PubMed HealthSearch

Biomedical subjects

C H Ashton

Publications and source records attributed to C H Ashton.

17 recordsLinked to original sources

Absence of withdrawal effects of ritanserin following chronic dosing in healthy volunteers.

The possible development of withdrawal symptoms following abrupt discontinuation of ritanserin after chronic administration of 10 mg daily for 8 weeks was investigated in a placebo controlled trial in 40 healthy subjects. The study consisted of two phases. In the first phase, under single blind conditions, all subjects received placebo for 2 weeks followed by a single daily dose of ritanserin (10 mg) for 8 weeks. In the second phase, under double blind conditions, subjects were randomised to receive either placebo or to continue on ritanserin (10 mg) for a further 4 weeks. Psychological assessments were performed at the start of and at intervals throughout the study. Levels of anxiety, concentration, quality of sleep and morning vigilance were measured throughout by daily visual analogue scales. No significant changes were detected in any of the measures in the group of subjects who received ritanserin compared to the group who received placebo during the second phase of the study. Ritanserin discontinuation following chronic dosing in healthy volunteers does not appear to be associated with withdrawal symptoms.

Adolescent

Long term use of transcutaneous electrical nerve stimulation at Newcastle Pain Relief Clinic.

This retrospective study of long-term use of transcutaneous electrical nerve stimulation (TENS) at Newcastle Pain Relief Clinic indicates that TENS has been a successful analgesic treatment for 58.6% of 1582 patients attending the clinic over a period of 10 years. A wide range of pain conditions were found to respond to TENS and many patients continued to use the treatment for several years. Most patients not responding to TENS (during a home trial) returned stimulators at the first follow-up appointment. Thus TENS should be considered as a simple, safe and reusable first line treatment for many pain conditions.

Ambulatory Care Facilities

Analgesic effects of different pulse patterns of transcutaneous electrical nerve stimulation on cold-induced pain in normal subjects.

The analgesic efficacy of various pulse patterns of transcutaneous electrical nerve stimulation (TENS) were assessed in 84 normal healthy subjects using the cold pressor pain technique. Burst, modulation, random and continuous TENS all significantly elevated ice pain threshold. Continuous (80 Hz) TENS produced the greatest mean elevation in threshold but the response to random TENS showed the least inter-subject variation. Ice pain tolerance was increased by all modes of TENS, continuous TENS producing the greatest magnitude of response, although these changes did not reach statistical significance. Increasing the size of electrodes reduced the effect of continuous TENS. The clinical implications of these findings are discussed.

Adolescent

An in-depth study of long-term users of transcutaneous electrical nerve stimulation (TENS). Implications for clinical use of TENS.

This in-depth study examines the relationships between patient, stimulator and outcome variables in a large number of chronic pain patients utilising TENS on a long-term basis. 179 patients completed a TENS questionnaire designed to record age, sex, cause and site of pain and TENS treatment regime. Of these 179 patients, 107 attended our research unit for assessment of the electrical characteristics of TENS during self-administered treatment. Although a remarkable lack of correlation between patient, stimulator and outcome variables was found to exist, the analysis revealed much information of importance: 47% of patients found TENS reduced their pain by more than half; TENS analgesia was rapid both in onset (less than 0.5 h in 75% patients) and in offset (less than 0.5 h in 51% patients); one-third of patients utilised TENS for over 61 h/week; pulse frequencies between 1 and 70 Hz were utilised by 75% of patients; 44% of patients benefitted from burst mode stimulation. The clinical implications of these findings are discussed.

Adult

The consistency of pulse frequencies and pulse patterns of transcutaneous electrical nerve stimulation (TENS) used by chronic pain patients.

This study records the consistency of transcutaneous electrical nerve stimulation (TENS) pulse frequency and pulse pattern used by 13 chronic patients over a 1 year period. The results show that patients prefer specific pulse frequencies and pulse patterns unique to the individual and that they turn to such frequencies and patterns on subsequent treatment sessions. Pulse frequencies and pulse patterns were not related to the cause and site of pain, a finding consistent with previous study in this laboratory. This observation, coupled with the large variability in pulse frequencies and pulse patterns used between individuals, implies that patients prefer such frequencies and patterns for reasons of comfort which may not be related to mechanisms specific to the pain system.

Adult

The effects of auricular transcutaneous electrical nerve stimulation (TENS) on experimental pain threshold and autonomic function in healthy subjects.

