An open study of tolerability and pharmacokinetics of raclopride extended release capsules in psychiatric patients: a Canadian study

The tolerability and pharmacokinetics of raclopride extended release (ER) capsules have been evaluated after a single oral dose and at steady state, with 3 different daily doses in 4 male patients requiring neuroleptic treatment. In this 3-week open study, the drug was administered to patients in increasing bid doses of 8 mg, 12 mg and 16 mg, respectively, for each 1-week treatment period, following a 1-week placebo washout. With this limited number of patients, assessments of clinical chemistry, hematology, cardiovascular variables and adverse symptoms suggest that raclopride is safe and well-tolerated in the group studied. The administration of repeated doses of raclopride showed linear pharmacokinetics based on parameter values which are either constant (effective elimination half-life, total plasma clearance, and dose-normalized area under the plasma concentration-time curve) or varying proportionally (trough plasma concentration, peak plasma concentration, average plasma concentration and the area under the plasma concentration-time curve for a dosage interval at steady state) with the doses. The linear 1-compartment open model with zero-order absorption was the most appropriate pharmacokinetic model describing the raclopride plasma concentration profile after a single 8 mg dose of raclopride ER capsules. The ER formulation reduced the fluctuation between peak and trough plasma drug concentrations which has been reported before with instant release dosage forms. In this study, the increase of plasma prolactin concentrations above the normal limit was transient and returned to normal levels. Although the plasma prolactin concentration tended to increase with the drug dose, no direct relationship between raclopride dose and prolactin plasma concentrations was found. The correlation of plasma prolactin response with the plasma raclopride concentration showed a low level of hysteresis.

Individual differences in hypothalamic-pituitary-adrenal activity in later life and hippocampal aging

Variation in magnitude of cognitive decline in later life is a central feature of human aging. The more severe forms of dementias, such as Alzheimer's disease, clearly define one end of the spectrum. However, among those showing no obvious signs of clinical dementia there are considerable individual differences. Thus, although evidence for learning, memory, and language loss appears in some individuals as early as 50-55 years of age, many people continue to function alertly well into their 90s. These individuals exemplify what Rowe and Kahn (1987) have termed "successful" aging. The wide variability in CNS aging, often a nuisance factor in studies, are becoming a major focus for brain aging research (e.g., Gage et al., 1984;Gallager and Pelleymounter, 1988; Aitken and Meaney, 1990; Issa et al., 1990). Our studies over the past few years have added support to the idea that individual differences in hypothalamic-pituitary-adrenal (HPA) activity can account for part of the variation seen in neurological function among the elderly. In this article we discuss the evidence for the idea that adrenal glucocorticoids can compromise hippocampal function and, thus, produce cognitive impairments, as well as the potential mechanisms for these effects.

Reversible and selective inhibitors of monoamine oxidase A in the treatment of depressed elderly patients

The treatment of depression in the elderly population needs a thorough and careful work-up and an aggressive therapeutic approach. Any treatment initiative in this population often becomes difficult because of accompanying physical illness, concomitant medication, possible degenerative changes in central nervous system and age-related altered metabolic status. Despite unevenness in research findings, pharmacological treatment remains the mainstay of management of depression among elderly people. Currently available antidepressants, although effective, are problematic because of the increased vulnerability of the elderly to side effects. Recent research efforts to improve the efficacy and safety of drug treatment of depression resulted in development of reversible and selective monoamine oxidase inhibitors of the isoenzyme A (RIMA), with antidepressant efficacy comparable to tricyclic antidepressants and newer generation antidepressants. RIMAs include moclobemide, brofaromine, toloxatone and cimoxatone. Moclobemide is the most investigated available RIMA for therapeutic use at present. Its absorption and disposition in elderly individuals do not differ significantly from those in young healthy volunteers and depressed patients. The results of present clinical studies show that, in elderly depressed patients, moclobemide is at least as effective as other antidepressants. Its particular advantage is, however, that it is as well tolerated in elderly people as in younger people. There are only few significant adverse events, and they are generally less frequent and less severe than those with TCAs. An additional attribute of moclobemide seems also to be its beneficial effect on cognitive functions.

