PubMed Health⌕ Search

Biomedical subjects

H Ashton

Publications and source records attributed to H Ashton.

17 recordsLinked to original sources
PubMed1991

Protracted withdrawal syndromes from benzodiazepines.

The benzodiazepine withdrawal syndrome is a complex phenomenon which presents serious difficulties in definition and measurement. It is particularly difficult to set out precise limits on its duration. Many withdrawal symptoms are a result of pharmacodynamic tolerance to benzodiazepines, some mechanisms for which are discussed. Such tolerance develops unevenly in different brain systems and may be slow to reverse. Withdrawal symptoms occurring in the first week after cessation of drug use tend to merge with more persistent symptoms that may last for many months. These prolonged symptoms do not necessarily constitute "true" pharmacological withdrawal symptoms, but are nevertheless related to long-term benzodiazepine use. Such symptoms can include anxiety, which may partly result from a learning deficit imposed by the drugs, and a variety of sensory and motor neurological symptoms. The protracted nature of some of these symptoms raises the possibility that benzodiazepines can give rise not only to slowly reversible functional changes in the central nervous system, but may also occasionally cause structural neuronal damage.

Aged↗
PubMed1991

Psychotropic-drug prescribing for women.

The reasons for women in Europe and North America being prescribed over twice as many psychotropic drugs as men are complex. Psychiatric disorders such as depression and anxiety appear to be more common in women than in men, and women more commonly complain of psychological symptoms. There may be a gender bias in medical diagnosis and choice of medication. Sociological factors may also be involved, including the likelihood that women have fewer outlets than men for symptom control by activities outside the home (e.g. the social use of alcohol). Women also have special problems including pregnancy, lactation, child rearing and pre-menstrual tension. Probably, much use of psychotropic-drug use for women (and men) is inappropriate and not closely related to the symptoms or conditions for which they are prescribed. Furthermore, the chronic use of some psychotropic drugs, especially benzodiazepines, may compound the problem by inducing dependence and withdrawal symptoms.

Drug Prescriptions↗
PubMed1989

Tranquillisers: prevalence, predictors and possible consequences. Data from a large United Kingdom survey.

Data related to tranquilliser/hypnotic use is presented from a large (n = 9,003) random representative United Kingdom sample of adults (18+ years). On the day of interview 4.2% of females and 2.1% of males reported current use of tranquillisers. Increased probability of current use was significantly related to female sex, older age, increased symptoms of psychological malaise and physical ill-health, elevated neuroticism scores on the Eysenck Personality Inventory, lower socioeconomic status, unemployment, current smoking in some groups, and less participation in active leisure pursuits. There was no convincing trend with standard geographical region.

Adult↗
PubMed1988

Cortical evoked potentials and clinical rating scales as measures of depressive illness.

Relationships between clinical ratings and cortical evoked potentials were examined before and during antidepressant drug treatment in 32 patients with major depressive disorder (DSM-III). Clinical rating scales included Hamilton Rating Scale for Depression, Beck Depression Inventory, Present State Examination (PSE) and Newcastle Scale. Evoked potentials included contingent negative variation (CNV), post-imperative negative variation (PINV) and auditory evoked potential (AEP) There were close correlations between all rating scales, and factor analysis produced only one component, suggesting that the common variance between them related to severity of depression. CNV magnitude before treatment correlated negatively with severity of depression regardless of diagnostic category. Depressed patients had a prominent PINV which persisted during antidepressant treatment. The amplitude of late components (N1P2) of the AEP was reduced strikingly in patients with a history of suicide attempts.

Adult↗
PubMed1979

Self-titration by cigarette smokers.

