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Biomedical subjects

O Benkert

Publications and source records attributed to O Benkert.

At least 55 records · Page 3Linked to original sources
PubMed1996

Effects of yohimbine on sexual experiences and nocturnal penile tumescence and rigidity in erectile dysfunction.

The therapeutic effect of the alpha 2-antagonist yohimbine in erectile dysfunction was studied in a double-blind placebo-controlled design. Thirty-one male patients underwent extensive clinical, urological, and psychiatric diagnosis and were dichotomically classified into an organic and a nonorganic subgroup. Following a 1-week placebo run-in period, patients were randomly assigned to a placebo or a verum group (yohimbine 15 mg daily) for a treatment period of 7 weeks. The Clinical Global Impression (CGI) scale was used as the primary efficacy parameter. Additionally, nocturnal penile tumescence and rigidity (NPTR) were measured. Global assessment of erectile function applying the CGI scale revealed, beyond a placebo effect in both organic and nonorganic patients, a therapeutic effect in the subgroup of nonorganic patients, with a significantly greater improvement in the yohimbine group compared to the placebo group. No superiority of yohimbine compared to placebo was found in the organic patients. These findings on the subjective level had no correlate in the NPTR recordings. The NPTR parameters were unchanged under yohimbine treatment in both the nonorganic and organic subgroup. No interrelation was found between subjective improvement and NPTR alterations. Polysomnographic control of the NPTR registrations ensured that the duration of REM sleep under treatment was not influenced.

Adult↗
PubMed1996

Acute, subchronic and discontinuation effects of zopiclone on sleep EEG and nocturnal melatonin secretion.

Zopiclone is a new short half-life cyclopyrrolone hypnotic agent acting at the GABA-benzodiazepine receptor complex. In order to characterize its pharmacological profile, the effects of 7.5 mg zopiclone on nocturnal melatonin secretion were investigated under polysomnographic control in 11 healthy subjects following acute and subchronic administration as well as after abrupt discontinuation of the drug. No effect of zopiclone on the melatonin plasma levels could be observed. Regarding both total melatonin production and the temporal pattern of melatonin secretion during the night, there was no difference between placebo baseline condition, acute and subchronic administration, and discontinuation. In contrast, the sleep EEG data demonstrated the hypnotic efficacy of zopiclone under acute administration and indicated a rebound insomnia after abrupt discontinuation. Moreover, alterations of sleep architecture were found under treatment as well as after discontinuation. Whereas, with regard to sleep EEG parameters, zopiclone appears to be comparable with some short-acting benzodiazepines, a discrepancy between the missing effect of zopiclone on pineal function and the suppressing influence of benzodiazepines known from the literature becomes obvious. The fact that zopiclone does not interfere with nocturnal melatonin secretion at pharmacologically active doses as indicated by alterations in sleep EEG parameters might possibly point to a pharmacodynamic difference between the two drug classes.

Adult↗
PubMed1996

Psychopharmacological drugs as represented in the press: results of systematic analysis of newspapers and popular magazines.

The representation of mental diseases and psychopharmacological drugs in the media, especially in the press, is thought to be of great impact on people's opinions on the subject. During the course of one year, all articles about psychopharmacological drugs and cardiac drugs published in nineteen German newspapers were collected. All statements, together with related aspects, reasons for prescription, individual details of the patient, effects and side-effects, were registered and classified according to a key. The results show that, in contrast to 13% of the articles about cardiac drugs, half of the reports about psychopharmacological drugs deal primarily with the problems of side-effects and dependence the drugs may produce. There was much more critical comment and emotional emphasis used to characterize the psychopharmacological drugs. Only in 9% of articles was their therapeutic efficacy mentioned. Cardiac drugs are generally discussed objectively in a medical context and in 53% efficacy is emphasized. Psychopharmacological drugs are often mentioned in stories about prominent persons having a life crisis, taking drugs, turning to alcoholism, or in the context of social decline. Only in 3% of all articles about psychopharmacological drugs was it possible to identify a serious mental disease as the reason for prescription. The reasons for and implications of these findings, which mainly reflect the negatively biased image of psychopharmacological drugs in women's magazines (while they are treated relatively fairly in general newspapers) are discussed.

