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Biomedical subjects

I Hindmarch

Publications and source records attributed to I Hindmarch.

At least 109 records · Page 6Linked to original sources
PubMed1987

Comparison of recovery after halothane or alfentanil anaesthesia for minor surgery.

Recovery after anaesthesia was assessed using the Maddox Wing Test (MW), Critical Flicker Fusion Threshold (CFF), Choice Reaction Time (CRT), Line Analogue Rating Scales (LARS), a Tracking Test and a test of Semantic Memory in 44 patients who had undergone minor gynaecological surgery. The patients were allocated randomly to one of two groups and received either methohexitone, nitrous oxide, oxygen and halothane or methohexitone, alfentanil, nitrous oxide and oxygen. Immediate recovery was more rapid in the alfentanil group (P less than 0.01), but apnoea (P less than 0.05) and hiccups (P less than 0.05) were more common. Except for the CFF test, which showed the alfentanil patients to be less sedated than the halothane patients on the morning after anaesthesia (P less than 0.05), the results of the tests were similar in both groups and showed, initially, substantial impairment of psychomotor functions which gradually returned to baseline values. This comparison with halothane anaesthesia indicates that a technique using methohexitone and alfentanil is suitable for day-case surgery.

Adult↗
PubMed1987

Psychomotor effects of astemizole and chlorpheniramine, alone and in combination with alcohol.

Road traffic accidents are a leading cause of mortality and morbidity, and their association with alcohol and drugs such as minor tranquillizers is well established (Seppala et al., 1979). There is also epidemiological evidence to associate the older, sedative antihistamines with motorcycle accidents (Skegg et al., 1979). Astemizole is a recently introduced H1-antagonist which, unlike older antihistamines, does not cause central nervous system sedation. The present study was designed to compare the effects of astemizole and chlorpheniramine, alone and in combination with alcohol, on an objective measure of psychomotor performance relating to car-driving ability.

Adult↗
PubMed1987

Vinpocetine effects on cognitive impairments produced by flunitrazepam.

The effects of pre-treatment with vinpocetine 40 mg, on flunitrazepam-induced impairment of memory, were studied in 8 normal volunteers. Tests of Critical Flicker Fusion Threshold, a Sternberg Memory Scanning Task, along with subjective ratings of drug action were used. Drug effects were found to be modest. Treatment with vinpocetine was associated with improvements in short-term memory processes.

Adult↗
PubMed1986

[Activity of Ginkgo biloba extract on short-term memory].

Eight healthy female volunteers were included in a double-blind, cross-over trial comparing Ginkgo biloba extract in acute and ascending doses (120, 240, 600 mg) with a placebo. One hour after treatment they were subjected to a battery of tests, including: critical flicker fusion, choice reaction time, subjective rating scale and Sternberg memory scanning test. No statistically significant differences with the placebo were observed in the first three tests. In contrast, short term memory, as assessed by the Sternberg technique, was very significantly improved following 600 mg of Ginkgo biloba extract, as compared with the placebo. These results differentiate Ginkgo biloba extract from sedative and stimulant drugs and suggest a specific effect on memory processes.

Adult↗
PubMed1986

Alprazolam and lorazepam single and multiple-dose effects on psychomotor skills and sleep.

The effects of alprazolam 0.5 mg and lorazepam 2 mg on cognitive and psychomotor skills were assessed in twelve normal volunteer subjects in a randomised, double-blind, crossover design. Single and multiple dose effects were monitored using a battery of tests comprising critical flicker fusion threshold (CFFT), choice reaction time (CRT), simulated car tracking, and subjective ratings of perceived sedation (LARS) and of sleep behaviour (LSEQ). Compared with placebo baseline scores, treatment with lorazepam 2 mg (both single and multiple doses) resulted in a widespread impairment of CRT, tracking accuracy, and CFFT. Single doses of alprazolam 0.5 mg reduced CFFT with respect to the placebo baseline. Single and multiple dose treatment with both drugs resulted in subjective reports of sedation, a reduction of sleep onset latency, and improved sleep quality. Only lorazepam 2 mg significantly disrupted the integrity of behaviour on waking from sleep. These results suggest important pharmacodynamic differences between the two drugs in the doses used.