Moclobemide and nortriptyline in elderly depressed patients. A randomized, multicentre trial against placebo

Moclobemide and nortriptyline were compared with placebo in a double-blind randomized multinational (Canada, Denmark and UK) trial comprising 109 patients of > 60 years of age with major depression (DSM-III-R). Patients were randomized to 7 weeks of treatment with doses of 400 mg/day moclobemide, 75 mg/day nortriptyline or placebo. It was necessary to adjust nortriptyline dosage in < 20% of patients to maintain serum levels within the postulated therapeutic window of 50-170 ng/ml. At end of treatment, the remission rates were 23% for moclobemide, 33% for nortriptyline and 11% for placebo. Anticholinergic and orthostatic events occurred more often with patients on nortriptyline than either moclobemide or placebo.

A Canadian multicentre placebo-controlled study of a fixed dose of brofaromine, a reversible selective MAO-A inhibitor, in the treatment of major depression

In a 6-week double-blind study, 220 patients with major depression (mostly outpatients) were randomly assigned to receive a fixed dose of brofaromine 150 mg daily (n = 111) or placebo (n = 109) after a 1-week single-blind placebo washout. Except for the HAM-D sleep items, brofaromine was superior to placebo on measures of depression as determined by the four methods of assessing drug efficacy: (1) psychiatric symptom rating (HAM-D 17-item less the three sleep items); (2) self-rating scale (Beck Depression Inventory); (3) Clinical Global Assessment of Efficacy; and (4) drop-out rate due to lack of efficacy. Most commonly reported adverse events with brofaromine were: headache, nausea, dizziness and sleep disturbance. Brofaromine was found to be an effective antidepressant, superior to placebo with a good tolerability profile.

Studies of a neurochemical link between depression, anxiety, and stress from [3H]imipramine and [3H]paroxetine binding on human platelets

We measured platelet [3H]imipramine and [3H]paroxetine binding in patients with major depression (n = 11), dysthymia (n = 9), generalized anxiety (n = 18) and panic disorder (n = 10), and in healthy controls (n = 13). The [3H]imipramine binding capacity (Bmax) was lower in all patient groups; [3H]paroxetine binding was reduced in anxiety disorders, however, decreases in depression and dysthymia were not significant. There were no differences in the affinity constant (Kd) for either radioligand. We also examined the effects of examination stress on platelet binding in medical students. Compared to after vacation, when binding was similar to controls, [3H]imipramine (n = 19) and [3H]paroxetine (n = 14) Bmax values were significantly decreased during examinations and similar to patient values. Examinations were also associated with an increase in plasma cortisol levels. These findings suggest that there is a neurochemical link between depression, anxiety, and stress, and that disturbances in neurochemical functioning may be associated with specific symptomatology, independent of psychiatric diagnosis.

Basal cortisol levels and cognitive deficits in human aging

A group of 19 healthy elderly subjects previously shown to differ in terms of their cortisol levels over a 4 year period were administered a neuropsychological test battery assessing memory, attention, and language. Correlational analyses performed on various corticosteroid measures showed that the slope of the change in cortisol levels over time predicted cognitive deficits in this elderly population. Aged subjects showing a significant increase in cortisol levels with years and with high current basal cortisol levels were impaired on tasks measuring explicit memory and selective attention when compared to aged subjects presenting either decreasing cortisol levels with years or increasing cortisol levels with moderate current basal cortisol levels. We further showed that subjects presenting a decrease in cortisol levels with years performed as well as young healthy subjects with regard to cognitive performance. Thus, impaired cognitive performance was associated with recent evidence of hypothalamic-pituitary-adrenal (HPA) dysregulation and elevated basal cortisol levels. These results are consistent with recent animal studies showing the existence of subpopulations of aged rats that differ in HPA activity and cognitive performance. Finally, the pattern of cognitive results related to the cortisol history of subjects is in agreement with a role played by the hippocampus in age-related HPA dysfunction and cognitive performance.