Cardiovascular Agents↗
PubMed1996

Subchronic antidepressant treatment with venlafaxine or imipramine and effects on blood pressure and heart rate: assessment by automatic 24-hour monitoring.

Venlafaxine is a new nontricyclic antidepressant inhibiting the reuptake of serotonin, noradrenaline, and, to a lesser extent, dopamine without antagonizing cholinergic, histaminergic, or noradrenergic receptors. Significantly, in a first placebo-controlled safety and efficacy study, high doses of venlafaxine increased blood pressure in some study subjects. In order to investigate further the effect of subchronic antidepressant drug treatment on blood pressure and heart rate, the effects of a conventional tricyclic (imipramine) and a structurally different phenethylamine antidepressant (venlafaxine) were compared. Sixteen inpatients with major depression (melancholic type) were treated for six weeks with imipramine or venlafaxine in a randomized parallel double-blind design. Blood pressure was monitored for 24 hours before treatment and at days 14 and 28 by means of a portable, automatic blood-pressure monitoring system. Both compounds lowered systolic blood pressure by about 5% on average, while diastolic pressure was influenced neither by imipramine nor by venlafaxine. Imipramine treatment resulted in a significant 15% increase in heart rate on both day 14 and day 28, whereas heart rate tended to decrease under venlafaxine. When the data of individual patients were evaluated, a clinically significant increase in blood pressure was apparent in one venlafaxine-treated patient; a marked increase in blood pressure in one patient treated with imipramine proved to be reversible with continued treatment. Due to the relatively small sample sizes, the present data do not allow a definitive judgement as to whether venlafaxine may cause differential blood pressure alterations in comparison with imipramine. However, our results demonstrate that the blood pressure-increasing effect reported for venlafaxine from first clinical studies might be clinically significant in individual patients. Furthermore, our study shows that 24-hour monitoring of blood pressure and heart rate is a powerful tool in safety evaluations of new drugs, even in relatively small samples.

Adult↗
PubMed1996

Minimum effective dose for antidepressants--an obligatory requirement for antidepressant drug evaluation?

Extensive clinical trials are required for registration and approval of new antidepressants in most countries including the requirement that a minimal effective dose should be determined. The rationale for this requirement is to avoid the use of unnecessarily high doses. The implication is that for every antidepressant, a dose exists that serves as a threshold, below which all doses are not effective or are clearly less effective in treating a major depressive episode. Dose titration and fixed dose studies are used to determine the minimal effective dose, but both strategies have limitations and often do not allow definite establishment of a clear-cut minimal effective dose. The effort of establishing a minimal effective dose for registration is expensive and time-consuming, and may not be beneficial. Variations in pharmacokinetics and other important factors are likely to confound the results of studies and impair the determination of efficacy. The consequence of these confounding variables may be the need for larger patient samples in clinical trials or separate studies with sufficient sample sizes controlling for these variables. However, this raises issues of practicality and cost. For several newer and most older antidepressants, a minimal effective dose has not been established. Nevertheless, most antidepressants in clinical practice are safe and well tolerated. Methodologically sound establishment of a minimal effective dose raises ethical problems, as large numbers of patients need to be treated with expectedly ineffective doses. From several methodological, clinical and ethical considerations, it would seem unnecessary to establish a minimal effective dose for an effective and well-tolerated new antidepressant.

Antidepressive Agents↗
PubMed1996

[Psychiatric diseases and their treatment in general practice in Germany. Results of a World Health Organization (WHO) study].

As part of an international study initiated by the World Health Organization (WHO) about psychological disorders in primary health care, patients in the Federal Republic of Germany were compared with patients in other European centres. Patients from Germany do not differ from other European patients in respect to sociodemographic variables or psychiatric disorders. The most frequent CIDI-based diagnoses recorded in patients attending general practices are current depressive episodes (8.6%), generalized anxiety disorders (8.5%), neurasthenia (7.5%), and alcohol dependence (6.3%). In 20.9% of the patients at least one psychiatric diagnosis based on ICD-10 was recorded. In Germany significantly lower global ratings of health status are given than in other European centres although there is no difference in diagnostic prevalence rates. The recognition rate, i.e. the agreement between the CIDI-based ICD-10 diagnoses and the recognition as a case by the physician, is 56.2%-60.2%. On the other hand, the CIDI detects 90% of the patients described as psychologically ill by the physicians if subthreshold cases are also counted, or 46.4% if only defined diagnoses are taken into account. There is a significant correlation between severity of the psychiatric disorder and disability in social functioning. In Mainz and in the other European countries the disability rate of patients with a well-defined disorder is between 67.0% and 72.7%, whereas in Berlin this relation is not as clear, because especially in East Berlin there is a higher rate of unemployment in view of the political situation. Drug treatment is prescribed for 16.1% of the patients in primary care for psychiatric disorders. Half the patients recognized by physicians as cases receive medication. In the rest of Europe patients receive significantly more tranquillizers than in Germany, where the use of herbal drugs is more wide spread.

