healthy volunteers received single doses of either nomifensine 100 mg, nomifensine 50 mg or placebo at weekly intervals in a randomized double-blind crossover study. 2. Subjects were subjected to a simulated test of car driving at night. 3. Testing lasted about 1.5 h and consisted of measuring responses to light stimuli, a modification of a test designed by Baker & Theologus (1972). 4. Nomifensine 100 mg reduced the latency of response significantly when compared with placebo (P less than 0.05). Nomifensine 50 mg had no significant effect. 5. It was concluded that nomifensine was unlikely to impair night driving performance.

Adult↗
PubMed1977

A repeated dose comparison of three benzodiazepine derivative (nitrazepam, flurazepam and flunitrazepam) on subjective appraisals of sleep and measures of psychomotor performance the morning following night-time medication.

Repeated doses of 5 mg nitrazepam, 15 mg flurazepam, and 1 mg flunitrazepam improved subjective assessments of the ease of getting to sleep and the perceived quality of induced sleep in a population of 30 healthy volunteers. The subjective reports of improved sleep inducement were related to a perceived difficulty in awakening from sleep the morning following medication. This subjectively reported "hangover" is also shown in the impairment of mental arithmetic abilities as measured on the serial subtraction of sevens technique. However, complex psychomotor performance is unaffected by repeated administration of these three benzodiazepine derivatives, although these later results are somewhat equivocal. Evidence of a "rebound phenomenon" following 4 nights' withdrawal of active medication is shown in both subjective and objective measures of sleep and early morning behaviour.

Adult↗
PubMed1976

The effects of the sub-chronic administration of an anti-histamine, clemastine, on tests of car driving ability and psychomotor performance.

A double-blind placebo-controlled crossover trial was carried out in 21 normal volunteers to study the effects of sub-chronic administration of clemastine on car driving ability and psychomotor performance. Subjects were assessed on 5 tests representing various aspects of everyday car driving experience, and on subjective rating scales for mood, sleep, and psychomotor integration. The results showed that repeated doses of 1 mg clemastine b.d. for 3 days had no significant consistent effect on any of the parameters measured.

Automobile Driving↗
PubMed1976

A sub-chronic study of the subjective quality of sleep and psychological measures of performance on the morning following night time medication with temazepam.

A sub-chronic study of 7-chloro-2,3-dihydro-3-hydroxy-1-methyl-5-phenyl-1H-1,4-benzodiazepin-2-one (temazepam, Euhypnos) at three dose levels was carried out in 30 healthy volunteers. A matching placebo was given before and after the 4 nights of active compound. The subjective response was measured by means of a sleep evaluation questionnaire, and the objective measurements used were the critical flicker fusion threshold and choice reaction time. A clear dose-response relationship was seen in the subjective and objective measurements with the three doses used. A rebound phenomenon was seen only at the high dose levels in two subjective measures, viz. getting to sleep and behaviour following waking.

Adult↗