Biochemistry and pharmacology of reversible inhibitors of MAO-A agents: focus on moclobemide

Moclobemide, p-chloro-N-[morpholinoethyl]benzamide, is a prototype of RIMA (reversible inhibitor of MAO-A) agents. The compound possesses antidepressant efficacy that is comparable to that of tricyclic and polycyclic antidepressants. In humans, moclobemide is rapidly absorbed after a single oral administration and maximum concentration in plasma is reached within an hour. It is moderately to markedly bound to plasma proteins. MAO-A inhibition rises to 80% within two hours; the duration of MAO inhibition is usually between eight and ten hours. The activity of MAO is completely reestablished within 24 hours of the last dose, so that a quick switch to another antidepressant can be safely undertaken if clinical circumstances demand. RIMAs are potent inhibitors of MAO-A in the brain; they increase the free cytosolic concentrations of norepinephrine, serotonin and dopamine in neuronal cells and in synaptic vesicles. Extracellular concentrations of these monoamines also increase. In the case of moclobemide, increase in the level of serotonin is the most pronounced. Moclobemide administration also leads to increased monoamine receptor stimulation, reversal of reserpine induced behavioral effects, selective depression of REM sleep, down regulation of beta-adrenoceptors and increases in plasma prolactin and growth hormone levels. It reduces scopolamine-induced performance decrement and alcohol induced performance deficit which suggest a neuroprotective role. Tyramine potentiation with moclobemide and most other RIMA agents is negligible.

A comparison of the cardiac safety and therapeutic efficacy of trimipramine versus doxepin in geriatric depressed patients

OBJECTIVE

To compare the cardiac safety and therapeutic efficacy of trimipramine and doxepin.

DESIGN

A 1-week single-blind placebo period followed by a 5-week randomized double-blind parallel group clinical trial.

SETTING

Psychiatric out-patient clinic of a general hospital.

PATIENTS

37 young-elderly patients with a diagnosis of Major Depressive Episode (DSM-III criteria).

INTERVENTIONS

Placebo for 1 week, 2 weeks of titration with either drug in the dosage range of 75 mg/day up to a maximum of 200 mg/day.

MEASUREMENTS

We measured the psychiatric effects with the Hamilton Rating Scale for Depression, the Hamilton Anxiety Rating Scale, and the Clinical Global Impression Scale. Cardiovascular effects were assessed on 12-lead standard electrocardiograms plus 1-minute rhythm and high speed recordings; orthostatic (lying/standing) blood pressures were also taken. Physical exams, lab tests, cognitive functions (Buschke Selective Reminding Test, Hierarchic Dementia Scale, Word Fluency) and adverse reactions were also noted.

RESULTS

Both drugs were equally effective in relieving symptoms of depression and anxiety. The cardiovascular effects of both drugs were minimal. Trimipramine did lower blood pressure but this was without clinical significance. Three trimipramine patients and five doxepin patients developed occasional premature ventricular or atrial contractions. Of these, two trimipramine patients and one doxepin patient were among those with abnormal ECG's at entry. The doxepin patient was withdrawn from the study after 21 days of treatment when the PVC's became increasingly frequent.

CONCLUSIONS

Trimipramine and doxepin are equally safe and effective antidepressants in the young-elderly.

Levomepromazine receptor binding profile in human brain--implications for treatment-resistant schizophrenia

The receptor binding profile of levomepromazine (LMP) in human brain was compared with that of clozapine (CLOZ) and chlorpromazine (CPZ). LMP showed significantly greater binding affinity for both alpha-1 and serotonin-2 binding sites than either CLOZ or CPZ, and significantly greater binding to alpha-2 sites than CPZ. A potent pharmacological effect at these receptor sites may explain the beneficial effect of LMP on psychotic symptoms and akathisia in treatment-resistant schizophrenia recently described in 2 open studies. LMP requires further appraisal as a potentially useful neuroleptic in the management of treatment-resistant schizophrenia.