Adult↗
PubMed1995

Seroquel (ICI 204 636), a putative "atypical" antipsychotic, in schizophrenia with positive symptomatology: results of an open clinical trial and changes of neuroendocrinological and EEG parameters.

Preclinical data indicated that seroquel (ICI 204 636), a dibenzothiazepine with 5-HT2 and D2-like receptor antagonistic properties, might be an effective antipsychotic agent, causing fewer extrapyramidal side effects than typical neuroleptics. In the present study, 12 patients suffering from schizophrenia or schizophreniform disorder with predominantly positive symptomatology were treated in an open clinical trial for 4 weeks with seroquel at a maximum dosage of 750 mg/day. The drug was generally well tolerated, and virtually no adverse extrapyramidal side effects such as acute dystonia, parkinsonism or akathisia were observed. Total scores for BPRS (item score 0-6; baseline: 42.0 +/- 2.3; mean +/- SEM), SAPS (64.5 +/- 4.8) and SANS (55.0 +/- 4.3) showed a moderate decrease at the end of treatment (BPRS: 30.0 +/- 3.5; SAPS: 36.1 +/- 6.7; SANS: 42.5 +/- 5.9), when intention-to-treat analysis was applied. There were considerable interindividual differences in treatment response, with some subjects showing almost full remission of positive symptoms, in contrast to about half of the patients who showed no satisfactory clinical improvement. Interestingly, patients showing good antipsychotic response reported slight initial side effects like mild sedation. Prolactin and TSH levels were not altered during seroquel administration. As to pharmaco-EEG investigations, seroquel caused a moderate increase of the absolute power in the alpha, theta, and beta frequency bands, paralleled by a decrease of delta activity. There were no signs of paroxysmal EEG activity under seroquel.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

The neuroendocrinological profile of roxindole, a dopamine autoreceptor agonist, in schizophrenic patients.

Roxindole is a potent autoreceptor-selective dopamine agonist with additional properties as a serotonin reuptake inhibitor and 5-HT1A agonist. In order to get more insight into its mode of action in various psychiatric populations, we evaluated the effects of subchronic roxindole treatment on pituitary and adrenal hormone secretion, i.e. release of prolactin, thyroid stimulating hormone (TSH), growth hormone (GH), luteinizing hormone (LH), and cortisol. Fifteen schizophrenic patients with positive and negative symptomatology, respectively, were treated with roxindole for 28 days. Both basal and thyrotropin releasing hormone (TRH) -induced prolactin secretion diminished significantly to 26.4% and 22.8% of baseline levels, respectively, under roxindole. Basal GH secretion was insignificantly elevated by 89%, whereas GH levels increased nearly 3-fold after stimulation by TRH. TSH levels decreased insignificantly to 57.5% of baseline levels, while TRH-induced TSH release was not affected by subchronic roxindole. Roxindole treatment influenced neither LH secretion nor cortisol release. Our results indicate that roxindole's dopaminergic actions might prevail over its serotonergic effects, at least as far as the regulation of anterior pituitary hormone secretion is concerned.

Adult↗
PubMed1995

Dopamine agonists in schizophrenia: a review.

