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Biomedical subjects

I Hindmarch

Publications and source records attributed to I Hindmarch.

At least 73 records · Page 4Linked to original sources
PubMed1992

Behavioural toxicity of antidepressants with particular reference to moclobemide.

The clinical decision to use a particular antidepressant should be made with reference to the behavioural toxicity profiles of substances in current use. Antidepressants can be cardiotoxic, proconvulsant, able to cause weight gain and sleep disturbance, and also impair psychological functions necessary for everyday living. Behavioural toxicity (reduction in psychomotor activity or cognitive ability) tends to augment levels of psychomotor and cognitive retardation; meta-analysis of controlled studies of antidepressants shows that some tricyclics can disrupt these functions. In comparison with these, moclobemide is relatively free from significant behavioural toxicity within the dose-ranges used. No relevant differences were found between placebo and 200 mg moclobemide on a battery of psychomotor and cognitive tests: with 400 mg, there was a significant impairment of peripheral reaction time, but no other measure of the test battery was impaired. In comparison, amitriptyline 50 mg, produced a noticeable and significant impairment of psychomotor and cognitive skills on most test measures. On the whole moclobemide has been found to be free from any behavioural toxicity likely to interfere with the well-being of patients or their performance of the tasks of everyday living.

Animals↗
PubMed1992

Psychomotor performance in smokers following single and repeated doses of nicotine gum.

The psychomotor effects of single and repeated doses of 2 mg nicotine gum were investigated in 13 regular smokers who had abstained from tobacco overnight. In comparison to baseline, a first dose of nicotine led to significantly raised critical flicker fusion thresholds, faster motor reaction times, improved compensatory tracking performance, and faster short-term memory reaction times. Performance after a second and third dose of nicotine remained significantly improved on all measures in comparison to baseline, and absolutely improved when comparing first and third nicotine doses on measures of sensorimotor performance. Throughout, comparisons with a placebo gum condition confirmed that these effects were genuine and not subject to the development of acute nicotine tolerance, suggesting that the enhancement of psychomotor performance experienced by smokers after a first cigarette may be maintained by repeated smoking.

Administration, Oral↗
PubMed1992

The effects of acute and repeated doses of zolpidem on subjective sleep, psychomotor performance and cognitive function in elderly volunteers.

We gave 24 healthy elderly volunteers with a perceived sleep onset of at least 30 minutes zolpidem 5 mg, zolpidem 10 mg, or placebo for 7 days in a double-blind, three-way, crossover study. The morning after nocturnal dosing, psychomotor performance and cognitive ability were measured using tests which are sensitive to the residual effects of hypnotics and to the effects of drugs on various indicators of sleep quality. The tests were: Choice Reaction Time; Tracking; Critical Flicker Fusion Threshold; Memory Scanning; Word Recognition; the Leeds Sleep Evaluation Questionnaire and Line Analogue Rating Scales. Zolpidem produced a subjective improvement in sleep but did not impair performance the following day. Furthermore, during repeated administration, there was no tolerance to the effects of sleep latency and quality of sleep, nor adverse effects on task performance.

Aged↗
PubMed1992

A review of the psychomotor effects of paroxetine.

Studies on the behavioural effects of paroxetine on healthy young volunteers, elderly volunteers, and patients suffering from major depressive illness failed to show any evidence of detrimental effects on a battery of objective and subjective measures even when alcohol was taken. In contrast, the chosen verum, amitriptyline or lorazepam, produced significant impairment. The study on depressed patients showed improvement in cognitive functions among the paroxetine group from the start, whereas these functions were, initially, significantly impaired in the dothiepin group. Moreover, the Leeds Sleep Evaluation Questionnaire indicated that dothiepin produced, with respect to paroxetine, a significantly poorer quality of sleep.

Adult↗
PubMed1992

The effects of acute and repeated doses of suriclone on subjective sleep, psychomotor performance and cognitive function in young and elderly volunteers.