Glucocorticoid receptor gene expression is unaltered in hippocampal neurons in Alzheimer's disease

Excessive glucocorticoid levels increase the metabolic vulnerability of hippocampal neurons to a wide variety of insults. Since glucocorticoid hypersecretion occurs in Alzheimer's-type dementia it has been proposed that a primary reduction in hippocampal glucocorticoid receptor expression leads to failure of feedback, hypercortisolemia and hence further neuronal loss. However, we have recently found that lesions of the cholinergic innervation of the hippocampus--known to be severely affected in Alzheimer's disease--increase corticosteroid receptor gene expression in the rat hippocampus. We have now examined both glucocorticoid (GR) and mineralocorticoid (MR) receptor gene expression in individual neurons in human postmortem hippocampus, using in situ hybridization histochemistry in 5 patients with Alzheimer's disease (81 +/- 3 years) and 7 controls (81 +/- 7 years) without neurological disease. The distribution and intensity of MR and GR mRNA expression in the hippocampus of Alzheimer's disease were similar to that in control tissue, with high expression in dentate gyrus and CA2-4, but significantly lower expression in CA1. In a separate group of patients with Alzheimer's disease we found significantly increased 24 h integrated plasma cortisol levels (59% greater than age-matched controls) and reduced cortisol-binding globulin (21% lower). These data do not suggest a primary deficiency of biosynthesis of hippocampal corticosteroid receptors in Alzheimer's disease. The maintenance of hippocampal GR and MR gene expression, in the face of an increased glucocorticoid feedback signal, may reflect loss of the cholinergic innervation.

A 10-year follow-up study of tardive dyskinesia

In a 10-year follow-up study of 44 patients with tardive dyskinesia (TD), the majority (22 or 50%) had no change in their TD severity, 9 (20%) had an improvement and 13 (30%) had a worsening of their TD. Little difference was noted in those patients whose medication was decreased (n = 12) and those whose medication remained unchanged (n = 32). Of the women, 26% showed improvement as compared with 11% of the men. Also, patients whose TD improved had lower present neuroleptic dose than those whose TD worsened. These two factors should be studied in larger patient cohorts.

Is levomepromazine a useful drug in treatment-resistant schizophrenia?

Levomepromazine (LMP) unexpectedly improved 16 of 23 chronic treatment-resistant schizophrenic patients who were hospitalized in most cases for at least 2 years and who manifested positive symptoms, irritability and, in many cases, restlessness, hostility, uncooperativeness, poor concentration and aggressive behavior. Improvement led to discharge in 7 (6 to a foster home), placement on a waiting list for a foster home in 4 and improved behavior and autonomy in 5 patients. Five subjects developed seizures and 1 agranulocytosis. Whether improvement with LMP is caused by unique antischizophrenic properties or by diminished liability to induce side effects such as akathisia, a formal controlled study of LMP in treatment-resistant schizophrenia is merited.

Stereospecificity of the dopamine receptor mediating the growth hormone response to apomorphine in man. Short communication

The stereospecificity of the D-2 receptor mediating the growth hormone (GH) response to apomorphine (Apo) and the D-2 receptor regulating prolactin (PRL) secretion were investigated in 10 normal men by examining the effects of cis-flupenthixol (cis-Fx) and trans-flupenthixol (trans-Fx). cis-Fx (1 mg six hourly times four doses) antagonized the GH response to Apo HCl (0.5 mg sc) and increased basal serum PRL concentrations whereas the trans-isomer showed no effect. These findings (a) provide further evidence that the GH response to Apo is mediated by stimulating dopamine (DA) receptors, and, (b) demonstrate stereospecificity of the DA receptor mediating the GH response to Apo and the DA receptor regulating PRL secretion.

Localization of cholecystokinin binding sites in canine brain using quantitative autoradiography

1. CCK receptors have been characterized and localized in various mammalian species and significant species-specific differences in their distribution have been identified. In the present study, we report the first autoradiographic localization of CCK binding sites in the canine brain. 2. High densities of [125I]BH-CCK-8 binding sites were found in the cortex, cerebellum, hippocampus, caudate nucleus, olfactory bulb and nucleus accumbens. Moderate densities were present in the putamen, amygdala, and substantia gelatinosa. Low binding densities were observed in the globus pallidus, inferior colliculus, hypothalamus and thalamus. 3. Although the distribution profile of CCK binding sites in canine brain is similar to those previously reported in the rodent, primate and human brain, notable differences were observed in the hippocampus, cortex and cerebellum.