Although it is unlikely that the different types of course and severity of schizophrenia are caused by one neurochemical abnormality alone, indirect pharmacological evidence still suggests a relative excess of dopaminergic activity being implicated in the pathogenesis of most of the schizophrenic symptoms, e.g. positive symptomatology. Synthesis and release of dopamine as well as firing rates of dopaminergic neurons are controlled by stimulation of autoreceptors via a negative feedback regulation. Investigations on therapeutic effects of autoreceptor-nonselective dopamine agonists in schizophrenia have yielded inconsistent results. Dopamine autoreceptor agonists like pramipexole, roxindole, talipexole and OPC-4392 as well as partial agonists like terguride and SDZ HDC 912 have been tested in positive schizophrenic symptomatology in order to reduce the postulated excess of central dopaminergic activity. However, administration of autoreceptor-'selective' agonists did not result in a significant improvement of positive symptoms. In predominantly negative schizophrenic symptomatology, a dopamine deficit rather than an excess has been hypothesized. Consequently, a nonselective dopamine agonistic action could be effective in some negative symptoms. Current evidence from several open and one placebo-controlled clinical trial suggests that some dopamine autoreceptor agonists like pramipexole, roxindole and talipexole may produce a mild improvement of symptoms like affective flattening, depressed mood, alogia and avolition. Nevertheless, these findings do not yet allow a reliable judgement and remain to be clarified by further double-blind placebo-controlled studies over a sufficient treatment duration.

Antipsychotic Agents↗
PubMed1995

Effects of corticotropin-releasing hormone on respiratory parameters during sleep in normal men.

Corticotropin-releasing hormone (CRH) is well-known to be a centrally acting respiratory stimulant after systemic application both in healthy subjects and in patients suffering from respiratory failure. In order to study the effects of CRH on sleep EEG and respiratory parameters during sleep, 14 healthy male volunteers were investigated in a single-blind placebo controlled design. After an adaptation night, polysomnography was performed during two successive nights between 23.00 hrs. and 7.00 hrs. During one night placebo was applied, on the other 50 micrograms ovine CRH was administered intravenously as a bolus every hour from 0.00 hrs. to 6.00 hrs. For the assessment of respiration, blood oxygen saturation and thoracic wall movements were measured, as well as nasal and oral airflow using the thermistor method. Sleep efficiency parameters and subjective perception of sleep quality were not affected following CRH. The following alterations were found regarding sleep architecture: REM sleep as well as slow wave sleep showed a tendency to decrease under CRH, whereas light sleep tended to increase. After an injection of CRH a stimulation of respiration could be observed, with an increase of tidal volume over a time interval of a few minutes. Blood oxygen saturation was only slightly increased. Cortisol and ACTH concentrations were found to be constantly elevated. These results indicate that respiration during sleep is clearly affected by CRH with only slight alterations of global sleep parameters. No association was found between stimulation of ventilation and the occurrence of arousals; the respiratory analeptic effect of CRH thus appears to be specific.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1995

[Psychopharmaceutical drugs in the mass media. Results of a systematic analysis of text contents and images].

Mental diseases and psychopharmacological drugs are frequently discussed in newspapers and popular magazines. The representations are supposed to have a great impact on people's opinions on the subject. From 1 August 1991 to 31 July 1992 all articles about psychopharmacological drugs and cardiac drugs in 19 German newspapers were collected. All statements, effects and side effects, the reason for prescription, individual details about the patient and, according to this procedure, subjects and implications of the illustrations, were registered and classified according to a code book. In contrast to the articles about cardiac drugs, half of the psychopharmacological drug reports primarily deal with the problems of side effects the drugs may produce. There was much more critical comment and emotional emphasis used to characterize the psychopharmacological drugs. Only in 9% was their therapeutic efficacy mentioned. Cardiac drugs are generally discussed objectively in a medical context and their efficacy is emphasized. Psychopharmacological drugs are often mentioned in stories about prominent persons having a life crisis, taking drugs, or turning to alcoholism, in the sense of social decline. In only 3% of these articles could a serious mental diseases be identified as the reason for the prescription. Corresponding to the more prominent emotional emphasis of these articles, compared to the articles about cardiac drugs, more pictures, mainly of prominent persons or patients are used. However, the illustration seldom adds to information provided. The reasons for and implications of these findings and the significant differences between the distinct groups of newspapers are discussed.

Cardiovascular Agents↗
PubMed1994

Brief depression among patients in general practice. Prevalence and variation by recurrence and severity.