Suriclone is a new anxiolytic drug belonging to the family of cyclopyrrolones. The effects of acute and repeated doses of suriclone on subjective sleep, psychomotor performance and cognitive function were compared to those of placebo in young and elderly volunteers. Young volunteers randomly received suriclone 0.2 mg, 0.3 mg, 0.4 mg or placebo tid, and the elderly received suriclone 0.1 mg, 0.2 mg or placebo tid. After the first single dose and after a three-day treatment, subjects completed at 1, 2, 4, 12 and 24 h after drug administration the following battery of psychomotor and cognitive tests: critical flicker fusion threshold, choice reaction time, simulated car tracking test, the stroop test and the Sternberg memory scanning task. Visual analogue scales and the Leeds sleep evaluation questionnaire were also administered during the study. No significant effects of suriclone compared to placebo were seen on the psychomotor tests both in young and elderly volunteers. The only significant result was an improvement of the ease of getting to sleep in the young with 0.4 mg suriclone tid. In conclusion, there is little evidence to suggest that suriclone produces any measurable behavioural toxicity, so often seen with many of the benzodiazepines, in either young or elderly subjects.

Adult↗
PubMed1992

The effects of paroxetine, alone and in combination with alcohol on psychomotor performance and cognitive function in the elderly.

Fifteen healthy male volunteers aged over 60 years received acute and repeated doses of paroxetine 20 mg or placebo, and acute doses of lorazepam 1 mg (as a positive internal control) with or without alcohol (0.6 g/kg of body weight) administered openly in a double blind balanced crossover study in which each subject acted as his own control. Psychomotor performance and cognitive function were assessed using a test battery which included critical flicker fusion, choice reaction time, compensatory tracking, Stroop and memory scanning tests. Subjective ratings of mood and sleep were recorded using line analogue rating scales. The pattern of results indicated that paroxetine had little or no effect on most of the test variables, and in some instances (critical flicker fusion thresholds) improved information processing ability. This was in marked contrast to the lorazepam verum which produced sedation and disruption of performance. Paroxetine had a slight antagonistic effect on alcohol induced sedation whereas impairment of performance with lorazepam was potentiated by co-administration of alcohol. The low behavioural toxicity of paroxetine in elderly volunteers has important implications for the pharmacotherapy of depression.

Aged↗
PubMed1991

Separate and combined effects of the social drugs on psychomotor performance.

Ten female subjects (five smokers and five non-smokers) performed a choice reaction time task (CRT), a compensatory tracking task (CTT), a short-term memory task (STM) and were tested for their critical flicker fusion threshold (CFF) at set points over 4 h after the administration of each possible combination of nicotine (2 mg gum or placebo), caffeine (250 mg capsule or placebo) and alcohol (30 g or placebo). Memory and motor function were shown to be facilitated by nicotine or caffeine, and the debilitating effects of alcohol were frequently antagonised by either drug. In spite of the differences in their neuropharmacological actions, combinations of nicotine, caffeine and alcohol may be compared through their effects on common information processing mechanisms involved in psychomotor performance.

Adult↗
PubMed1991

Efficacy and tolerance of vinpocetine in ambulant patients suffering from mild to moderate organic psychosyndromes.

The efficacy and tolerance of orally administered vinpocetine was investigated in patients suffering from mild to moderate organic psychosyndromes including primary dementia. Two hundred and three patients were included in a placebo-controlled, randomized double-blind, multicentre trial and received every day for 16 weeks either: 3 x 10 mg doses of vinpocetine, 3 x 20 mg doses of vinpocetine, or 3 x placebo. Patients were assessed on ratings of clinical global impression, cognitive performance and on measures of the quality of life including depressive illness. There were no clinically relevant side-effects reported and the frequencies of adverse events between patients treated with vinpocetine (30 mg or 60 mg) and placebo were comparable. Statistically significant improvements were found in favour of both active treatment groups compared to placebo in both confirmatory evaluations of efficacy of treatment: the "Global Improvement" (on the CGI scale) and cognitive performance (SKT). Vinpocetine was also superior to placebo in ratings of the "severity of illness". This study demonstrates the usefulness and efficacy of vinpocetine in the management of patients with moderate organic psychosyndromes. An apparently greater therapeutic efficacy of 3 x 10 mg vinpocetine compared with the higher vinpocetine dosage is statistically not significant.

