[Determination of the binding of perazine and perazine sulfoxide to human serum albumin].
Explore the source record for details and available documents.
Antipsychotic Agents↗
SEARCH · Search PubMed
Results for “Perazine”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
The effect of selective serotonin reuptake inhibitors (SSRIs) on the pharmacokinetics and metabolism of perazine in the rat.
The aim of this study was to investigate the effect of three selective serotonin reuptake inhibitors (SSRIs), fluoxetine, fluvoxamine and sertraline, on the pharmacokinetics and metabolism of perazine in a steady state in rats. Perazine (10 mg kg(-1), i.p.) was administered twice daily for two weeks, alone or jointly with one of the SSRIs. Concentrations of perazine and its two main metabolites (N-desmethylperazine and 5-sulfoxide) in the plasma and brain were measured 30 min and 6 and 12 h after the last dose of the drugs. Of the investigated SSRIs, fluoxetine and fluvoxamine significantly increased plasma and brain concentrations of perazine (up to 900% and 760% of the control value, respectively), their effect being most pronounced after 30 min and 6 h. Moreover, simultaneous increases in perazine metabolites concentrations and in the perazine/metabolite concentration ratios were observed. Sertraline elevated plasma and brain concentrations of perazine after 30 min. In-vitro studies with liver microsomes of rats treated chronically with perazine, SSRIs ortheir combinations showed decreased concentrations of cytochrome P-450 after perazine and a combination of perazine and fluvoxamine (vs control), and increased concentration after a combination of perazine and fluoxetine (vs perazine-treated group). Prolonged treatment with perazine did not significantly change the rate of its own metabolism. Chronic administration of fluoxetine or sertraline, alone or in a combination with perazine, accelerated perazine N-demethylation (vs control or perazine group, respectively). Fluvoxamine had a similar effect. The 5-sulfoxidation of perazine was accelerated by fluvoxamine and sertraline treatment, but the process was inhibited by administration of a combination of perazine and fluoxetine or fluvoxamine (vs control). Kinetic studies using control liver microsomes, in the absence or presence of SSRIs added in-vitro, demonstrated competitive inhibition of both N-demethylation and sulfoxidation by the investigated SSRIs. Sertraline was the most potent inhibitor of perazine N-demethylation but the weakest inhibitor of sulfoxidation. Results of in-vivo and in-vitro studies indicate that the observed interaction between perazine and SSRIs mainly involves competition for an active site of perazine N-demethylase and sulfoxidase. Moreover, increases in the concentrations of both perazine and metabolites measured, produced by the investigated drug combinations in-vivo, suggest simultaneous inhibition of another, yet to be investigated, metabolic pathway of perazine (e.g. aromatic hydroxylation).
Animals↗
Different effects of amitriptyline and imipramine on the pharmacokinetics and metabolism of perazine in rats.
The aim of this study was to search for possible effects of imipramine and amitriptyline on the pharmacokinetics and metabolism of perazine at steady state in rats. Perazine (10 mg kg(-1), i.p.) was administered to rats twice daily for two weeks, alone or jointly with imipramine or amitriptyline (10 mg kg(-1) i.p.). Concentrations of perazine and its two main metabolites (5-sulphoxide and N-desmethylperazine) in the plasma and brain were measured at 30 min (Cmax), 6h and 12h (slow disposition phase) after the last dose of the drugs. Liver microsomes were prepared 24 h after withdrawal of the drugs. Amitriptyline increased the plasma and brain concentrations of perazine (up to 300% of the control) and N-desmethylperazine, while not affecting those of 5-sulphoxide. Imipramine only tended to increase the neuroleptic concentration in the plasma and brain. Studies with control liver microsomes showed that amitriptyline and imipramine added to the incubation mixture in-vitro, competitively inhibited N-demethylation (Ki (inhibition constant) = 16 microM and 164 microM, respectively) and 5-sulphoxidation (Ki = 57 microM and 86 microM, respectively) of perazine, amitriptyline being a more potent inhibitor of perazine metabolism, especially with respect to N-demethylation. Studies with microsomes of rats treated chronically with perazine or tricyclic antidepressants, or both, did not show significant differences in the rate of perazine metabolism between perazine- and perazine+antidepressant-treated rats. The data obtained were compared with the results of analogous experiments with promazine and thioridazine. It was concluded that elevations of perazine concentration were caused by direct inhibition of the neuroleptic metabolism by the antidepressants. Similar interactions, possibly leading to exacerbation of the pharmacological action of perazine, may be expected in man. Since the interactions between phenothiazines and tricyclic antidepressants may proceed in two directions, reduced doses of both the neuroleptic and the antidepressant are recommended when the drugs are administered jointly.