An 11-week crossover study was carried out in which 12 subjects smoked high-nicotine (1.84 mg standard yield) and low-nicotine (0.6 mg) cigarettes after an initial period of smoking their usual brands with a medium-nicotine yield (mean 1.4 mg). Plasma and urine nicotine concentrations, carboxyhaemoglobin (COHb) concentration, puffing behaviour, 24-hour cigarette consumption, and butt nicotine content were measured. The changes in plasma nicotine and blood COHb concentrations showed that the smokers compensated for about two-thirds of the difference in standard yields when switched to either high- or low-nicotine cigarettes. Thus, compared with the medium-nicotine brand, the intake of nicotine and carbon monoxide was only about 10% higher when subjects smoked the high-nicotine cigarettes, which had a standard yield 30-40% higher than the medium brands; and only about 15% lower when they smoked the low-nicotine cigarettes, which had a standard yield about 50% lower than the medium brands. But nicotine content and urine nicotine concentrations followed a similar pattern. Changes in puffing behaviour and in 24-hour cigarette consumption were only slight.The results show clear evidence of both upward and downward self-titration of nicotine and carbon monoxide (and tar) intakes when smokers change to cigarettes with standard yields that differ over the range studied.

Adult↗
PubMed1978

A comparison of some physiological and psychological effects of Motival (fluphenazine and nortriptyline) and diazepam in normal subjects.

1 The effects in normal subjects of a single oral dose of Motival (one tablet, containing fluphenazine 0.5 mg and nortriptyline 10 mg) on the contingent negative variation (CNV), reaction time, heart rate, blood pressure and self-rating scales for alertness, anxiety, tension, detachment and depression were compared with those of diazepam (5 mg and 7.5 mg) and placebo or propranolol (60 mg). 2 After diazepam (5 mg: twelve subjects and 7.5 mg: seven subjects) there was a significant decrease in CNV magnitude while after Motival (twelve subjects) there was no significant alteration in CNV magnitude compared to placebo. 3 After diazepam (7.5 mg: seven subjects) there was also a fall in subjective ratings for alertness and tension; this fall was significantly greater than the changes after Motival which did not reduce subjective ratings for alterness or tension below "average" levels. Anxiety ratings did not differ significantly between the two drugs. Changes after propranolol were intermediate in all scales. 4 It is concluded that under these conditions diazepam caused central nervous system depression while Motival did not.

Blood Pressure↗
PubMed1975

Cigarette smoking in pregnancy: differences in peripheral circulation between smokers and non-smokers.

Ten smokers and ten non-smokers were followed serially from 12 to 16 weeks of pregnancy to six weeks postnatally. Measurements of calf and foot blood flow and toe and finger skin temperature were made at 4 to 6 week intervals in both groups, and the acute effects on the peripheral circulation of smoking one standard cigarette were also measured in the smokers at each stage of pregnancy. Comparison between the smokers and non-smokers showed that in the last trimester of pregnancy smokers had significantly higher foot blood flow and toe and finger temperature than non-smokers. These circulatory variables rose during the period of pregnancy studied in smokers but altered little in non-smokers. There was no significant difference in calf blood flow between the groups. Smoking a cigarette during pregnancy caused a fall in foot blood flow and in finger and toe skin temperature. Smoking increased calf blood flow between 12 and 25 weeks of pregnancy but decreased it in late pregnancy. Previous investigations of blood flow in pregnancy have not differentiated between smokers and non-smokers. It is suggested that the rise in foot blood flow and skin temperature believed to occur generally during pregnancy applies mainly to smokers. Some possible reason for differences in skin blood flow between smokers and non-smokers in pregnancy are discussed.

Adult↗
PubMedDate not supplied

The effect of increased tissue pressure on blood flow.

Theoretical consideration of the factors involved in maintaining vascular equilibrium and experimental evidence in animals and man indicate that at high tissue pressures there may be a sharp decline in blood flow and, in certain situations, complete cessation of blood flow even at tissue pressures below mean arterial pressure. At least two mechanisms appear to be involved: active closure of small arterioles under vasomotor tone when transmural pressure is lowered, either by falls in intravascular pressure or rises in tissue pressure, and passive collapse of soft-walled capillaries when tissue pressure rises above intracapillary pressure. These mechanisms are likely to assume particular importance when tissues are surrounded by non-compliant fascia and may thus be involved in compartmental syndromes.

Anterior Compartment Syndrome↗