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Biomedical subjects

T B Cooper

Publications and source records attributed to T B Cooper.

At least 127 records · Page 7Linked to original sources

Effect of extended depot fluphenazine treatment and withdrawal on social and other behaviors of Cebus apella monkeys.

To examine whether or not prolonged exposure to a depot neuroleptic has either residual or "tardive pathological" effects on normal behavior, 38 Cebus apella monkeys were observed daily for 108 weeks. The issue of stress influencing such effects was also addressed. During weeks 25-48 half of the monkeys received 0.22 mg/kg fluphenazine decanoate, IM, every 3 weeks, with the dose increased to 0.33 mg/kg during weeks 49-72. Behavioral measures were combined to form composite behavioral variables which quantify four major aspects of behavior: self- and environment-directed behavior, affiliation, aggression, and normal locomotor activity. Mean plasma fluphenazine levels at 48 h post-injection were 0.13 (+/- 0.03) ng/ml for injections 3-8 and 0.24 (+/- 0.07) ng/ml for injections 11-16. The pre-study null hypothesis that the four major aspects of behavior would not be adversely affected by this treatment during the drug-discontinuation phase of the study (weeks 73-108) was not statistically negated. There were highly significant decreases in self- and environment-directed behaviors and affiliation during the treatment periods, implying that treatment may contribute to the negative symptoms of treated schizophrenics. Stress reduced the above effects. Aggression showed some increase during early drug discontinuation, accentuated by stress. Recovery of normal (baseline) behavioral scores began by week 7 after the last treatment. Mild (bucco-lingual) tardive dyskinesias persisted in 30% of the animals for a prolonged time.

Animals↗

Disappearance of memory deficits in outpatient depressives responding to imipramine.

We evaluated learning and memory in 50 depressed patients prior to and following 4 week treatment with imipramine compared to 21 normal controls tested at corresponding times. At baseline, the depressives did worse than normals on most memory tasks with the difficult memory tasks, regardless of store, modality or type of task best distinguishing between depressive and normal memory. Following imipramine treatment, responders performed better than nonresponders on the difficult memory tasks, and not significantly differently from controls on most tasks. This, as well as the fact that the responders improved to a greater degree than controls on most measures (in a few cases the difference was statistically significant) and the fact that at 4 weeks complete responders to imipramine did significantly better than partial responders to imipramine, indicates that relief from depression is highly related to improved memory functioning. The finding that complete responders to imipramine were not significantly worse than normal controls suggests that imipramine did not have significant adverse effects on memory.

Adult↗

Saliva and plasma desipramine levels in Asian and Caucasian volunteers.

Thirty-seven healthy volunteers (18 Asian, 19 Caucasian) ingested a single desipramine (DMI) dose of 1.0 mg/kg of body weight. Saliva and plasma samples were obtained at 1, 3, 5, 7, 12, 24, 48, 72, and 96 hrs after dosing. A nested repeated-measures analysis of variance (ANOVA) design was used to determine if the plasma/saliva DMI ratio varied between Asians and Caucasians over time. Regression analysis was used to assess the ability of saliva DMI to predict plasma DMI at any time point. The ANOVA results indicated no significant differences in DMI plasma/saliva ratios between Asians and Caucasians. There was a major effect of sampling time on the DMI plasma/saliva ratio (p = 0.0001), with the ratio falling from 1.78 at 1 hr to 0.15 at 96 hrs. At any given time at least 24 hrs after the dose, there was a significant relationship between saliva and plasma levels across individuals. However, across subjects, the 95 percent confidence limits for predicting plasma DMI from saliva DMI levels were relatively large. The potential roles and limitations of saliva DMI in pharmacokinetic studies and clinical drug monitoring are discussed.

Adult↗

Acute cardiovascular effects of tranylcypromine: correlation with plasma drug, metabolite, norepinephrine, and MHPG levels.