Amitriptyline↗
Perazine for schizophrenia.
BACKGROUND: Perazine is an old phenothiazine derivative used for the treatment of people with schizophrenia which has a reputed low level of extrapyramidal side-effects. However, its use is restricted in the sense that - to the best knowledge of the reviewers - it is only marketed in Germany, Poland, Yugoslavia and the Netherlands. OBJECTIVES: To examine the effects of perazine for those with schizophrenia, and schizophrenia-like psychoses. SEARCH STRATEGY: Electronic searches of the Cochrane Schizophrenia Group's register which includes relevant randomised controlled trials from the bibliographic databases Biological Abstracts, CINAHL, The Cochrane Library, EMBASE, MEDLINE, PsycLIT, LILACS, PSYNDEX, Sociological Abstracts and Sociofile were undertaken. References of all included studies were searched for further trials. Pharmaceutical companies and authors of trials were contacted. SELECTION CRITERIA: All randomised controlled trials that compared perazine with other treatments for people with schizophrenia and/or schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: Citations and, where possible, abstracts were independently inspected by two reviewers, papers ordered, re-inspected and quality assessed. Data were independently extracted. Data were excluded if loss to follow up was greater than 50%. For homogeneous dichotomous data the Relative Risk (RR), 95% confidence interval (CI) and, where appropriate, the number needed to treat (NNT) were calculated on an intention-to-treat basis. For continuous data, weighted mean differences were calculated (WMD). All data were inspected for heterogeneity. MAIN RESULTS: Six trials with a total of 288 participants are included. According to only one trial with 95 participants perazine appeared superior to active placebo (trimipramine) at five weeks for the outcome of 'no important global improvement' (n=95, RR 0.6, CI 0.3-0.9, NNT 4, CI 2-17), but there was no difference in various measures of mental state. The side-effect risk of perazine compared to placebo could not be estimated because they were not reported. Five small trials including only 193 participants which compared perazine with other antipsychotics were incompletely reported and the outcomes were presented in various ways so that meta-analysis was not possible in most occasions. A similar number of participants receiving perazine or comparator antipsychotics left the studies early (n=193, RR 0.9, CI 0.5-1.4). The results on efficacy were controversial and need further assessment by randomised controlled trials. No obvious differences in adverse events between perazine and other antipsychotics could be derived from these limited data. Two haloperidol comparisons did not present extrapyramidal side-effects in a way usable for meta-analysis, but three small comparisons with the atypical antipsychotics zotepine and amisulpride showed no higher risk of akathisia (n=111, RR 0.3, CI 0.1-1.1), dyskinesia (n=111, RR 0.5, CI 0.1-3.5), parkinsonism (n=81, RR 1.2, CI 0.5-2.8) or tremor (n=40, RR 0.8, CI 0.3-2.3) with perazine. REVIEWER'S CONCLUSIONS: The number, size and reporting of randomised controlled perazine trials is insufficient to present firm conclusions about the properties of this antipsychotic. It is possible that perazine is associated with a similar risk of extrapyramidal side-effects as some atypical antipsychotics, and this should be clarified in larger, well-designed trials.
Antipsychotic Agents↗
Perazine for schizophrenia.
