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Biomedical subjects

T Silverstone

Publications and source records attributed to T Silverstone.

At least 73 records · Page 4Linked to original sources
PubMed1988

A clinical trial of the efficacy and acceptability of D-fenfluramine in the treatment of neuroleptic-induced obesity.

Twenty-nine overweight schizophrenic patients maintained on depot neuroleptic injections who wished to lose weight took part in a double-blind, placebo-controlled trial of 30 mg D-fenfluramine. All subjects received dietary advice. Sixteen patients completed the 12-week trial. Rate of weight loss was significantly greater in those taking D-fenfluramine. Side-effects were reported, but no deterioration in mental state was noted.

Adult↗
PubMed1988

Prevalence of obesity in patients receiving depot antipsychotics.

Antipsychotic drugs have long been noted to cause pronounced weight gain, and drug-induced obesity can assume major clinical importance in long-term medication in the management of chronic schizophrenia. Obesity is associated with increased morbidity and may reduce compliance, leading to a return of psychotic symptoms. In a survey of 226 patients attending depot neuroleptic clinics in one inner London borough, it was found that the prevalence of clinically relevant obesity was four times that in the general population.

Adult↗
PubMed1988

The interaction of metergoline, a 5-HT receptor blocker, and dexfenfluramine in human feeding.

Use of the 5-HT antagonist metergoline (MTG) has shown that dexfenfluramine (d-FF) influences food intake in animals via serotoninergic neurones. This study examined the interaction between d-FF and MTG in humans. Healthy male volunteers reported singly at 8:45 A.M. on four weekly occasions following an overnight fast. At 9:00 A.M. they received 30 mg d-FF or matching placebo and at 11:00 A.M. 4 mg MTG or placebo. Hunger and satiety were assessed hourly using visual analog scales (VAS). Subjects had access to a 4-channel automated food dispenser (AFD) from 1:15 to 3:15 P.M. Delivery and recording of each portion of known energy value was contingent on an appropriate button push. Subjects were offered two nonsweet snacks, plus fruit and a chocolate biscuit chosen to each subject's preference. Results for 13 subjects are reported. d-FF reduced hunger VAS, MTG had no effect on hunger and did not attenuate the effect of d-FF. d-FF reduced total food intake by 1306 kJ (312 kcal p less than 0.01) at 120 min. MTG increased food intake and attenuated the effect of d-FF on food intake but not significantly. d-FF markedly reduced the intake of nonsweet food; this was attenuated by MTG which alone had no effect on nonsweet food. d-FF had no effect on the intake of sweet tasting food during the first hour; by 120 min it had reduced energy intake by 342 kJ (82 kcal, t = 1.34, n.s.).(ABSTRACT TRUNCATED AT 250 WORDS)

Drug Interactions↗
PubMed1987

Receptor blocking drugs and amphetamine anorexia in human subjects.

The interaction between the receptor antagonist thymoxamine (THYM), propranolol (PPL) and metergoline (MTG) with dexamphetamine (d-Amp)-induced anorexia was examined in a series of studies in normal female volunteers. Visual analogue scale (VAS) ratings of hunger were made and food intake was measured using an automated solid food dispenser (AFD). d-Amp (10 mg) significantly depressed hunger ratings compared to placebo in two of the three studies and its effect was countered by the addition of MTG (4 mg). d-Amp significantly reduced food intake compared to placebo in two studies. In all trials the reduction in food intake following d-Amp was significantly greater than would have been predicted from its effect on hunger. THYM (160 mg) and PPL (40 mg) were associated with no changes in food intake when given alone or with d-Amp, MTG increased food intake (but not significantly) and the combined effects of MTG and d-Amp was the algebraic sum of the effect of each; but there appeared to be no true pharmacological interaction between blocker and anorectic. The results indicated that there may be some dissociation between the effect of d-Amp on hunger and food intake but have failed to produce evidence that noradrenergic pathways are involved. The results are consistent with the theories that d-Amp anorexia does not involve the release of 5-hydroxytryptamine (5-HT) but that 5-HT pathways are involved in the feeding process.

Adult↗
PubMed1987

The interrelationship of beta endorphin, ACTH and cortisol in depressive illness: a controlled study.

Plasma cortisol, ACTH and beta endorphin were measured before and after dexamethasone in 8 severely depressed patients and 8 age- and sex-matched controls to examine the relationship of ACTH and endogenous opioids to cortisol in depression. Despite having significantly higher plasma levels of cortisol than the controls, the depressed patients did not have correspondingly elevated plasma levels of ACTH. Beta-endorphin levels were also similar in the two groups. All three hormones suppressed to some degree after dexamethasone, but cortisol suppressed less in patients than controls. Our findings suggest that in severe depressive illness abnormalities exist in the hypothalamic-pituitary-adrenal axis peripherally as well as centrally.

Adrenocorticotropic Hormone↗
PubMed1987

A comparative hospital survey of psychotropic drug prescribing.