The present study examines the effects of auricular transcutaneous electrical nerve stimulation (TENS) on electrical pain threshold measured at the ipsilateral wrist and autonomic functions including skin temperature, blood pressure and pulse rate in 24 healthy subjects. TENS was administered as low frequency trains of pulses delivered at a 'strong but comfortable' intensity to 1 of 3 auricular points to be examined: (i) autonomic effects (autonomic point), (ii) pain threshold effects (wrist point), and (iii) placebo effects at an unrelated point (face point). A fourth untreated group was designated as a situation control. The main finding of the study was that auricular TENS produced no significant overall effects on experimental pain threshold or autonomic functions recorded under the present conditions. However, pain threshold was found to increase by over 50% of its pretreatment baseline in 4 subjects and by 30% in 6 subjects. This rise was not dependent upon the site of auricular TENS. The possible mechanisms of such changes are discussed.

Adolescent

Hospital prescribing and usage of hypnotics and anxiolytics.

In-patient prescribing and usage of hypnotic and anxiolytic drugs were surveyed in a teaching hospital for 4 to 6 weeks. Twenty-one percent of admissions were prescribed these drugs which were predominantly benzodiazepines. Few patients (1.6%) were discharged with such prescriptions and subsequent usage in the community was similar to that before admission to hospital (6.1% and 6.4% respectively). In-patient consumption increased with patient age and both prescriptions and consumption were greater in women than men.

Anti-Anxiety Agents

Solvent abuse.

Explore the source record for details and available documents.

Adolescent

Estimation of human blood plasma 5-hydroxyindoleacetic acid and homovanillic acid.

A method for simultaneous quantification of plasma homovanillic acid and 5-hydroxyindoleacetic acid has been developed, permitting more efficient neurochemical examinations of these often interrelated biogenic amine systems. Zinc sulphate and sodium hydroxide solutions were used for precipitating the protein in plasma prior to injection on the column. This technique allows for cleaner chromatography, greater sensitivity and high precision. The method uses high performance liquid chromatographic separations of these compounds on C18 reversed phase columns with electrochemical detection. The detailed results from controls and untreated parasuicide patients are given.

Chromatography, High Pressure Liquid

A double-blind placebo-controlled study of buspirone in diazepam withdrawal in chronic benzodiazepine users.

A double-blind placebo-controlled trial of 23 chronic benzodiazepine users showed that overall, buspirone did not appear to be helpful in alleviating benzodiazepine withdrawal symptoms. Buspirone (5 mg t.d.s.) or placebo was administered for four weeks before, during and after diazepam withdrawal. Patients taking buspirone had a markedly higher dropout rate (seven out of 11) than those taking placebo (one out of 12). Mean daily diazepam dosage at entry was significantly higher in the buspirone group, but overall initial diazepam dosage was not related to outcome. Higher subjectively rated anxiety at the start of withdrawal was significantly related to higher dropout rate, irrespective of treatment, and was greater (although not significantly so) in the buspirone group.

Adult

Analgesic effects of different frequencies of transcutaneous electrical nerve stimulation on cold-induced pain in normal subjects.

The efficacy of transcutaneous electrical nerve stimulation (TENS) in producing analgesia in cold-induced pain was assessed using a range of 5 stimulating frequencies (10 Hz, 20 Hz, 40 Hz, 80 Hz and 160 Hz) in 83 normal healthy subjects. TENS significantly elevated ice pain threshold when compared with sham and control groups. TENS frequencies between 20 and 80 Hz produced greatest analgesia, while frequencies below and above this level (10 Hz and 160 Hz), although significantly elevating ice pain threshold, produced effects of a lesser magnitude. The frequency of pulse delivery was the governing factor as no significant differences in stimulus intensity were observed across the treatment groups. Measurement of ice pain tolerance was found to be unreliable under the present conditions. No significant relationships were observed between personality variables as measured by Eysenck Personality Questionnaires and the degree of TENS response.

Adolescent

Comprehensive clinical drug information service: first year's experience.

A comprehensive clinical drug information service, established in the Northern Region in May 1975, is manned by eight doctors--all clinical pharmacologists--and is available 24 hours a day. In the first year of operation 451 inquiries were received, 354 (78-5%) of which were "consultative." Though junior hospital doctors used the service most, almost half of the inquiries about adverse reactions to drugs came from consultants.

Drug Information Services