Aged↗
PubMed1991

Pharmacodynamic effects of buspirone and clobazam.

1. The pharmacodynamic effects of buspirone and clobazam were compared in two volunteer studies. Acute doses of buspirone 5 mg, 10 mg and clobazam 10 mg were contrasted with placebo and a verum (lorazepam 1 mg), in a repeated measures design with 10 subjects assessed on a battery of psychometric tests at 1.5, 3.5, and 5.5 h post dose. For the combined results clobazam and the lower dose of buspirone (5 mg) were significantly contrasted with lorazepam on measures of subjective sedation, memory and choice reaction time (CRT). The higher dose of buspirone was not statistically different from lorazepam for all measures except memory; whilst contrasting significantly with placebo and clobazam on movement and total reaction time components respectively. Though failing to achieve significance, a similar trend was seen for critical flicker fusion (CFF) with buspirone 10 mg and lorazepam producing the lowest scores indicative of increased sedation. 2. Repeated doses of buspirone 5 mg twice daily, clobazam 10 mg twice daily, or placebo twice daily for 8 consecutive days were compared on the same battery of psychometric tests in a repeated measures design. Nine subjects were assessed on days 1, 3, and 8 of the study. Overall, memory performance significantly decreased with buspirone 5 mg in contrast to both clobazam and placebo whilst the opposite trend was seen with CFF. Clobazam significantly improved TRT in contrast to both placebo and buspirone. 3. These results indicate improved reaction time and memory performance with repeated dosing of clobazam in contrast to buspirone. Impairment following acute administration of buspirone appears limited to the higher (10 mg) dose.

Adult↗
PubMed1991

Effects of topical administration of levocabastine on psychomotor and cognitive function.

The possible central nervous system effects of topical administration of levocabastine, a new H1-antagonist, were investigated in a double-blind, placebo-controlled, crossover study using a battery of objective and subjective tests. These were carried out in 12 volunteers up to five hours postapplication. Neither the recommended (0.5 mg/mL) nor the four times higher (2.0 mg/mL) concentration level was found to be distinguishable from placebo, while the verum (triprolidine 10 mg) was significantly worse, on both objective and subjective measures.

Administration, Topical↗
PubMed1991

The effects of alcohol and other drugs on psychomotor performance and cognitive function.

The effects of four doses of alcohol (0.25 g/kg-1 g/kg) and placebo on a standard test battery of cognitive and psychomotor performance are described. The tests included critical flicker fusion threshold, choice reaction time, tracking and memory scanning. The results of this experiment are compared with those of a number of similar studies which examined the effects of other psychoactive substances. Using relative effect sizes, the behavioural toxicity of alcohol is compared with the effects of these other drugs on psychomotor performance and cognitive function.

Adult↗
PubMed1991

Residual effects of hypnotics: an update.

The sedative/hypnotic benzodiazepines introduced worldwide in the early 1960s were acclaimed for their low chemical toxicity and safety in clinical use. A decade later, some researchers and clinicians found that while all the drugs had undoubted potency and efficacy as sleep inducers and maintainers, the trade-off in residual effects (e.g., excessive daytime tiredness, poor concentration, impaired psychomotor performance, lowered mental abilities) was cause for concern. These sequelae not only affected patients' safety and ability to perform daytime tasks, but were also counter-therapeutic; the daytime sleep that was produced interfered with the natural nocturnal sleep. In a recent study, the degree to which patient abilities were impaired was measured by a number of psychomotor tests. Benzodiazepines with a duration of clinical effect of less than 8 to 10 hours produced fewer, less frequent residual effects than those with a measurable activity in excess of the normal nocturnal sleep period.

Benzodiazepines↗
PubMed1990

Effects of nicotine gum on psychomotor performance in smokers and non-smokers.