The effect of methyltestosterone on the growth hormone response to the dopamine receptor agonist, apomorphine

1. There is some evidence that androgens affect dopaminergic function in animals and man. We investigated the effect of methyltestosterone (MT) (30 mg po) on the growth hormone (GH) response to the dopamine (DA) receptor agonist, apomorphine (Apo) HC1 (0.5 mg sc), in 9 normal men. MT was given 2 hr before Apo. 2. The peak plasma MT concentration was present 1 hr after administration (19.9 +/- 19.5 ng/ml; X +/- SD); the concentration at 4 hr was 7.2 +/- 4.9 ng/ml. At the time of Apo administration, plasma MT varied from 6.0-24.1 ng/ml. 3. There was no significant effect of MT on Apo-GH secretion (interaction F(7,56) = 1.08; p = NS). The mean individual peak GH concentration after Apo alone was 20.2 +/- 11.9 (X +/- SD) vs 22.2 +/- 9.9 ng/ml when MT preceded Apo (p = NS). 4. These results suggest that exogenous androgens do not affect DA receptor function in males with normal androgenic function. Lack of effect due to an insufficient dose or duration of administration of MT cannot be excluded.

Factors in the development of severe forms of tardive dyskinesia

The authors evaluated 558 patients for tardive dyskinesia. They found that the prevalence of tardive dyskinesia was 34%. There were no differences between men and women in prevalence of tardive dyskinesia. However, severe tardive dyskinesia was found to occur more in male patients 40 years old or younger and in female patients 71 years old or older. Patients with mild tardive dyskinesia received more neuroleptics than did patients with moderate and severe forms. However, patients with moderate tardive dyskinesia had significantly more drug-free periods in their drug histories than did patients with mild tardive dyskinesia.

A controlled dose-ranging study of remoxipride and haloperidol in schizophrenia--a Canadian multicentre trial

The efficacy and side-effect profile for three dose ranges of remoxipride were compared with haloperidol in 242 schizophrenic inpatients in 13 centres. All patients were in a productive phase of schizophrenia according to DSM-III criteria. Relative efficacy of low dose (30-90 mg daily) vs middle dose (120-240 mg daily) vs high dose (300-600 mg daily) was compared with the standard dose of haloperidol (15-45 mg daily), as were the side effects. It was concluded that the therapeutic efficacy of remoxipride was comparable to that of haloperidol for acute episodes of schizophrenia; that the low dose range was significantly less effective than the higher ranges; that there was a clear advantage of remoxipride over haloperidol with respect to incidence and severity of extrapyramidal symptoms. The general safety profile of remoxipride as assessed from clinical chemistry, haematology, and cardiovascular variables suggests that remoxipride in the dose ranges studied can be used safely for the treatment of schizophrenic patients.

A dose-range finding study of zopiclone in insomniac patients

Sixty insomniac patients participated in a controlled double-blind parallel group study designed to investigate the dose-response relationship of zopiclone. Following 1 day of treatment with placebo, patients were randomly assigned to 1 of 6 groups and received treatment for 7 days with either placebo, or flurazepam 30 mg, or zopiclone, 3.75 mg, 7.5 mg, 11.25 mg or 15 mg. Four patients were dropped from the study; two from the placebo group due to ineffectiveness and one each in zopiclone 11.25 mg and 15 mg groups due to side-effects. Flurazepam 30 mg significantly improved sleep induction and maintenance by comparison to placebo and was indistinguishable from zopiclone 7.5 mg or higher. Results of a self-administered sleep questionnaire found a predominantly linear relationship between the dose of zopiclone administered and the degree of sleep improvement. The greatest increment in improvement was generally obtained with 3.5 mg and 7.5 mg of zopiclone, with some additional benefit occurring with zopiclone 11.25 mg. Clinicians' global impressions showed that the severity of illness clearly decreased in a dose related manner up to zopiclone 11.25 mg. Although zopiclone was well tolerated at 3.75 mg and 7.5 mg, an increase in side-effects occurred at 11.25 mg and 15 mg, which favours the use of 7.5 mg zopiclone as the optimum dose for most patients, although certain patients may benefit from a higher dose of the drug when well tolerated.

