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Biomedical subjects

H U Fisch

Publications and source records attributed to H U Fisch.

At least 55 records · Page 3Linked to original sources
PubMed1984

[Saccadic eye movements as a measure of the pharmacodynamics of benzodiazepines. Evaluation of various occulographic parameters].

Effects of a single dose of 0.25 mg triazolam p.o. on saccadic eye movements were studied in 6 healthy volunteers. Triazolam was chosen because of its short half-life of 2.5 hours. Peak velocity, duration, acceleration/deceleration index, ratio of hypometric saccades and number of corrective saccades were measured before and at repeated intervals after triazolam administration over a period of 9 hours. Maximal change compared with baseline was observed 90 min. after drug administration. After 9 hours baseline values were reached. As with other benzodiazepines, peak velocity and duration of saccades were the most reliable parameters. Additionally, the number of corrective saccades was found to be a sensitive indicator of drug-induced impairment of oculomotor performance. The present study again emphasises the importance of saccadic eye movements for assessing effects of sedative drugs.

Adult↗
PubMed1983

Influence of diazepam and methylphenidate on identification of rapidly presented letter strings: diazepam enhances visual masking.

The effect of diazepam (0, 5, 10 mg) and methylphenidate (0, 5, 10 mg) on the identification of briefly displayed letter strings composing words was investigated. Each letter was presented for 70 ms. The interstimulus interval (ISI) between two successive letters was 10, 100 or 200 ms. The length of the words (WL) was three, five, seven or nine letters. The dependent variable was the number of correctly identified words. As predicted, strong visual masking effects, the strength of which was dependent on ISI and WL, appeared. In the 10 ms condition, diazepam at both doses, but not methylphenidate, further enhanced masking. It is suggested that the results reflect the effect of GABA on masking, and support certain psychological theories about the inhibitory neuronal pathways that are involved in masking. The human peripheral visual system is a promising model for the experimental assessment and integration of pharmacodynamic, neurophysiological and psychological observations.

Adult↗
PubMed1983

Triazolam concentration-effect relationships in healthy subjects.

Triazolam was used to study the plasma concentration-effect relationship of a benzodiazepine because it has a very short plasma t1/2. A standard hypnotic dose of 0.25 mg was given by mouth to six healthy subjects, and blood samples were drawn when the subjects had to perform a battery of psychologic tests. Only the digit-symbol substitution test, the card-sorting test according to numbers, and the visual analog scale (energetic-lethargic) gave significant results. Analysis of the concentration-effect relationship in individuals indicated a wide scatter of the data. Mean values revealed a trend for a learning effect in the card-sorting test. The results are consistent with the hypothesis that triazolam is well suited for a study of concentration-effect relationships, but better psychologic tests would be desirable.

Adult↗
PubMed1982

A cross-national study of drug treatment decisions in psychiatry.

It is generally believed that American psychiatrists prescribe higher doses of psychoactive drugs than do European psychiatrists. This belief is based on cross-national studies that compared different groups of psychiatrists treating different patients, thus confounding patient and physician variables. An experimental approach derived from cognitive psychology was used to present identical patient material to a group of American psychiatrists and to two groups of Swiss psychiatrists. Cross-national differences were confirmed--the Americans prescribed much higher doses than the Swiss. Considerable differences in doses prescribed were also found between the two Swiss groups. Neither group was very consistent in prescribing. Agreement about choice of drug among psychiatrists in all three groups was low; agreement among the Americans was not above chance.

Cross-Cultural Comparison↗
PubMed1982

On evaluating the severity of depression: an experimental study of psychiatrists.

This study extends earlier work on the evaluation of depression by general physicians, and compares the results obtained with that group with those from a group of experienced psychiatrists. Differences within each group were larger than those between them. In neither group were individuals able to describe their own diagnostic processes with great accuracy, but psychiatrists were, as expected, somewhat more consistent than general physicians. They became even more so when allowed to select their own cues; of which, however, they made use of a smaller number. These tended to be of a specific rather than (as with the physicians) of a general nature.

Adult↗
PubMed1981

An experimental study of the clinical judgment of general physicians in evaluating and prescribing for depression.

Fifteen general physicians were given profiles of symptom combinations representing 80 depressed patients. They were asked to judge the severity of the disorder and to prescribe. There were two phases to the experiment, the formal structure of both being the same. In the first phase, all physicians based their judgments only on the cues of the Hamilton Depression scale; in the second, each physician defined his own cues. Multivariate regression analysis was applied to the observations. Agreement between the judges was low. Most had a more complex policy, in regard to both judgment of the severity of the depression and prescribing, when selecting their own cues than when restricted to textbook variables, but used it more consistently. The observations have important implications for training and research in psychiatry and in psychopharmacology.

Adult↗
PubMed1979

[Sociopharmacology--psychoactive drugs as an example].

Psychoactive drugs influence the social behavior of men and primates deeply. Many neuroleptics block the activity of social learning and therefore have an antitherapeutic effect. Sociopharmacology deals with drug effects which have no pharmacological basis: placebo effects, and physician and patient expectations from the drug which may lead to self-fulfillling prophecies. When the physician is prescribing psychoactive drugs he is under numerous influences: the expectations of the patient; the pressure of his therapeutic helplessness in view of many odd illnesses which cannot be explained somatically; his professional obligation to treat the patient; and marketing. The importance of a trusting doctor-patient relationship as a pre-requisite for successful treatment with psychoactive drugs is discussed.

Animals↗