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Biomedical subjects

R B Lydiard

Publications and source records attributed to R B Lydiard.

At least 163 records · Page 9Linked to original sources

Can panic disorder present as irritable bowel syndrome?

Five patients who had been diagnosed with panic disorder and irritable bowel syndrome are described. Both panic and gastrointestinal symptoms responded dramatically and rapidly to pharmacologic treatment of panic symptoms in all five patients. The frequent overlap of gastrointestinal symptoms and psychiatric (particularly anxiety) disorders suggests that some patients with functional gastrointestinal complaints may have a primary anxiety disorder.

Adult↗

The dexamethasone suppression test in agoraphobia.

Patients diagnosed as having agoraphobia with panic attacks by DSM-III criteria were evaluated with the dexamethasone suppression test (DST). Depressive symptoms were assessed using the Beck Depression Inventory, the Depression Scale of the Minnesota Multiphasic Personality Inventory, and the Hamilton Rating Scale for Depression. Of 97 patients tested, 12.4% had a positive DST. These findings are consistent with earlier reports that found an incidence of abnormal DSTs between 11% and 15% in agoraphobic patients. Abnormal DSTs did not correlate with levels of depression on any of the depression measures.

Adult↗

Tricyclic-resistant depression: treatment resistance or inadequate treatment?

The apparent resistance to tricyclic antidepressant treatment of many depressed patients often may be a result of an inadequate therapeutic trial. Several potentially important variables which may contribute to apparent treatment resistance are discussed, including interpatient pharmacokinetic variability, noncompliance, and inadequate duration of treatment. The current status of the relationship of clinical response and plasma levels of tricyclics and the use of therapeutic blood monitoring to reduce the failure rate in tricyclic antidepressant treatment are also discussed.

Amitriptyline↗

Rate-sensitive inhibition of ACTH release in depression.

Rate-sensitive inhibition of ACTH release is abnormal in Cushing's disease but uncharacterized in depression. The authors found that two of 10 depressed patients had paradoxical responses, suggesting the existence of a hypothalamic-pituitary-adrenal axis abnormality in depression that is independent of dexamethasone suppression test results.

Adrenocorticotropic Hormone↗

Double-blind comparison of amoxapine and imipramine in the treatment of depressed patients.

A 5-week double-blind study compared amoxapine to imipramine (2:1 dosage ratio) in the treatment of depressed outpatients. The two agents were similar in anti-depressant efficacy and rapidity of action. The most common adverse reactions to both drugs were anticholinergic effects and sedation; cardiovascular effects were minimal. A few amoxapine-treated patients developed adverse effects typical of neuroleptic drugs: some experienced extrapyramidal signs, one developed galactorrhea, and most showed elevated plasma prolactin concentrations. Amoxapine was associated with significant neuroleptic activity in plasma. No correlation was found between blood levels of either drug and therapeutic response.

Adolescent↗

Desipramine-associated SIADH in an elderly woman: case report.

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) has numerous etiologies, including medical illness, stress, and various pharmacologic agents. While a number of psychotropic agents may induce SIADH, only a few reports of tricyclic-antidepressant-induced SIADH exist. A case of SIADH associated with desipramine treatment in an elderly depressed woman is described.

Aged↗

Postnatal behavioral alterations resulting from prenatal administration of dl-alphamethylparatyrosine.

We have previously reported that injection of dl-alphamethylparatyrosine methylester (AMPT) into the yolk sac of fertilized chicken eggs prior to incubation results in dose-related increases in the specific activity of tyrosine hydroxylase (TH) at 29 days postnatally. We now report that injection of 10.0 and 33.3 mg/kg of AMPT prior to incubation results in dose-related increases in acquisition rates of 2 operant responses. Between 1 and 3 weeks of postnatal age, we observed a dose-related decrease in latency to perform a detour response and, at 55-60 days of postnatal age, an increased rate of acquisition of a key peck response in an autoshaping paradigm. We could not discern any significant alteration in several measures of unconditioned behaviors in an open field situation at 3 weeks of postnatal age. Our data support the contention that early catecholamine (CA) depletion can produce long-term alterations in postnatal behavior.

Age Factors↗

Postnatal elevation of brain tyrosine hydroxylase activity, without concurrent increases in steady-state catecholamine levels, resulting from dl-alpha-methylparatyrosine administration during embryonic development.