Effect of some peptides on dopaminergic function in man

Thyrotropin-releasing hormone (TRH) (200 micrograms iv) and 1-desamino-8-D-arginine vasopressin (DDAVP) (4 micrograms iv) antagonized the growth hormone (GH) response to apomorphine HCl (Apo) (0.5 mg sc) in 10 normal men. Apo had no effect on basal prolactin (PRL) levels but antagonized the PRL response to TRH. DDAVP plus Apo decreased PRL compared to placebo or DDAVP alone. These observations are compatible with (a) an inhibitory effect of TRH on hypothalamic and pituitary lactotrophe dopamine (DA) function (b) a facilitory effect of DDAVP on lactotrophe DA function and an inhibitory effect on hypothalamic DA function. Whether these are direct or indirect effects on DA mechanisms is unclear.

Neurochemical and receptor theories of depression

The neurochemical and receptor theories relate depression to deficient neurotransmission at critical sites in the brain. While this concept has generated a number of theories of depression over the years, the research findings do not fully support any single theory in its entirety. Several issues thus remain controversial or inconclusive. For instance, the monoamine deficit theory is supported by low urinary MHPG in some forms of bipolar, but not unipolar depression. Cerebrospinal fluid MHPG and 5-HIAA studies are inconclusive. Amine metabolite research is also limited in scope because the information derived pertains to pre-synaptic and synaptic events and ignores post-synaptic events. Receptor research, which includes study of both pre-and post-synaptic sites, suggests supersensitivity of Beta-adrenergic receptors in depression. But this research is criticized because it is mostly animal based. Also, the findings of low melatonin in depression contradict the supersensitivity-hypothesis. Abnormally low post-synaptic alpha-2 adrenoceptors is indicated by findings of an attenuated GH response to clonidine. But abnormality of pre-synaptic alpha-2 adrenoceptor functions has not been demonstrated conclusively. Recent findings in depression suggest a dysregulation in the dynamic and interactive relationship between neurotransmitters and receptors. Accordingly, a comprehensive view of the abnormalities of the various neurotransmitter systems in depression requires studies which investigate pre- and post-synaptic events simultaneously, preferably during illness and remission.

Effect of lithium and neuroleptic combination on lithium transport, blood pressure, and weight in bipolar patients

Patients treated with a combination of lithium (Li) and neuroleptics are reported to be at greater risk for toxicity. Previous findings suggested that treatment with a combination of Li and neuroleptics would increase the lithium ratio (LR) and intraerythrocyte Li levels. We studied 67 bipolar patients who were treated with Li alone (20 patients) or Li combined with haloperidol (17 patients), or Li combined with chlorpromazine (30 patients). Results revealed that the neuroleptic groups showed significantly lower LR and intracellular Li concentration as compared with those on Li alone. There was no significant difference in Li dosage among these three groups. No difference was found among these three groups with respect to mean blood pressure and weight. The number of hypertensive patients in the Li only group was twice as high as that in either of the two other groups, and the LR of the former was significantly higher than those of the latter groups.

Growth hormone response to apomorphine, a dopamine receptor agonist, in normal aging and in dementia of the Alzheimer type

The growth hormone (GH) response to the dopamine (DA) receptor agonist, apomorphine HCl (Apo) (0.5 mg SC) was studied in young and elderly normal subjects as well as in patients with dementia of the Alzheimer type (DAT) and controls matched for age, gender and Quetelet index. The GH response was significantly decreased in normal elderly men (mean age 67.3 years; N = 16) compared with young men (mean age 21.2 years; N = 12) and in elderly women (mean age 65.4 years; N = 9) compared with young women (mean age 25.5 years; N = 6) in the luteal phase but not in the early follicular phase. Young men had a significantly greater GH response than young women in either phase of the menstrual cycle. The decline in GH response with normal aging may be related to a decrease in sex steroid activity. There was no significant difference in GH response between DAT patients (N = 15) and paired controls. This suggests that hypothalamic D2 receptor function regulating GH secretion is not altered in DAT.