Depression with substantial psychosocial impairment, but not qualifying as depressive disorder according to the standard diagnostic manuals, is frequent among primary care patients. Recurrent brief depression (RBD) is a diagnostic category intended to identify a major proportion of this group of patients. The WHO study on "Psychological Problems in Primary Health Care" was used as a vehicle to estimate the proportion of patients with this diagnosis and to evaluate the validity of this diagnosis as well as of alternative concepts of brief depression with multiple episodes. This study applies a two-stage sampling scheme; 300 patients also underwent an additional interview tailored for variants of brief depression. 7.6% of primary care patients were identified as RBD with the majority not receiving any other psychiatric diagnosis (DSM-III-R). These patients reported substantial psychosocial impairment, and the majority were identified as psychological cases by general practitioners. However, patients experiencing other variants of brief episodes were also found to be substantially psychosocially impaired, although they were not identified as psychiatric cases by DSM-III-R. Thus, a less restrictive definition of RBD is proposed. The diagnostic definition of RBD has a major impact on the sex ratio of cases: the less restrictive the diagnosis, the more balanced are the prevalence rates between males and females.

Adolescent↗
PubMed1994

Recurrent brief depression in general practice. Clinical features, comorbidity with other disorders, and need for treatment.

This study tested the clinical validity of the new diagnostic entity "recurrent brief depression" (RBD) in 300 general practice patients who participated in the WHO study on "Psychological Problems in Primary Care." Patients with current RBD reported of episodes major depression more often than did a comparison group of nondepressed general practice patients: however, the majority of RBD patients had not received a diagnostic of any well-established affective disorder during the last 12 months. RBD patients (without MDE) did not suffer more frequently from dysthymia, from nonaffective psychiatric disorders, or from somatic disorders. However, RBD was associated with a higher percentage of previous suicide attempts and of ideation of suicide and death. RBD was accompanied by substantial psychosocial impairment; psychosocial impairment in RBD patients could not be explained by excess comorbidity. Thus, the clinical validity of RBD was demonstrated although doubts about the appropriateness of the definition remained. This new diagnostic category needs more attention as only as small minority of patients with RBD received specific antidepressant treatment.

Activities of Daily Living↗
PubMed1994

Treatment of chronic depression with sulpiride: evidence of efficacy in placebo-controlled single case studies.

Systematic variation of treatment (alternating active drug and placebo in four treatment periods) in individual patients is proposed to collect preliminary evidence for a therapeutic effect of sulpiride in chronic depression; the ARIMA model is applied to evaluate the intervention effects of the tentatively effective treatment in single subjects. Ten single cases of chronic depression with a diagnosis of major depression or dysthymia were selected and seven of these provided evidence for beneficial effects of sulpiride with regard to treating the symptoms of depression and anxiety. However, the drug effects were intraindividually not always replicable. The results obtained with these single cases positively support the recommendation to perform regular randomized placebo-controlled trials with sulpiride in chronic depression. Simultaneously, these single case investigations reveal a lack of temporal stability of treatment response and inconsistencies of response with regard to different treatment targets in individual patients.

Adult↗
PubMed1994

Decreased benzodiazepine receptor binding in panic disorder measured by IOMAZENIL-SPECT. A preliminary report.

Single photon emission tomography (SPECT) imaging of the central benzodiazepine receptor (BZr) became possible with the newly developed ligand 123I-IOMAZENIL. The BZr binding was investigated in ten patients with panic disorder (PP) compared to ten epileptic patients (EP). Panic patients had lower IOMAZENIL uptake rates in the frontal, occipital and temporal cortex than EP indicating the involvement of the BZr complex in panic disorder.

Adult↗
PubMed1994

Subtypes of negative symptoms: the primary subtype in schizophrenic and non-schizophrenic patients.

1. The specificity of negative symptoms remains an open question and requires further research. 2. Subtyping negative symptoms has been showed to be a very relevant point for the identification of primary negative symptoms and for their pharmacotherapy. Negative symptoms as a whole have been demonstrated in schizophrenic and non-schizophrenic patients, but these studies did not report about the primary and secondary subtypes. 3. The present study is the first one investigating primary negative symptoms in schizophrenic and non-schizophrenic patients. 84 consecutively admitted psychiatric patients have been studied 5 years after their discharge. 4. All negative symptoms (including the primary subtype) according to Carpenter (Kirkpatrick et al. 1989) and Andreasen (Andreasen 1981) could be identified in all diagnostic groups.

Female↗