In a survey of psychotropic drug prescribing for in-patients in three different types of psychiatric hospitals, the prevalence of combinations of more than one psychotropic drug varied from 45% in one hospital to 94% in another, with significant consistent differences between the use of drug combinations in the various hospitals. Combinations of two antipsychotic drugs were particularly frequent; the hospital with the lowest prevalence of polypharmacy was the only one with an associated psychopharmacology unit. Access to clinical pharmacology teaching may be an important factor in determining appropriate drug-prescribing habits.

Adolescent↗
PubMed1986

Serotoninergic mechanisms in human feeding: the pharmacological evidence.

This paper reviews the evidence of serotoninergic mechanisms in human feeding by considering the effects of 5-HT agonists, precursors and receptor antagonists on hunger, food intake and weight change in normal volunteers, obese people and psychiatric patients. Although there is compelling evidence for a serotonin (5-HT) mechanism being involved, the paper highlights the considerable individual variation in response to pharmacological manipulation of 5-HT. Such variation may reflect differences in the bio-availability of the drugs used. Subtle psychological factors may also play a role in blurring the pharmacological evidence for 5-HT involvement in the highly complex activity of human feeding.

Amitriptyline↗
PubMed1986

Dextroamphetamine-induced arousal in human subjects as a model for mania.

Because of the practical difficulties which arise in studying manic patients, a reproducible model for mania using human subjects would be a valuable adjunct to research in this condition. Dextroamphetamine, given as a single oral 20 mg dose, fulfils the criteria for such a model in that there are very close similarities between the changes which occur after dextroamphetamine and those which have been observed in mania in terms of subjective experience, physiological and endocrine changes, and response to pharmacological agents.

Administration, Oral↗
PubMed1986

The effects of methylamphetamine on mood and appetite in depressed patients: a placebo-controlled study.

Methylamphetamine given intravenously as a single 15 mg dose led to a pronounced elevation of mood in 7 out of 21 depressed patients compared to a control injection of sterile water administered on another occasion in random order under double-blind conditions. All 7 responders experienced an increase of VAS self-ratings of hunger in contrast to what has been observed in normal subjects who show a decrease in hunger after amphetamine. The implications of these findings are discussed in the light of monoamine theories of depression and appetite control.

Adult↗
PubMed1986

Single dose pharmacokinetics of 5 formulations of lithium: a controlled comparison in healthy subjects.

The single dose pharmacokinetics of 4 lithium preparations (Camcolit-400, Priadel, Liskonum, Litarex) and a new micro-encapsulated formulation were compared in normal volunteers using a balanced cross-over design. The data show an inverse relationship between rate of release and bioavailability. The pharmacokinetic characteristics of Camcolit-400 and Priadel were similar; both showed earlier and greater peak serum concentrations than the other 3. The new formulation, which accounted for most of the significant variance, had the slowest rate of release and the lowest bioavailability. Statistical analysis showed significant differences between the 5 preparations for C-max, T-max, 12-h serum levels, AUC and urinary excretion, but not for the 24-h serum levels. No serious untoward side-effects were noted.

Adult↗
PubMed1985

Plasma cortisol levels in mania: associated clinical ratings and changes during treatment with haloperidol.

Plasma cortisol levels were elevated in a large proportion of samples from manic patients. Although a correlation was found between clinical ratings of the severity of mania and the degree of elevation of daytime cortisol levels, some patients with low clinical ratings had elevated cortisol levels. During treatment with haloperidol, cortisol levels returned to normal earlier that the clinical state. The underlying mechanisms are discussed.

Adolescent↗
PubMed1984

The relationship of dopamine receptor blockade to clinical response in schizophrenic patients treated with pimozide or haloperidol.

Pimozide and haloperidol were found to be equally effective in the treatment of acute schizophrenia in a double-blind clinical trial involving 22 patients. Drug plasma levels measured by radioimmunoassay (RIA) did not correlate with clinical response following either drug. Nor was there any correlation between clinical response and the dopamine receptor blocking activity of either drug as measured by radio receptor assay (RRA). Following pimozide plasma prolactin (PRL) levels correlated with clinical change, although the time courses of response of PRL and clinical response were dissimilar. There was no correlation between PRL and clinical response to haloperidol. RRA and RIA values correlated highly following pimozide but not haloperidol. Our findings lead us to conclude that the RRA technique reflects the plasma level of a drug rather than its central dopamine blocking activity. We also consider that the clinical response to antipsychotic drugs in schizophrenia may be less directly linked to dopamine receptor blockade than has previously been supposed.

Acute Disease↗
PubMed1984

A double-blind non-crossover placebo-controlled study between group comparison of trazodone and amitriptyline on cardiovascular function in major depressive disorder.

The cardiovascular effects of trazodone ( TZD ), amitriptyline (AMT) and placebo were studied in out-patients with major depression. AMT was shown to have the expected effects on the electrocardiograph and on systolic time intervals consistent with its proven anticholinergic and quinidine-like properties. TZD , in contrast, had no quinidine-like effects and minor effects on systolic time intervals. However, it was not without any cardiovascular effects. Although TZD was shown to be a safer preparation than the reference drug AMT, long-term monitoring is needed to explain the minor effect on heart rate and T wave changes.

Adult↗