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Biomedical subjects

H Dekirmenjian

Publications and source records attributed to H Dekirmenjian.

At least 19 recordsLinked to original sources
PubMed1983

Excretion of catecholamine metabolites during methadone maintenance and withdrawal.

Catecholamine metabolites excreted by long-term methadone hydrochloride-dependent subjects were studied in a protocol involving a two-study design. After a two-week methadone maintenance period, 15 subjects underwent abrupt methadone withdrawal and 12 subjects, gradual methadone withdrawal. The first study compared levels of catecholamine metabolites excreted during the stable methadone period with those excreted during the abrupt withdrawal period, as well as with those eliminated by healthy nonaddicted controls. No changes in the excretion of 3-methoxy-4-hydroxyphenylglycol and normetanephrine were noted between the methadone maintenance period and the time of abrupt methadone withdrawal. These values did not differ from those obtained for controls. However, higher levels of metanephreine were excreted during the stable methadone period than those in controls. During withdrawal, levels of metanephrine dropped a statistically significant amount in comparison with levels observed during the stable methadone period. The gradual withdrawal study confirmed these findings.

Adult↗
PubMed1983

Effects of diet on urinary excretion of MHPG in normal preadolescent boys.

The authors examined the effect of diets with low and high monoamine content on the 24-hour urinary excretion of 3-methoxy-4-hydroxyphenylglycol (MHPG) and creatinine in eight healthy preadolescent boys. The subjects were admitted to a clinical research center and were placed on a diet low in monoamines--the vanillylmandelic acid (VMA)-exclusion diet--for 5 consecutive days. They were switched on the 6th day to a diet rich in monoamines, and urine specimens were collected for 4 more consecutive days. There were no differences in MHPG or creatinine excretion between the urine taken on the low and high monoamine diet days.

Child↗
PubMed1983

Blood levels of haloperidol in schizophrenic patients.

Plasma and red blood cell levels of haloperidol were measured in psychotic patients after an acute dose of haloperidol and during treatment with fixed doses for several weeks. There was wide variability of haloperidol plasma and red blood cell levels at a given dose and a nonlinear relationship between haloperidol dose and blood levels. The red blood cell/plasma ratio (0.40) had a narrow range among different patients. Haloperidol blood levels were not correlated with the age of the patient. Concomitant administration of benztropine mesylate did not decrease plasma haloperidol levels. Steady state plasma or red cell haloperidol levels could not be predicted from levels 24 hours after the acute dose.

Adolescent↗
PubMed1982

GLC analysis of trifluoperazine in human plasma.

This report describes a sensitive gas chromatographic procedure for the measurement of trifluoperazine in human plasma. Trifluoperazine was extracted into heptane-2-propanol by a two-step procedure and analyzed directly without derivatization. Prochlorperazine was employed as an internal standard because its structural and extraction characteristics were similar to trifluoperazine. The use of a nitrogen detection system reduced the number of interfering peaks. The within-day coefficient of variation in the methods, over a 0.2-20-ng/ml concentration range was 9.4%.

Chromatography, Gas↗
PubMed1982

Dopamine-norepinephrine interaction in hyperactive boys treated with d-amphetamine.

We studied the relationship between the excretion of 3-methoxy-4-hydroxyphenylglycol, the main metabolite of central nervous system norepinephrine, and homovanillic acid, the main metabolite of dopamine, in 16 hyperactive boys and ten controls who were admitted to a clinical research center. We further examined the effect of d-amphetamine (0.5 mg/kg body weight daily for two weeks) on that relationship. The correlation coefficients r between MHPG and HVA excretion were significantly negative in hyperactive boys and significantly positive in controls when the relational effects of age, body surface, and 24-hour urinary creatinine with MHPG and HVA excretion were removed. Furthermore, the correlation coefficient r in hyperactive boys and in responders at baseline differed significantly from the correlation coefficients in post-treatment and in controls. The post-treatment correlation coefficient in hyperactive boys and responders did not differ from that in controls. We suggest an altered relationship between DA and NE activity in hyperactive children. Meaningful interpretation of the data should await the availability of more information on the amount of contribution of central NE and DA metabolism to urinary MHPG and HVA in both hyperactive and normal children.