BACKGROUND: Perazine is an old phenothiazine derivative used for the treatment of people with schizophrenia and is reputed to have a low level of extrapyramidal adverse effects. As far as we are aware, its use is limited to Germany, Poland, the former Yugoslavia and the Netherlands. OBJECTIVES: To examine the effects of perazine for those with schizophrenia, and schizophrenia-like psychoses. SEARCH STRATEGY: We searched the Cochrane Schizophrenia Group's register which includes relevant randomised controlled trials from the bibliographic databases Biological Abstracts, CINAHL, The Cochrane Library, EMBASE, MEDLINE, PsycLIT, LILACS, PSYNDEX, Sociological Abstracts and Sociofile (last update of the review March 2005). We searched references of all included studies for further trials. We contacted pharmaceutical companies and authors of trials. SELECTION CRITERIA: We selected all randomised controlled trials that compared perazine with other treatments for people with schizophrenia and/or schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: We independently (SL, BH) inspected citations and where possible abstracts and ordered papers for re-inspection and quality assessment. We independently extracted data. We excluded data if loss to follow up was greater than 50%. For homogeneous dichotomous data we calculated the Relative Risk (RR), 95% confidence interval (CI) and, where appropriate, the number needed to treat (NNT) on an intention-to-treat basis. For continuous data, we calculated weighted mean differences (WMD). We inspected all data for heterogeneity. MAIN RESULTS: We included six trials with a total of 288 participants. In only one trial with 95 participants, perazine appeared superior to 'active placebo' (trimipramine) at five weeks for the outcome of 'no important global improvement' (n=95, RR 0.43 CI 0.2 to 0.8, NNT 4 CI 2 to 13), but there was no statistically significant difference in most measures of mental state. Perazine did not induce more general adverse events than placebo, but more participants received at least one dose of antiparkinson medication (n=95, RR 4.50 CI 1.0 to 19.5, NNH 6 CI 4 to 33). Five small trials comparing perazine with other antipsychotics, including in total only 193 participants, were incompletely reported and the outcomes were presented in various ways so that meta-analysis was not possible in most occasions. A similar number of participants receiving perazine or comparator antipsychotics left the studies early (n=193, RR 0.85, CI 0.5 to 1.4). The results on efficacy were controversial and need further assessment by randomised controlled trials. No obvious differences in adverse events between perazine and other antipsychotics could be derived from the limited data. Two haloperidol comparisons did not present extrapyramidal side-effects in a suitable way for use in meta-analysis, but three small comparisons with the atypical antipsychotics zotepine and amisulpride showed no higher risk of akathisia (n=111, RR 0.31 CI 0.1 to 1.1), dyskinesia (n=111, RR 0.47 CI 0.1 to 3.5), parkinsonism (n=81, RR 1.21 CI 0.5 2.8) or tremor (n=40, RR 0.80 CI 0.3 to 2.6) with perazine. AUTHORS' CONCLUSIONS: The number, size and reporting of randomised controlled perazine trials is insufficient to present firm conclusions about the properties of this antipsychotic. It is possible that perazine is associated with a similar risk of extrapyramidal side-effects as some atypical antipsychotics, and this should be clarified in larger, well-designed trials.
Antipsychotic Agents↗
Distribution interactions between perazine and antidepressant drugs. In vivo studies.