Adult↗
PubMed1986

Psychopharmacological aspects of idiopathic and transient insomnia.

Residual sedative effects seem to be intrinsic properties of effective hypnotic agents. Residual effects are dose related and more likely if the elimination half-life is greater than 12 hours. In two separate studies, investigations into effects on performance were carried out using a series of psychometric tests. In the first, a group of skilled radar operators working a shift system were given a pre-sleep administration of temazepam 20 mg and measurements were made of any residual effects. In the second clinical study, general practice patients suffering from idiopathic insomnia were randomized onto either temazepam 20 mg, triazolam 0.25 mg, nitrazepam 5 mg, flurazepam 15 mg, or placebo. Assessments were made using the Leeds Psychomotor Tester to measure Choice Reaction Time and Critical Flicker Fusion. In a separate test, digit substitution was used to measure sensory processing ability. In addition, the Leeds Sleep Evaluation Questionnaire was completed by each patient in the clinical study to provide a subjective evaluation of ease of getting to sleep, ease of awakening and behaviour after awakening. Neither study showed a residual activity that was likely to impair performance following temazepam 20 mg indicating the usefulness of this drug in the management of idiopathic insomnia and sleep difficulties introduced by changes in scheduling of sleep, i.e. intercontinental travel or shift work.

Adult↗
PubMed1986

A placebo-controlled assessment of mequitazine and astemizole in tests of psychomotor ability.

This study was a single and repeated dose comparison of mequitazine 5 mg, astemizole 10 mg and placebo and their effects on CNS activity, psychomotor performance and subjective appraisals of alertness. Nine Caucasian female volunteers aged between 29 and 40 years, declared healthy following a medical examination and who showed sensitivity to antihistamine sedation, were admitted to the study. Subjects were allocated to treatment in a randomized block design by which each subject received single and repeat doses of mequitazine 5 mg, astemizole 10 mg and placebo under double-blind conditions. Objective assessments (choice reaction time, critical flicker fusion threshold, simulated car tracking task, Stroop test) and subjective assessments (sedation and sleep rating scales, adverse effects and event recording) were made. Assessments were performed on day 1 and day 8 at pre-dosing (0 h) and at 1.5, 3.5 and 5.5 h following drug administration. Choice reaction times were dissimilar 5.5 h post-drug administration, the mequitazine group having a reaction time comparable to baseline and faster than the astemizole and placebo treatment groups. However, none of the treatments produced any significant or consistent effects when assessed on objective and subjective measures of performance, critical flicker fusion threshold, sedation and sleep and there were no treatment differences in the nature and number of adverse effects reported.

Adult↗
PubMed1985

Psychopharmacological effects of vinpocetine in normal healthy volunteers.

Twelve healthy female volunteers received pre-treatments with vinpocetine 10, 20, 40 mg and placebo (t.d.s.) for two days according to a randomised, double-blind crossover design. On the third day of treatment and 1 h following morning dosage, subjects completed a battery of psychological tests including Critical Flicker Fusion (CFF), Choice Reaction Time (CRT), Subjective Ratings of Drug Effects (LARS) and a Sternberg Memory Scanning Test. No statistically significant changes from placebo were observed on CFF, CRT or subjective ratings of drug effects. However, memory as assessed using the Sternberg technique was found to be significantly improved following treatment with vinpocetine 40 mg when compared to placebo and results suggested a localised effect of the drug on the serial comparison stage of the reaction process.

Adult↗
PubMed1985

Residual effects of zopiclone and benzodiazepine hypnotics on psychomotor performance related to car driving.

