The Experts below are selected from a list of 36 Experts worldwide ranked by ideXlab platform
Bo Eriksson - One of the best experts on this subject based on the ideXlab platform.
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An open clinical and biochemical study of ritanserin in acute patients with schizophrenia
Psychopharmacology, 1994Co-Authors: Frits-axel Wiesel, A. -l. Nordström, L. Farde, Bo ErikssonAbstract:The effect of the selective Serotonin-2 Antagonist ritanserin was investigated in an open study of patients with schizophrenia. The patients were in an acute psychotic state considered to require neuroleptic medication. No neuroleptic drug was allowed during the study or during the last month preceeding the study. Oxazepam or nitrazepam were allowed for sedation or sleep inducement. Safety, tolerability, potential antipsychotic effect, and drug effects on monoamine metabolites in serum and CSF and prolactin in serum were evaluated. Central D_2-dopamine receptor occupancy was determined by positron emission tomography. Ten male patients (mean age 32.4) fulfilling DSM-III-R criteria for schizophrenia were included in the study. Nine of these patients completed 4 weeks' treatment with ritanserin 10 mg b.i.d. The clinical effect was evaluated by means of CPRS and SANS and significant improvement was seen after 4 weeks' treatment both in positive and negative symptoms. Ritanserin was well tolerated and no extrapyramidal symptoms or akathisia were seen. Concentrations of monoamine metabolites and prolactin did not change during treatment. Ritanserin did not occupy D_2-dopamine receptors. Thus, no indications of any D_2-dopamine-Antagonistic activity were obtained. All patients had expected ritanserin levels in plasma during the whole study. This first study of a selective Serotonin-2 Antagonist in the treatment of acute schizophrenic patients demonstrated significant clinical effects. However, the open design of the study does not allow us to conclude with any certainty that the patients' improvement was due to a specific blockade of Serotonin-2 receptors or unspecific factors, although a direct D_2-dopamine blockade could be ruled out.
Frits-axel Wiesel - One of the best experts on this subject based on the ideXlab platform.
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An open clinical and biochemical study of ritanserin in acute patients with schizophrenia
Psychopharmacology, 1994Co-Authors: Frits-axel Wiesel, A. -l. Nordström, L. Farde, Bo ErikssonAbstract:The effect of the selective Serotonin-2 Antagonist ritanserin was investigated in an open study of patients with schizophrenia. The patients were in an acute psychotic state considered to require neuroleptic medication. No neuroleptic drug was allowed during the study or during the last month preceeding the study. Oxazepam or nitrazepam were allowed for sedation or sleep inducement. Safety, tolerability, potential antipsychotic effect, and drug effects on monoamine metabolites in serum and CSF and prolactin in serum were evaluated. Central D_2-dopamine receptor occupancy was determined by positron emission tomography. Ten male patients (mean age 32.4) fulfilling DSM-III-R criteria for schizophrenia were included in the study. Nine of these patients completed 4 weeks' treatment with ritanserin 10 mg b.i.d. The clinical effect was evaluated by means of CPRS and SANS and significant improvement was seen after 4 weeks' treatment both in positive and negative symptoms. Ritanserin was well tolerated and no extrapyramidal symptoms or akathisia were seen. Concentrations of monoamine metabolites and prolactin did not change during treatment. Ritanserin did not occupy D_2-dopamine receptors. Thus, no indications of any D_2-dopamine-Antagonistic activity were obtained. All patients had expected ritanserin levels in plasma during the whole study. This first study of a selective Serotonin-2 Antagonist in the treatment of acute schizophrenic patients demonstrated significant clinical effects. However, the open design of the study does not allow us to conclude with any certainty that the patients' improvement was due to a specific blockade of Serotonin-2 receptors or unspecific factors, although a direct D_2-dopamine blockade could be ruled out.
L. Farde - One of the best experts on this subject based on the ideXlab platform.
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An open clinical and biochemical study of ritanserin in acute patients with schizophrenia
Psychopharmacology, 1994Co-Authors: Frits-axel Wiesel, A. -l. Nordström, L. Farde, Bo ErikssonAbstract:The effect of the selective Serotonin-2 Antagonist ritanserin was investigated in an open study of patients with schizophrenia. The patients were in an acute psychotic state considered to require neuroleptic medication. No neuroleptic drug was allowed during the study or during the last month preceeding the study. Oxazepam or nitrazepam were allowed for sedation or sleep inducement. Safety, tolerability, potential antipsychotic effect, and drug effects on monoamine metabolites in serum and CSF and prolactin in serum were evaluated. Central D_2-dopamine receptor occupancy was determined by positron emission tomography. Ten male patients (mean age 32.4) fulfilling DSM-III-R criteria for schizophrenia were included in the study. Nine of these patients completed 4 weeks' treatment with ritanserin 10 mg b.i.d. The clinical effect was evaluated by means of CPRS and SANS and significant improvement was seen after 4 weeks' treatment both in positive and negative symptoms. Ritanserin was well tolerated and no extrapyramidal symptoms or akathisia were seen. Concentrations of monoamine metabolites and prolactin did not change during treatment. Ritanserin did not occupy D_2-dopamine receptors. Thus, no indications of any D_2-dopamine-Antagonistic activity were obtained. All patients had expected ritanserin levels in plasma during the whole study. This first study of a selective Serotonin-2 Antagonist in the treatment of acute schizophrenic patients demonstrated significant clinical effects. However, the open design of the study does not allow us to conclude with any certainty that the patients' improvement was due to a specific blockade of Serotonin-2 receptors or unspecific factors, although a direct D_2-dopamine blockade could be ruled out.