Perazine belongs to the most frequently chosen neuroleptics for a combination with antidepressants in the therapy of complex or "treatment-resistant" psychiatric illnesses. The aim of the present study was to investigate the effect of the distribution interaction between perazine and antidepressants in vivo. Experiments were carried out on male Wistar rats. Animals received perazine and an antidepressant drug (imipramine or fluoxetine), separately or jointly, at a dose of 10 mg/kg ip. Concentrations of perazine, imipramine, fluoxetine and their metabolites in the blood plasma and tissues were measured at 1 h after administration of the drugs (HPLC). Effects of distribution interactions were estimated on the basis of the calculated tissue/plasma and lysosome-poor/lysosome-rich tissue concentration ratios, considering the heart and muscles as lysosome-poor and the lungs, liver and kidneys as lysosome-rich ones. Both imipramine and fluoxetine diminished the tissue/plasma concentration ratios of perazine for the lungs and kidneys (not for the liver), but elevated those ratios for the brain, muscles and heart. On the other hand, perazine lowered the lungs/plasma concentration ratio of both antidepressants and the liver/plasma concentration ratio of imipramine. Simultaneously, perazine elevated the brain/plasma and heart/plasma concentration ratios of both antidepressants. Consequently, the perazine concentration ratios of lysosome-poor/lysosome-rich tissue significantly increased in the presence of the investigated antidepressants, with an exception of the muscles/liver concentration ratio. At the same time, perazine raised the heart/lysosome-rich tissue concentration ratios of imipramine and fluoxetine, not changing significantly the muscles/lysosome-rich concentration ratios of the antidepressants. In conclusion, the presented results provide evidence that the observed in vitro distributive interactions between perazine and the antidepressants occur also in vivo, leading to a shift of the drugs from organs rich in lysosomes to those poor in these organella, in particular to the heart. Perazine and the antidepressants mutually increased the drug concentration ratios of heart/plasma and heart/lysosome-rich tissue, i.e. the heart/lung, heart/liver and heart/kidneys ratios. Similar results were obtained with lysosome-poor muscles in the case ofperazine. Moreover, the obtained results indicate that, apart from the lysosome density in the investigated tissues, the potential metabolic interactions in the liver and the order of drug circulation in a body have an important impact on the calculated drug concentration ratios.
Animals↗
Lysosomal trapping as an important mechanism involved in the cellular distribution of perazine and in pharmacokinetic interaction with antidepressants.
Perazine, a piperazine-type phenothiazine neuroleptic, is the most frequently chosen drug for combination with antidepressants in the therapy of complex or 'treatment-resistant' psychiatric illnesses. The aim of the present study was to investigate the contribution of lysosomal trapping to the total tissue uptake of perazine, and the pharmacokinetic interaction between the neuroleptic and antidepressants. Experiments were carried out on slices of different rat organs regarded as a system with functional lysosomes. To distinguish between lysosomal trapping and tissue binding, the experiments were performed in the absence or presence of 'lysosomal inhibitors', i.e. the lysosomotropic compound ammonium chloride or [H+] ionophore monensin, which abolish the pH-gradient of lysosomes. Under steady-state conditions, the highest tissue uptake of perazine was observed for the adipose tissue, which descended in the following order: the adipose tissue>lungs>liver>heart=brain>kidneys>muscles. The contribution of lysosomal trapping to the total tissue uptake amounted to about 40% in the liver, brain and muscles, to 30% in the kidneys, and to 25% in the heart and lungs. In the adipose tissue, no lysosomotropism of perazine was observed. Of the psychotropics studied, perazine was the only drug showing such a high degree of lysosomal trapping in muscles and distinct lysosomotropic properties in the heart. Perazine and the antidepressants used, both tricyclic (imipramine, amitriptyline) and selective serotonin reuptake inhibitors (fluoxetine, sertraline), mutually decreased their tissue uptake. The potency of imipramine to decrease perazine uptake was similar to that of the 'lysosomal inhibitors'. Other antidepressants seemed to exert a somewhat weaker effect. The above interactions between perazine and antidepressants were not observed in the presence of ammonium chloride, which indicates that they proceeded at the level of lysosomal trapping. The adipose tissue in which the drug uptake was not affected by the 'lysosomal inhibitors' was not the site of such an interaction. Ammonium chloride did not affect the drug metabolism in liver slices; other tissues displayed only a negligible biotransformation of the psychotropics studied. A parallel metabolic interaction between perazine and tricyclic antidepressants took part in liver slices (i.e. perazine and antidepressants mutually inhibited their metabolic pathways), but the influence of such an interaction on the lysosomal uptake of the parent compounds in liver slices did not seem to be great. A substantial decrease in concentrations of the drugs in lysosomes (depot form) observed in vitro may lead to an increase in the concentration in vivo of the neuroleptic and antidepressants at the site of action, which, in turn, may increase the risk of cardiotoxic and anticholinergic side-effects of tricyclic antidepressants and sedative and extrapyramidal effects of the neuroleptic.