Age Factors↗
PubMed1982

Effects of d-amphetamine on urinary metabolites of dopamine and norepinephrine in hyperactive boys.

The authors measured the urinary metabolites 3-methoxy-4-hydroxyphenylglycol (MHPG) and homovanillic acid (HVA) in 21 hyperactive boys and 12 matched healthy boys. The hyperactive boys excreted lower amounts of MHPG than control boys. Hyperactive drug responders excreted lower amounts of HVA than control boys and hyperactive nonresponders. Drug responders with normal MHPG excreted low amounts of HVA and those with normal HVA excreted low amounts of MHPG. d-Amphetamine decreased MHPG in all drug responders and HVA in drug responders with normal HVA levels, although it tended to increase HVA in those with low HVA levels. The authors discuss their data in terms of the possible involvement of norepinephrine and dopamine in the etiology of hyperactivity in children.

Attention Deficit Disorder with Hyperactivity↗
PubMed1981

Fluphenazine determination in human plasma by a sensitive gas chromatographic method using nitrogen detector.

This report describes a sensitive gas chromatographic method with the use of a nitrogen detector for the determination of fluphenazine at therapeutic concentrations in human plasma. Fluphenazine was measured as its acetyl derivative. Perphenazine, a structurally similar phenothiazine, was used as an internal standard. The acetylated derivatives were identified by GC/MS. Within-day coefficient of variation of the method over the concentration range 0.5 to 10 ng/ml fluphenazine was 6.7%. Fluphenazine concentrations in the plasma of patients receiving the drug orally (as dihydrochloride) or intramuscularly (as decanoate) were measured. There were large interindividual variations both in plasma levels and half-lives of fluphenazine in different patients treated with the same doses.

Fluphenazine↗
PubMed1980

Phenothiazine levels in plasma and red blood cells. Their relationship to clinical improvement in schizophrenia.

A controlled study investigated the relationship between steady-state plasma and RBC concentrations of the phenothiazine derivative butaperazine maleate and the therapeutic response in 24 hospitalized schizophrenic patients who received constant maintenance doses of butaperazine during the first two weeks of treatment. Butaperazine concentrations in RBCs correlated significantly with clinical improvement in an inverted U-shaped pattern, whereas plasma levels of butaperazine were not significantly related to clinical response. Both plasma and RBC levels of butaperazine showed large interpatient variations. The level of RBC-bound drug might be a better peripheral correlate of drug levels in the brain than are drug levels in plasma. Thus, monitoring drug levels in RBCs might have an advantage over measured drug levels in plasma. These findings might not allow generalization to other antipsychotic agents.

Adolescent↗
PubMed1980

Congenital sensory neuropathy with anhydrosis-a case report and investigation of autonomic nervous system abnormalities.

A review of the clinical profile of congenital sensory neuropathy with anhydrosis is presented. It is stressed that major diagnostic criteria of this recessively inherited condition should be limited to insensitivity to pain with normal tactile perception, anhydrosis, recurrent unexplained fever, self-mutilation, mental retardation, hypotonia, histologically normal sweat glands and variable autonomic abnormality. A case conforming to this description is reported and compared with 13 published cases. Special investigations of the autonomic nervous system through measurement of urinary catecholamine metabolites and psychophysiologic variables were conducted on this patient. Based on the analysis of 5 X 24-hour urine, values of metabolites of dopamine and epinephrine were normal. Metabolites of norepinephrine, such as 3-methoxy-4-hydroxy phenylglycol and normetanephrine, however, were significantly low when compared with those of four controls, suggesting decreased peripheral and central norepinephrine activity. Polygraph recording and evaluation of some orienting response components revealed no obvious signs of autonomic perturbation and, specifically, no phasic electrodermal activity. These two findings (biochemical and electrodermal) strongly suggest an autonomic imbalance, specifically component, both central and peripheral. It is suggested that autonomic disorder is an integral part of the syndrome and may be demonstrated by special investigations.