A double-blind, randomized, cross-over study was carried out in 10 normal healthy volunteers to investigate the residual effects of 7.5 mg zopiclone, 1 mg lormetazepam, 0.25 mg triazolam, 1 mg flunitrazepam and placebo. Tests of psychomotor performance and analogues of car driving ability were administered the morning following night-time medication. Changes with respect to placebo in an information-processing task one hour after taking the medications confirmed the hypnotic efficacy of zopiclone, triazolam and flunitrazepam. Flunitrazepam also produced a significant depression of the Critical Flicker Fusion Threshold (CFF) and increased subjective ratings of sedation one hour after nocturnal dosing. Flunitrazepam impaired the reaction time on the information-processing test the morning following doses of 1 mg.

Adult↗
PubMed1984

Psychological performance models as indicators of the effects of hypnotic drugs on sleep.

A theoretical and practical scheme for the measurement of change in psychological performance is presented. An information processing paradigm is used as the basis for the model while personality, memory, motivational and experiential variables are shown to be amenable to control via the application of standard experimental methodologies. The model is realised in practical experimental terms in the use of measures of choice reaction time and critical flicker fusion threshold. The reliability and sensitivity of these parsimonious indices of performance change is illustrated in a brief review of the effects of benzodiazepine hypnotics on early morning performance.

Humans↗
PubMed1984

Effects of zopiclone and benzodiazepine hypnotics on search in short-term memory.

The effects of zopiclone 7.5 mg in comparison to flunitrazepam 1 mg, triazolam 0.25 mg and lormetazepam 1 mg on stages of information processing in a memory-scanning task were investigated in 10 normal volunteers using a double-blind placebo-controlled cross-over design. Overall reaction times for the test were significantly increased 1 h following treatment with zopiclone, flunitrazepam and triazolam and in the morning following nighttime medication with flunitrazepam. The effects of zopiclone, flunitrazepam and triazolam were found to be located in the serial comparison and response-selection organization stages of the reaction process although both flunitrazepam and triazolam caused additional impairment of stimulus encoding.

Adult↗
PubMed1984

The psychopharmacological effects of Ginkgo biloba extract in normal healthy volunteers.

Eight healthy female volunteers received Ginkgo biloba extract (G.B.E.) 120, 240, 600 mg and placebo according to a randomized, double-blind crossover design. One hour following treatment, subjects completed a battery of psychological tests including critical flicker fusion (CFF), choice reaction time (CRT), subjective ratings of drug effects (LARS) and a Sternberg memory scanning test. No statistically significant changes from placebo were observed on CFF, CRT or subjective ratings of drug effects. However, memory as assessed using the Sternberg technique was found to be significantly improved following treatment with G.B.E. 600 mg when compared to placebo and results suggested a localized effect of the drug on the serial comparison stage of the reaction process.

Adult↗
PubMed1983

The effects of lormetazepam on aspects of sleep and early morning performance.

Lormetazepam in a dose range 0.5-2.0 mg was given on a repeated dose regimen to a group of 12 healthy female volunteers in a double blind crossover design with each subject acting as her own control and receiving all 3 drug treatment conditions. There were no consistent or persistent effects noticed with 0.5 mg lormetazepam on tests of psychomotor function, performance and analogue rating scales for sleep and early morning behaviour. Lormetazepam 1 mg produced no significant effects on objective (CFF) or subjective measures (ARS) of sedation the morning following either acute or repeated dosing and had no effects on subjective ratings of sleep and early morning behaviour. Digit symbol substitution was impaired following acute doses of lormetazepam 1 mg. Evidence of a significant residual sedative effect was found on CFF and ARS ratings only after acute dosing with lormetazepam 2 mg. These sedative sequelae were not found after repeated doses of lormetazepam 2 mg although DSST scores were impaired. Lormetazepam 2 mg significantly improved sleep induction and sleep quality scores without impairing the ease of waking and the integrity of early morning behaviour. Lormetazepam 1 mg shows no residual sedative effect as measured by CFF and ARS, the morning following either acute or repeated doses.

Adult↗