Ammonium Chloride↗
Prediction and evaluation criteria in perazine therapy of acute schizophrenics. Pharmacokinetic data.
Twenty-eight patients with acute schizophrenic illness received an oral daily dose of 200-800 mg perazine (Taxilan) for 4 weeks. Weekly plasma level determinations showed a constant perazine concentration from day 7 to day 28, whereas the equilibrium level of its metabolite desmethyl perazine was only achieved at day 14; on an average it amounted to twice the level of perazine. Additional measurements were carried out 2 and 4 h after administration of the morning dose on day 14. The maximal increase of the perazine concentration was usually reached after 2 h; though it varied between 7 and 240% of the morning level, a close correlation existed between minimal and maximal levels. The perazine fraction not bound to plasma proteins was found to be 3.1-5.5% on day 21. The percent improvement in target syndromes during 4 weeks of neuroleptic therapy, as documented with the AMDP system, was most marked in those patients who had perazine levels in the 100-230 ng/ml range at day 28; patients with lower or higher levels improved significantly less. Curvilinear relationships also appeared to exist between improvement and free perazine concentration as well as maximal level on day 14. With regard to total scores on the Brief Psychiatric Rating Scale or scores of higher-order factors, no significant relationship between improvement and perazine level was found. The desmethyl perazine concentration did not exhibit a significant relationship to the therapeutic result. The pharmacokinetic parameters investigated seem to have a limited influence on the clinical outcome.(ABSTRACT TRUNCATED AT 250 WORDS)
Acute Disease↗
Effects of cytochrome P-450 inducers on the perazine metabolism in a primary culture of human hepatocytes.
The metabolism of perazine in a primary culture of human hepatocytes after treatment of cells with TCDD (a CYP1A1/2 inducer) or rifampicin (mainly a CYP3A4 inducer) were studied in vitro. The concentrations of perazine and its main metabolites (perazine 5-sulfoxide, N-desmethylperazine) formed in hepatocytes were assayed in the extracellular medium using the HPLC method. TCDD and rifampicin induced the formation of perazine 5-sulfoxide, however, such an effect was not observed in the case of N-desmethylperazine. The accumulation of perazine 5-sulfoxide in the extracellular medium was enhanced until up to 4 h by rifampicin, and until up to 8 h byTCDD. After 24 h, perazine and perazine 5-sulfoxide were not detected in the extracellular medium of the inducer-treated cultures, except for perazine 5-sulfoxide in the TCDD-treated cultures The obtained results indicate that CYP1A2 and CYP3A4 are involved in the perazine metabolism via 5-sulfoxidation pathway.
Biotransformation↗
The metabolism of the piperazine-type phenothiazine neuroleptic perazine by the human cytochrome P-450 isoenzymes.
Identification of cytochrome P-450 isoenzymes (CYPs) involved in perazine 5-sulphoxidation and N-demethylation was carried out using human liver microsomes and cDNA-expressed human CYPs (Supersomes). In human liver microsomes, the formation of perazine metabolites correlated significantly with the level of CYP1A2 and ethoxyrezorufin O-deethylase activity, as well as with the level of CYP3A4 and cyclosporin A oxidase activity. Moreover, the formation of N-desmethylperazine also correlated well with S-mephenytoin 4'-hydroxylase activity (CYP2C19). alpha-Naphthoflavone (a CYP1A2 inhibitor) and ketoconazole (a CYP3A4 inhibitor) significantly decreased the rate of perazine 5-sulphoxidation, while ticlopidine (a CYP2C19 inhibitor) strongly reduced the rate of perazine N-demethylation in human liver microsomes. The cDNA-expressed human CYPs generated different amounts of perazine metabolites, but the preference of CYP isoforms to catalyze perazine metabolism was as follows (pmol of product/pmol of CYP isoform/min): 1A1>2D6>2C19>1A2>2B6>2E1>2A6 approximately 3A4>2C9 for 5-sulphoxidation and 2C19>2D6>1A1>1A2>2B6>3A4>2C9>2A6 for N-demethylation. In the light of the obtained results and regarding the contribution of each isoform to the total amount of CYP in human liver, it is concluded that CYP1A2 and CYP3A4 are the main isoenzymes catalyzing 5-sulphoxidation (32% and 30%, respectively), while CYP2C19 is the main isoform catalyzing perazine N-demethylation (68%). CYP2C9, CYP2E1 CYP2C19 and CYP2D6 are engaged to a lesser degree in 5-sulphoxidation, while CYP1A2, CYP3A4 and CYP2D6 in perazine N-demethylation (6-10%, depending on the isoform).
