Search PubMed⌕ Search

Biomedical subjects

T B Cooper

Publications and source records attributed to T B Cooper.

At least 271 records · Page 15Linked to original sources
PubMed1973

Lithium kinetics in man: effect of variation in dosage pattern.

1. Utilizing a general stochastic theory of drug kinetics we have demonstrated that from the serum concentration curve derived from a single dose of lithium, it is possible to predict the steady state concentration, the time required to reach steady state, the dependency of these quantities on the time interval between drug administrations and the fluctuations in plasma level under steady state conditions.2. It has been shown in general that the more frequently the drug is administered the higher is the steady state level, the shorter is the time required to reach steady state, and the smaller are the fluctuations.

Biopharmaceutics↗
PubMedDate not supplied

Enantiomeric determination of the phenylmorpholinol metabolite of bupropion in human plasma using coupled achiral-chiral liquid chromatography.

A coupled achiral-chiral stationary phase liquid chromatographic technique was developed to separate and quantitate the enantiomers of the phenylmorpholinol metabolite (2) of the antidepressant bupropion (1) in human plasma. At the retention time of 2, a switching valve loaded a portion of the eluting compound onto a protein-bonded chiral stationary phase which resolved 2 into the (+) and (-) stereoisomers using an aqueous mobile phase of potassium phosphate (pH = 6.25) and 5% 2-propanol. All eluting compounds were monitored using UV detection at 214 nm, and no plasma endogenous material or other commonly used psychotropic drugs were found to interfere. Within-day and between-day variation were less than 6% over the expected concentration range, and a limit of quantitation of about 125 ng/mL of 2 was observed. Steady-state plasma samples from 17 patients receiving 1 were found to contain the (-) enantiomer to the extent of about 96% of total 2. The potential clinical implications of these results are not known since all previous pharmacological studies were carried out with the racemic 2.

Antidepressive Agents, Second-Generation↗
PubMedDate not supplied

The usefulness of DST in predicting response to antidepressants: a placebo-controlled study.

Seventy-two out-patients, 55 years or older, suffering from major depression were treated with either nortriptyline or phenelzine for seven weeks under placebo-controlled double-blind conditions. The dexamethasone suppression test (DST) was administered at baseline and at weeks 3 and 7 of treatment, and its usefulness in predicting and/or paralleling clinical response was examined. No correlation was found between baseline DST results and treatment response with antidepressants. Of 13 patients whose abnormal baseline DSTs normalized during treatment, six were responders and seven were nonresponders (P = 0.24). However, all (seven) patients whose DSTs persisted to be abnormal throughout the seven weeks did not respond. The authors conclude that the DST has not been shown to have practical value as an indicator of impending recovery from major depression in the elderly, but its failure to normalize may have ominous prognostic significance.

Aged↗
PubMedDate not supplied

Plasma dexamethasone and cortisol levels in depressed outpatients.

We investigated the 1-mg dexamethasone suppression test (DST) in 41 outpatients with major depressive disorder assessing the role of dexamethasone blood level, age and basal cortisol on DST results. Non-suppressors (approximately 25% of patients) had lower dexamethasone levels, and post-dexamethasone cortisol was negatively correlated with plasma dexamethasone; these findings were more significant after covarying out age and basal cortisol, factors that were also significantly associated to non-suppressors. A subgroup of patients (n = 19) also had 0.75-mg and 2.0-mg DST to evaluate whether a threshold dexamethasone blood level existed; a dexamethasone blood level greater than 1.5 ng/ml converted all non-suppressors to suppressors. Implications of these findings are discussed.

Adult↗
PubMedDate not supplied

Fluphenazine decanoate dose and severity of depression in patients with post-psychotic depression.

The authors examined the fluphenazine decanoate dose and the fluphenazine plasma levels in comparison with measures of severity of depression in schizophrenic and schizoaffective patients. All patients were selected for study on the basis of having stable, syndromally defined, antiparkinsonian non-responsive syndromes of post-psychotic depression. No meaningful relationships were found. The implications of this observation with regard to the notion that depressive symptomatology in such patients is neuroleptic-induced is discussed.

Adult↗
PubMedDate not supplied

Dose-related differences in the distribution of cocaine in the maternal-fetoplacental compartments in rats.

Our goals were to examine whether a high dose of cocaine to causing CNS toxic manifestations in the pregnant rats influences the delivery of cocaine to the fetus, and whether the non-placental compartments have a significant role in the distribution of cocaine to the fetal tissues. Either a low or high dose of cocaine was infused intravenously to near-term pregnant rats. Arterial blood pressure and heart rate were monitored. Cardiac output and uterine and placental blood flows were measured by using radiolabeled microspheres. Plasma and tissue samples were obtained from the mother, placenta, and fetus and analyzed for cocaine and its metabolites via capillary gas chromatography/mass spectrometry. A high dose of cocaine induced convulsions that were accompanied by increased arterial blood pressure and decreased uteroplacental blood flow. However, the distribution pattern of cocaine and metabolites in the mother and fetus were similar between the high and low dose groups. Considerable amounts of cocaine and its metabolites were in the placenta. Previously ignored non-placental tissues, such as the amnion and myometrium appear to be a significant source for cocaine accumulation in the fetus.

Animals↗