Two experiments were conducted to investigate the effects of nicotine on human performance. In the first study six smokers, who had been allowed to smoke normally prior to testing, completed a battery of psychometric tests (choice reaction time, memory scanning, tracking and flicker fusion threshold) at set points over 4 h after chewing 0, 2, or 4 mg nicotine polacrilex gum. A second study followed a similar design, but used five non-smoker volunteers who were required to chew only the 0 or 2 mg nicotine gum. Blood nicotine levels following the gum were measured in all subjects. The results indicate that additional nicotine improved both the speed and accuracy of motor activity among the smokers, but did not enhance central cognitive processes. No drug effects were found in the non-smoker study.

Chewing Gum↗
PubMed1990

Alpidem and psychological performance in elderly subjects.

With increasing age there is a concurrent increase in the side effects following psychotropic medication. The necessity of measuring the magnitude of the extent of the side effects using a properly constructed psychometric test battery is illustrated with reference to a dose ranging study compared to acute dose effects of 25, 50 and 100 mg alpidem in a population of elderly volunteers. The study was both placebo and verum (lorazepam 2 mg) controlled and the treatments were administered according to a crossover design with each subject acting as their own control. The effects of the verum were evident on all the tests and under these conditions there was no effect on psychological differences following doses of 25 and 50 mg alpidem. There was an initial deterioration one hour after dosing following 100 mg alpidem which was readily attenuated by three hours. No differences with any of the doses of alpidem were able to be detected at any other time point even though the verum continued to show the sensitivity of the battery to tests to sedative amnestic sensori-motor and information processing activities.

Aged↗
PubMed1990

Immediate and overnight effects of zopiclone 7.5 mg and nitrazepam 5 mg with ethanol, on psychomotor performance and memory in healthy volunteers.

The effects of ethanol (0.2-0.4 g/kg) taken in conjunction with a single nocturnal dose of zopiclone 7.5 mg or nitrazepam 5 mg, on the early morning performance were investigated by means of psychomotor tests in 9 female volunteers. While there was no noticeable difference in the Choice Reaction Time (CRT) for any of the drug-ethanol combinations and ethanol alone, the zopiclone combination appeared to be initially more sedative in the Critical Flicker Fusion test (CFF). Both drug combinations impaired short-term memory and induced retrograde amnesia to the same extent, although only the nitrazepam-ethanol treatment caused further anterograde amnesia as compared to ethanol alone. Finally, both drug-ethanol combinations exhibited equivalent hypnotic properties as assessed by the Leeds Sleep Evaluation Questionnaire (LSEQ) without any more residual effects than with ethanol alone. These results suggest neither zopiclone, nor nitrazepam potentiate the effects of ethanol at the doses used.

Adolescent↗
PubMed1990

A comparison of the efficacy, tolerance and residual effects of zopiclone, flurazepam and placebo in insomniac outpatients.

A double-blind randomized parallel group design was used to compare the tolerance and efficacy of zopiclone 7.5 mg, flurazepam 30 mg and placebo taken each night for 3 weeks in a group of 24 out-patients complaining of sleep disturbance. Analogue rating scales were used to assess the efficacy of the treatments while tolerance and residual effects were measured weekly using a battery of performance tests (Critical Flicker Fusion Threshold, Choice Reaction Time, Letter Cancellation and Digit Span). Physical and clinical examinations, including ECG and EEG, were conducted before and after the experimental period and spontaneously reported side-effects were recorded. Analysis of variance on 24 completed cases (8 patients in each treatment group) showed both active treatments to be significantly better than placebo in shortening sleep onset latency. Flurazepam increased the duration of sleep and produced a "hangover" of impaired psychomotor function. Zopiclone had no observable effect on early morning performance and was free from residual sedative activity. The lack of residual effects with zopiclone 7.5 mg, at a dose shown to be clinically effective, suggests its use in ambulant or out-patient populations where daytime sedation could interfere with every day activities.

Adolescent↗