Adult↗
Monitoring of serum bioactivity levels of perazine and its metabolites by radioreceptor assay.
The bioactivity of perazine and its metabolites in human serum was analysed by radioreceptor assay. The IC50 value (the concentration eliciting a 50% blockade of 3H-spiroperidol binding to the dopamine receptor in a membrane suspension of porcine striatum) was for perazine 175 nmol/l, and for its metabolites perazine sulfoxide 1050 nmol/l, desmethylperazine 330 nmol/l, N-(3-phenothiazin-10-yl-propyl)-ethylenediamine 2800 nmol/l, and N-(3-phenothiazin-10-yl-propyl)-N'-methylethylenediamin 2850 nmol/l. Thus, perazine metabolites possess low affinity to the dopamine receptor. In a pilot study we measured the bioactivity of perazine and its metabolites in sera of perazine-treated psychiatric patients by radioreceptor assay and compared the results to levels obtained by high-performance thin-layer chromatography; the correlation coefficient r was 0.85 and the slope 0.95 (n = 11). Thus serum perazine can be adequately monitored by radioreceptor assay, as evidenced by the results from high-performance thin-layer chromatography.
Adolescent↗
[Changes in drug elimination under the influence of perazine therapy (author's transl)].
In 8 male patients who were treated with perazine for a schizophrenic psychosis (200-800 mg/die), the elimination rate of phenazone was investigated. Simultaneously determinations of plasma levels of perazine and desmethylperazine were carried out. The average half-life of phenazone was 27.0 h in perazine-treated patients and 11.2 h in controls. Correspondingly, the clearance of phenazone decreased from 47.0 ml/min to 18.9 ml/min under perazine, both differences being highly significant. The amount of 4-OH-phenazone, the principal hydroxylated metabolite excreted in the urine, was 66 mg/24 h in the perazine group, and significantly different from the results obtained in the control group: 185 mg/24 h. In contrast the urinary excretion of the unchanged phenazone increased from 29 to 40 mg/24 h under perazine. The results are interpreted to demonstrate inhibition of drug hydroxylation in the liver by perazine treatment.
Antipsychotic Agents↗
Cytochrome P-450 enzymes and FMO3 contribute to the disposition of the antipsychotic drug perazine in vitro.
RATIONALE: Perazine (PER) is a phenothiazine antipsychotic drug frequently used in Germany that undergoes extensive metabolism. OBJECTIVES AND METHODS: To anticipate metabolic drug interactions and to explore the relevance of polymorphisms of metabolic enzymes, perazine-N-demethylation and perazine-N-oxidation were investigated in vitro using human liver microsomes and cDNA expressed enzymes. RESULTS: CYP3A4 and CYP2C9 were identified as the major enzymes mediating PER-N-demethylation. At 10 microM PER, a concentration consistent with anticipated in vivo liver concentrations, CYP3A4 and CYP2C9 contributed 50% and 35%, respectively, to PER-N-demethylation. With increasing PER concentrations, contribution of CYP2C9 decreased and CYP3A4 became more important. In human liver microsomes, PER-N-demethylation was inhibited by ketoconazole (>40%) and sulfaphenazole (16%). Allelic variants of recombinant CYP2C9 showed differences in PER-N-demethylase activity. The wild type allele CYP2C9*1 was the most active variant. Maximal activities of CYP2C9*2 and CYP2C9*3 were 88% and 18%, respectively, compared to the wild type activity. Perazine-N-oxidation was mainly mediated by FMO3. In the absence of NADPH, heat treatment of microsomes abolished PER-N-oxidase activity. Methimazole inhibited PER-N-oxidation, while CYP specific inhibitors had no inhibitory effect. Perazine is a potent inhibitor of dextromethorphan-O-demethylase, S-mephenytoin-hydroxylase, alprazolam-4-hydroxylase, phenacetin-O-deethylase and tolbutamide-hydroxylase activity in human liver microsomes. CONCLUSIONS: Alterations in the activity of CYP3A4, CYP2C9 and FMO3 through genetic polymorphisms, enzyme induction or inhibition bear the potential to cause clinically significant changes in perazine clearance. PER may alter the clearance of coadministered compounds metabolized by CYP2D6, CYP2C19, CYP2C9, CYP3A4 and CYP1A2.