BACKGROUND: Recent case reports, small series, and uncontrolled, unblinded studies have suggested that tranylcypromine may produce pressor reactions in some patients. However, the physiologic mechanism underlying this cardiovascular change is unknown. METHOD: The authors studied the acute cardiovascular effects of tranylcypromine in 13 patients and attempted to correlate these changes with plasma measures of parent drug, possible pressor metabolites, norepinephrine, and 3-methoxy-4-hydroxyphenylglycol. RESULTS: Significant elevations in supine blood pressure occurred after administration of tranylcypromine and correlated with tranylcypromine dose. Similar changes were not observed in standing blood pressure measurements. In fact, an orthostatic decrease in blood pressure and increase in heart rate were observed. Amphetamine-like metabolites were not found. CONCLUSIONS: The authors speculate on possible mechanisms underlying these opposite cardiovascular effects.

Adult↗

2-Hydroxydesipramine and desipramine plasma levels and electrocardiographic effects in depressed younger adults.

Desipramine was given to 34 outpatients aged 20 to 51 years who had primary major depressive disorder but who were otherwise in good health. Daily dosage at bedtime was constant for the final 3 weeks of the 5-week study (mean, [SD] 169.1 [46.1] mg). Electrocardiograms done predrug and after 5 weeks were read by a cardiologist blind to the order in which they were performed. Plasma samples drawn 14 hours after the final study dose were assayed by high performance liquid chromatography; mean (SD) levels were 140.2 (140.0) ng/ml for desipramine and 56.5 (29.4) ng/ml for 2-hydroxydesipramine (2-OH-DMI). Heart rate and PR, QRS and QTc intervals were significantly greater at the end of the study than at baseline, while QT intervals were significantly less. Changes in heart rate and PR, QT and QTc intervals were significantly negatively correlated with the value of the respective cardiac parameters at baseline. Changes in PR interval were significantly positively correlated with log desipramine, log 2-OH-DMI and log (desipramine + 2-OH-DMI). Stepwise multiple regression analyses showed that, for PR interval, each of the three plasma level variables showed a significant ability to improve R2 over that obtained from baseline PR alone. These findings suggest that both 2-OH-DMI and desipramine plasma levels predict a prolongation of intracardiac conduction in younger adults and that monitoring both levels may be useful in the clinical management of certain younger adult patients.

Adult↗

Single-dose pharmacokinetics of fluphenazine after fluphenazine decanoate administration.

Fluphenazine decanoate is commonly used as part of maintenance treatment of schizophrenia, but its pharmacokinetics are poorly understood. We administered a single intramuscular dose of fluphenazine decanoate to nine patients and found that plasma fluphenazine level did not decline to 50% of the peak level by day 26 in any of the patients. This means that it has a long half-life measurable in months rather than weeks.

Adult↗

Double-blind placebo-controlled study of nortriptyline in depressed adolescents using a "fixed plasma level" design.

We performed a random assignment, double-blind, placebo-controlled study of nortriptyline (NT) in postpubertal 12- to 17-year-olds with Research Diagnostic Criteria (RDC) and DSM-III major depressive disorder. The protocol included a 2-week placebo washout phase and an 8-week double-blind, placebo-controlled phase with weekly plasma level monitoring. Active subjects had their plasma level placed at 80 +/- 20 ng/ml by using previously developed tables to determine the starting dose from a plasma level drawn 24 hours after a single dose administered at baseline. The study population was severely depressed and had a chronic, unremitting course prior to study; a high percentage of family histories with affective disorder, alcoholism, and suicidality; and a high rate of comorbidity. Of the 52 subjects enrolled, there were 17 placebo washout responders, 4 dropouts, and 31 completers (12 active and 19 placebo). Only one active subject responded; therefore, the study was terminated early. The mean NT plasma level was 91.1 (18.3 SD) ng/ml. The two treatment groups had similar postprotocol severity ratings. Subjects on active drug did not evidence the anticholinergic side effects reported in adult samples. The negative outcome in this study is similar to the findings in our previously reported NT study in prepubertal 6- to 12-year-olds.