Increased specific activity of tyrosine hydroxylase (TH) in the brains of embryonic and 29-day-old chickens results from exposure to reserpine during the early stages of embryogenesis. We have also reported significant increases in the steady-state concentrations of catecholamines (CAs) in the brains of these 29-day-old chickens, suggesting permanent alterations in the control mechanisms during a critical period of development. The specificity of embryonic CA depletion in the above findings was examined usind dl-alpha-methyl-para-tyrosine (AMPT) as a depleting agent. AMPT, injected in varying doses into the yolk sac of fertilized chicken eggs prior to incubation, caused embryonic CA depletion by day 10 of embryogenesis but repletion had occurred by 20 days of embryogenesis. TH activity in whole brain and brain parts was elevated in a dose-related fashion at 29 days postnatally by AMPT. However, no changes in steady-state CA levels in whole brain were observed at this time after AMPT. Differences in the responses to reserpine and AMPT are discussed with respect to their pharmacological actions. The data support the contention that early embryonic CA depletion can result in long-term increases in TH activity postnatally, but steady-state levels of product need not necessarily be altered.

Age Factors↗

Amoxapine--an antidepressant with some neuroleptic properties? A review of its chemistry, animal pharmacology and toxicology, human pharmacology, and clinical efficacy.

Amoxapine, a new antidepressant, exhibits both antidepressant and neuroleptic effects in laboratory animals and in humans. Evidence from human studies (extrapyramidal reactions, hyperprolactinemia, and galactorrhea), animal screening tests, and neurochemical experiments support the contention that amoxapine or a metabolite occasionally produces neuroleptic-like effects. Amoxapine's neuroleptic activity may derive from 7-hydroxy-amoxapine, a minor metabolite in humans, which exhibits significant dopamine receptor-blocking activity. Evidence for an early antidepressant effect of amoxapine in the treatment of depressive illness has not been consistently demonstrated. In comparable doses (roughly twice the dose of imipramine or amitriptyline), amoxapine appears to be similar to reference antidepressants in efficacy, unwanted effects, and acute toxicity.

Amitriptyline↗

Effect of fluvoxamine, imipramine and placebo on catecholamine function in depressed outpatients.

Many of the specific serotonin reuptake inhibitors appear to have some effect on noradrenergic function. Fluvoxamine is one of the newer agents and its specificity has not been fully assessed. Depressed patients participating in a study comparing the efficacy of fluvoxamine with imipramine and placebo collected 24 hour urine samples (N = 38) and had plasma samples drawn (N = 38) prior to and after 6 weeks of double blind treatment. Urine samples were analyzed for 24 hour output of MHPG, VMA, NMN, MN and HVA. Plasma samples were analyzed for NE levels. Imipramine treatment produced a reduction in urinary MHPG, an increase in the ratio of NMN to MHPG plus VMA, and a trend towards an increase in plasma NE which was significantly different than the effects seen in the fluvoxamine and placebo groups. There was an additional finding in the imipramine group of a significant correlation between percentage change in plasma NE and clinical improvement. Fluvoxamine treatment, on the other hand, produced no clear effect on any measure of noradrenergic function and the antidepressant efficacy of fluvoxamine was unrelated to any noradrenergic variable. These findings lend support to the hypothesis that fluvoxamine does not have significant effects on noradrenergic function.

Adolescent↗

Antidepressants in panic disorder and agoraphobia.

A survey of the literature on the use of antidepressants for treating patients with panic disorder and agoraphobia with panic attacks suggests that both tricyclic antidepressants and monoamine oxidase inhibitors have efficacy in blocking panic attacks. While we have witnessed dramatic progress in the pharmacological treatment of panic-related disorders over the past 20 years, many unresolved questions remain. Further understanding of dose-response relationships, optimal duration of treatment and predictors of relapse are needed to optimize pharmacological treatment of panic-related disorders. Studies comparing the relative efficacy and side effects spectrum of various effective medications are needed. It is not presently possible to specify which patients will require medication or behavioral treatment alone, and studies to date have incompletely examined this murky issue. Further prospective studies directly comparing the pharmacological and behavioral treatments will help further elucidate the relative contribution of each treatment and possibly clarify which patients require both treatments. Controlled studies in the future which standardize dosage and duration of treatment and use comparable, objective outcome variables promise to provide important theoretical and clinical information regarding the pharmacological treatment of panic-related disorders.

Agoraphobia↗

Prevalence of psychiatric disorders in patients with irritable bowel syndrome.

Thirty-five patients with irritable bowel syndrome were referred from the gastroenterology service and underwent structured psychiatric interviews to assess the prevalence of psychiatric illness. Thirty-three (94%) of 35 patients were found to have a lifetime prevalence of any Axis I disorder; the predominant diagnoses were mood and anxiety disorders. Theoretical and practical implications of these findings are discussed.

Adult↗