Antipsychotic Agents↗
Possible mutagenicity of the psychoactive phenothiazine derivative perazine in vivo and in vitro.
Human lymphocyte cultures from 55 schizophrenic subjects and one manic-depressive subject being treated with the phenothiazine derivative perazine and with other drugs were analyzed with respect to chromosomal damage. The frequency of exchange-type aberrations in these subjects was more than double that in clinically normal control subjects. No correlation was detectable between the aberration frequency and sex, age, smoking and drinking habits, and treatment conditions. It is possible that the elevation of the chromosomal aberration frequency is due to perazine. In vitro studies with perazine and two main metabolites (desmethylperazine and perazine sulfoxide) with human lymphocytes and CHO cells with and without metabolic activation by liver microsomes gave negative results with respect to the induction of sister chromatid exchanges. Possible differences in the metabolism of perazine in vivo and in vitro are discussed.
Adolescent↗
Effect of chronic treatment with perazine on lipopolysaccharide-induced interleukin-1 beta levels in the rat brain.
In the present study, we sought to determine whether chronic treatment with perazine alters lipopolysaccharide (LPS)-induced interleukin-1 beta (IL-1 beta) levels in the following rat brain regions: the hypothalamus, frontal cortex, striatum and hippocampus. Male Wistar rats were administered perazine dimaleate (15 or 30 mg/kg/day) in drinking water for 21 days. On day 22, LPS was injected i.p. (125 microg/kg) 2 h before decapitation. Concentrations of perazine and its metabolites in plasma and brain was assessed by HPLC. The levels of IL-1 beta were determined using ELISA. Treatment with perazine (30 mg/kg/day) reduced LPS-stimulated IL-1 beta levels in the hypothalamus, and a tendency to its decrease in the striatum and frontal cortex was observed. This in vivo study suggests for the first time that long-term oral administration of perazine modulates reactivity of cells producing IL-1 beta.
Animals↗
Antipsychotic efficacy of the antidepressant trimipramine: a randomized, double-blind comparison with the phenothiazine perazine.
BACKGROUND: The tricyclic antidepressant trimipramine exhibits several features (e. g., dopaminergic effect, molecular structure similar to a neuroleptic, receptor-binding profile similar to clozapine) that suggest its potential as an antipsychotic medication. The aim of the study was to investigate the antipsychotic potential of trimipramine in a controlled clinical trial comparing its antipsychotic efficacy with that of a neuroleptic. METHOD: In a German multi-center, randomized, double-blind trial, the antipsychotic efficacy of trimipramine was compared with that of the phenothiazine neuroleptic perazine, using the Brief Psychiatric Rating Scale (BPRS), the Positive and Negative Syndrome Scale (PANSS), and Clinical Global Impressions (CGI). Antidepressant efficacy of both agents was measured by use of the Bech-Rafaelsen Melancholia Scale (BRMES). Ninety-five patients with acute schizophrenia (DSM-III-R) and a BPRS total score > 40 at baseline were treated with either 300-400 mg trimipramine or 450-600 mg perazine for 5 weeks. RESULTS: Therapeutic equivalence of both treatments (in the dosages used) could not be demonstrated (change in BPRS total score, per-protocol [PP] analysis, one-sided equivalence testing). However, intention-to-treat (ITT) as well as PP analysis showed a statistically significant decrease in the BPRS total scores in both treatment groups (PP: trimipramine, 56.5 +/- 9.8 to 44.1 +/- 17.9; perazine, 56.4 +/- 10.8 to 37.9 +/- 12.9). Significant decreases in all BPRS and PANSS subscores as well as CGI results and response rate support the antipsychotic efficacy of trimipramine. The BRMES total scores significantly decreased in both treatment groups without showing a significant difference between the two agents. Trimipramine was better tolerated than perazine and did not elicit extrapyramidal symptoms. CONCLUSION: Trimipramine failed to exhibit therapeutic equivalence to perazine in the dosages used. However, there was evidence of a substantial antipsychotic effect of trimipramine. It may be a useful medication if depressive symptoms in psychotic patients require antidepressant treatment or if other antipsychotics cannot be administered.