Adolescent↗

Relationship of hydroxynortriptyline to nortriptyline concentration and creatinine clearance in depressed elderly outpatients.

Plasma concentration of E-10-hydroxynortriptyline is increased in the elderly and may be related to both renal clearance of hydroxynortriptyline and rate of liver hydroxylation of nortriptyline. In 25 ambulatory, depressed elderly outpatients treated with therapeutic doses of nortriptyline, relationships among plasma levels of nortriptyline and E-10-hydroxynortriptyline, and an estimate of creatinine clearance were examined. Plasma levels of E-10-hydroxynortriptyline (corrected for varying dosage) were significantly correlated with age and inversely correlated (r = -0.50) with creatinine clearance but not with notriptyline or Z-10-hydroxynortriptyline concentration. E-10-hydroxynortriptyline concentration was about 5 1/2 times that of Z-10-hydroxynortriptyline. By best subsets multiple regression analyses, the ratio of E-10-hydroxynortriptyline to nortriptyline level was best predicted by plasma nortriptyline concentration, creatinine clearance, and age, all of which accounted for 63% of the variance. These results corroborate and extend previous findings in elderly inpatients in whom creatinine clearance was measured directly. In addition, age had an effect on E-10-hydroxynortriptyline independently of creatinine clearance. Since E-10-hydroxynortriptyline concentration has been related to both therapeutic efficacy and toxicity during nortriptyline treatment, it may be important to assess nortriptyline hydroxymetabolites in elderly patients and in those with renal insufficiency.

Aged↗

Acute congestive heart failure in a 55-year-old man. Rheumatic carditis diagnosed by endomyocardial biopsy.

We describe a 55-year-old man who presented with acute left ventricular dysfunction and congestive heart failure caused by rheumatic carditis. The diagnosis of rheumatic carditis was established by percutaneous endomyocardial biopsy. Since many physicians may not be familiar with some of the clinical and histopathologic features of rheumatic carditis, we submit this report as a reminder that the disease has not disappeared, should be considered in the differential diagnosis of acute heart failure, and can be diagnosed by endomyocardial biopsy.

Acute Disease↗

Haloperidol blood levels and effects in schizophrenia and schizoaffective disorder: a progress report.

To test the hypothesis of a "therapeutic window," we have randomly assigned acutely exacerbating schizophrenic or schizoaffective patients to one of three plasma levels of haloperidol (HAL): 2-13, 13.1-24, or 24.1-35 ng/ml. Patients who did not improve after 6 weeks of this treatment were randomly assigned to one of the three haloperidol levels for another 6 weeks. The improvement was defined as at least 50 percent reduction of the Brief Psychiatric Rating Scale (BPRS) total score. The results obtained in 111 patients do not support any consistent relationship between plasma level of haloperidol and clinical improvement. Patients in the high haloperidol plasma range tended to have more side effects. These results suggest that the haloperidol doses used in clinical practice may be higher than necessary.

Adult↗

Regional effects of 6-hydroxydopamine (6-OHDA) on free radical scavengers in rat brain.

Superoxide dismutase (SOD), catalase, glutathione (GSH), and glutathione peroxidase (GSH-Px) were measured in the caudate-putamen (CPu), the hippocampus (HIP), and the brainstem (BS) of the brains of control animals and of rats treated with one intracerebroventricular infusion of 6-hydroxydopamine (6-OHDA). Injection of 6-OHDA resulted in significant decreases in the activity of SOD in the CPu, the BS, and in the HIP. There were decreases in catalase in the CPu and in the BS, but not in the HIP. GSH was reduced in the CPu and the BS but not changed in the HIP. There were small decreases in the activity of GSH-Px only in the BS. These changes may be secondary to the production of free radicals after the infusion of 6-OHDA in rat brain.

Animals↗