A. -l. Nordström - One of the best experts on this subject based on the ideXlab platform.
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An open clinical and biochemical study of ritanserin in acute patients with schizophrenia
Psychopharmacology, 1994Co-Authors: Frits-axel Wiesel, A. -l. Nordström, L. Farde, Bo ErikssonAbstract:The effect of the selective Serotonin-2 Antagonist ritanserin was investigated in an open study of patients with schizophrenia. The patients were in an acute psychotic state considered to require neuroleptic medication. No neuroleptic drug was allowed during the study or during the last month preceeding the study. Oxazepam or nitrazepam were allowed for sedation or sleep inducement. Safety, tolerability, potential antipsychotic effect, and drug effects on monoamine metabolites in serum and CSF and prolactin in serum were evaluated. Central D_2-dopamine receptor occupancy was determined by positron emission tomography. Ten male patients (mean age 32.4) fulfilling DSM-III-R criteria for schizophrenia were included in the study. Nine of these patients completed 4 weeks' treatment with ritanserin 10 mg b.i.d. The clinical effect was evaluated by means of CPRS and SANS and significant improvement was seen after 4 weeks' treatment both in positive and negative symptoms. Ritanserin was well tolerated and no extrapyramidal symptoms or akathisia were seen. Concentrations of monoamine metabolites and prolactin did not change during treatment. Ritanserin did not occupy D_2-dopamine receptors. Thus, no indications of any D_2-dopamine-Antagonistic activity were obtained. All patients had expected ritanserin levels in plasma during the whole study. This first study of a selective Serotonin-2 Antagonist in the treatment of acute schizophrenic patients demonstrated significant clinical effects. However, the open design of the study does not allow us to conclude with any certainty that the patients' improvement was due to a specific blockade of Serotonin-2 receptors or unspecific factors, although a direct D_2-dopamine blockade could be ruled out.
R A Glennon - One of the best experts on this subject based on the ideXlab platform.
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A three-lever operant procedure differentiates the stimulus effects of R(-)-MDA from S(+)-MDA.
Journal of Pharmacology and Experimental Therapeutics, 1996Co-Authors: Richard Young, R A GlennonAbstract:1-(3,4-Methylenedioxyphenyl)-2-aminopropane (MDA) produces an effect in humans that is somewhat similar to both a hallucinogen and a central stimulant. We have previously shown that R(-)-MDA but not S(+)-MDA produces a stimulus effect in animals similar to that of the hallucinogen 1-(2,5-dimethoxy-4-methylphenyl)-2-aminopropane (DOM), whereas S(+)-MDA but not R(-)-MDA produces a stimulus effect similar to that of the stimulant amphetamine. Others have suggested that the stimulus effects of the two MDA isomers may be much more similar than our results would indicate. To help clarify this issue, we have shown that rats (n = 8) can be trained to discriminate 1.25 mg/kg of R(-)-MDA (ED50 = 0.99 mg/kg) from 1.25 mg/kg of S(+)-MDA (ED50 = 0.80 mg/kg) versus 0.9% saline with use of a three-lever operant procedure. To accomplish this task it was necessary to institute a separation of 4 days between injections of the isomers. In tests of stimulus substitution, the administration of various doses of DOM (ED50 = 0.47 mg/kg), S(+)-DOM (ED50 = 2.23 mg/kg) and mescaline (ED50 = 16.04 mg/kg) produced dose-related responding on the R(-)-MDA-appropriate lever. In contrast, the injection of various doses of S(+)-amphetamine (ED50 = 0.46 mg/kg) and cocaine (ED50 = 6.40 mg/kg) produced dose-related responding on the S(+)-MDA-appropriate lever. The administration of racemic MDA, at twice the isomer training dose, resulted in the animals dividing their responses closely between the R(-)-MDA- and S(+)-MDA-designated levers. In antagonism tests, the Serotonin-2 Antagonist pirenperone blocked the stimulus effect of 1.25 mg/kg of R(-)-MDA but had no effect on the stimulus effect of 1.25 mg/kg of S(+)-MDA. Taken together, these data support the contention that each optical isomer of MDA can produce a markedly different stimulus effect.