Antidepressive Agents↗
[Zotepine versus perazine in patients with paranoid schizophrenia: a double-blind controlled trial of its effectiveness].
The dibenzothiepine zotepine is a new potential "atypical" neuroleptic exhibiting powerful antiserotonergic and antidopaminergic properties. The efficacy of zotepine was evaluated in a double-blind controlled trial versus the tricyclic neuroleptic perazine in 41 patients suffering mainly from the paranoid-hallucinatory type of schizophrenia. The key outcome variable was the extent of mental disturbance as defined by the total score of the BPRS. Additional outcome variables were GAS and CGI. In addition, adverse reactions and extrapyramidal side effects were assessed according to the FSUCL scale and the Gerlach and AIMS rating scale, respectively. Additional variables recorded were blood pressure, heart rate and routine laboratory parameters as well as electrocardiogram and electroencephalogram. In the first two days, standard equivalent doses of both drugs were administered. Thereafter, doses were administered as required. The efficacy of both substances was compared after 7, 14 and 28 days of treatment. Both drugs showed a similar antipsychotic efficacy. Under zotepine treatment a 55% improvement of the BPRS total score was observed while perazine led to a 41% BPRS score reduction. After 7 days the zotepine group was significantly more improved than the perazine group, possibly due to a dosing effect in the perazine group. In the zotepine group, fewer adverse reactions and a better benefit/risk index were observed although the differences between the two treatment groups did not reach levels of statistical significance. There were no drug-specific abnormal laboratory findings. Thus, in the present study there was no significant difference between zotepine and perazine with respect to antipsychotic efficacy and side-effect rates. However, zotepine showed a trend to a better benefit/risk index at the end of treatment.
Adult↗
Perazine as a potent inhibitor of human CYP1A2 but not CYP3A4.
The effects of perazine on the activities of CYP1A2 and CYP3A4 in a primary culture of human hepatocytes of one patient were studied in vitro. The CYPs activities were assessed by measuring the rate of acetanilide 4-hydroxylation (CYP1A2) and cyclosporine A oxidation (CYP3A4) after treatment with TCDD (a CYP1A subfamily inducer) or rifampicin (mainly a CYP3A4 inducer). The amounts of the metabolites formed in hepatocytes were assayed in the extracellular medium using the HPLC method. TCDD and rifampicin induced the formation of 4-hydroxyacetanilide and cyclosporine A metabolites (monohydroxycyclosporine A, dihydroxycyclosporine A, N-desmethylcyclosporine A), respectively. The formation of 4-hydroxyacetanilide was strongly inhibited by three different concentrations of perazine (10, 25 and 50 microM) reaching 8, 3 and 2% of the control value, respectively. In the case of CYP3A4 activity, no such an effect of perazine was observed. Perazine showed only a week inhibition of the activity of cyclosporine A oxidase (to 96-86% of the control value). The obtained results suggest a strong inhibitory effect of perazine on human CYP1A2 activity with predicted Ki value similar to those of the known for CYP1A2 inhibitors, such as furafylline and fluvoxamine.
Acetanilides↗