Autonomic Nervous System Diseases↗
PubMed1979

Blood levels of neuroleptic drugs in nonresponding chronic schizophrenic patients.

Blood levels of butaperazine were measured in schizophrenic patients who were chronic nonresponders to their psychotropic medication. The blood levels were compared with those in patients who had shown a better clinical response to this neuroleptic. Nonresponders had two to seven times lower levels of butaperazine in plasma and RBCs after a single dose or chronic dosing. Some of the patients later treated with thioridazine or haloperidol had lower plasma levels of these neuroleptics also. No significant differences were found between nonresponders and relative responders in either the alpha- or beta-phase half-life of butaperazine in plasma and RBCs after administration of a single dose of the drug. Butaperazine and thioridazine levels were not related to previously administered amounts of neuroleptic drugs. These findings do not support the hypothesis that low blood levels are the result of faster systemic metabolism of the drug after it reaches the central circulation. Our results suggest that low blood levels of neuroleptics may be one important factor in the poor clinical response of some chronic schizophrenic patients.

Adult↗
PubMed1979

Relationship of butaperazine blood levels to plasma prolactin in chronic schizophrenic patients.

The relationship of plasma prolactin to plasma or red blood cell butaperazine levels was investigated in chronic schizophrenic patients treated with clinical doses of butaperazine, both after a single acute dose of the drug and during regular, twice daily butaperazine administration. Although there was a significant curvilinear relationship between peak plasma butaperazine levels after an acute single oral dose of butaperazine and the maximum prolactin response that we measured, steady-state levels of plasma or red cell butaperazine and plasma prolactin were not related. We conclude that plasma prolactin cannot be used as a substitute for or even as a rough indicator of butaperazine blood levels in chronic schizophrenic patients being treated with clinical doses of butaperazine.

Adult↗
PubMed1979

Norepinephrine metabolism and clinical response to dextroamphetamine in hyperactive boys.

The 24-hour urinary catecholamine metabolites 3-methoxy-4-hydroxyphenylglycol, normetanephrine, and metanephrine were measured in 23 hyperactive boys and 13 matched healthy controls. The hyperactive children excreted lower MHPG and higher NM (low MHPG/NM ratio) amounts than in controls. The administration of d-amphetamine in the dose of 0.5 mg/kg body weight divided over two doses daily for two weeks decreased MHPG excretion in the hyperactive children. When the hyperactive children group was divided into drug responders and nonresponders according to their pre- and post-treatment scores on the Conners Teacher Questionnaire, d-amphetamine administration decreased MHPG excretion in the responders and did not change it in the nonresponders. Percent decrease in MHPG excretion correlated significantly with percent change in the hyperactivity factor of the questionnaire on the Spearman Rank Order Correlation Coefficient. Pretreatment urinary metabolites did not differentiate the responders from nonresponders. It is suggested that a relationship between CNS norepinephrine metabolism and hyperactivity exists and that d-amphetamine may achieve its therapeutic action in hyperactive children by altering CNS NE metabolism.

Central Nervous System↗
PubMed1979

Determination of butaperazine in biological fluids by gas chromatography using nitrogen specific detection system.

A simple and sensitive gas chromatographic method for the quantitative determination of butaperazine in biological fluids is described. The use of a nitrogen specific detector reduces the number of interfering peaks, thereby increasing the number of samples that can be analyzed. When butaperazine is extracted from 2 ml of plasma, the coefficient of variation is 7.4% over the concentration range of 5-180 ng/ml. The method was used to measure the levels in plasma and red blood cells in schizophrenic patients treated with butaperazine. It was also extended to measure butaperazine levels in rat red blood cells, plasma, liver, and brain after intraperitoneal injection (15 mg/kg).

Animals↗