Clinical evaluation of sulpiride in schizophrenic patients--a double-blind comparison with chlorpromazine

Biomarkers in the cerebrospinal fluid of patients with psychotic disorders compared to healthy controls: a systematic review and meta-analysis

Psychotic disorders are severe mental disorders with poorly understood etiology. Biomarkers in the cerebrospinal fluid (CSF) could provide etiological clues and diagnostic tools for psychosis; however, an unbiased overview of CSF alterations in individuals with psychotic disorders is lacking. The objective of this study was to summarize all quantifiable findings in CSF from individuals with psychotic disorders compared to healthy controls (HC). Studies published before January 25th, 2023 were identified searching PubMed, EMBASE, Cochrane Library, Web of Science, ClinicalTrials.gov, and PsycINFO. Screening, full-text review, data extraction, and risk of bias assessments were performed by two independent reviewers following PRISMA guidelines. Findings in patients and healthy controls were compared and summarized using random-effects analyses and assessment of publication bias, subgroup and sensitivity analyses were performed. 145 studies, covering 197 biomarkers, were included, of which 163 biomarkers have not previously been investigated in meta-analyses. All studies showed some degree of bias. 55 biomarkers measured in CSF were associated with psychosis and of these were 15 biomarkers measured in ≥2 studies. Patients showed increased levels of noradrenaline (standardized mean difference/SMD, 0.53; 95% confidence interval/CI, 0.16 to 0.90) and its metabolite 3-methoxy-4-hydroxyphenylglycol (SMD, 0.30; 95% CI: 0.05 to 0.55), the serotonin metabolite 5-hydroxyindoleacetic acid (SMD, 0.11; 95% CI: 0.01 to 0.21), the pro-inflammatory neurotransmitter kynurenic acid (SMD, 1.58; 95% CI: 0.34 to 2.81), its precursor kynurenine (SMD,0.99; 95% CI: 0.60 to 1.38), the cytokines interleukin-6 (SMD, 0.58; 95% CI: 0.39 to 0.77) and interleukin-8 (SMD, 0.43; 95% CI: 0.24 to 0.62), the endocannabinoid anandamide (SMD, 0.78; 95% CI: 0.53 to 1.02), albumin ratio (SMD, 0.40; 95% CI: 0.08 to 0.72), total protein (SMD, 0.29; 95% CI: 0.16 to 0.43), immunoglobulin ratio (SMD, 0.45; 95% CI: 0.06 to 0.85) and glucose (SMD, 0.48; 95% CI: 0.01 to 0.94). Neurotensin (SMD, -0.67; 95% CI: -0.89 to -0.46) and γ-aminobutyric acid (SMD, -0.29; 95% CI: -0.50 to -0.09) were decreased. Most biomarkers showed no significant differences, including the dopamine metabolites homovanillic acid and 3,4-dihydroxyphenylacetic acid. These findings suggest that dysregulation of the immune and adrenergic system as well as blood-brain barrier dysfunction are implicated in the pathophysiology of psychotic disorders.

A systematic microdialysis study of dopamine transmission in the accumbens shell/core and prefrontal cortex after acute antipsychotics

RATIONALE

The only systematic in vivo studies comparing antipsychotic (AP) effects on nucleus accumbens (NAc) shell and core dopamine (DA) transmission are voltammetric studies performed in pargyline-pretreated, halothane-anaesthetized rats. Studies in freely moving rats not pretreated with pargyline are not available. This study was intended to fill this gap by the use of in vivo microdialysis in freely moving rats.

METHODS

Male Sprague-Dawley rats were implanted with microdialysis probes in the NAc shell and core and medial prefrontal cortex (PFCX). The next day, rats were administered intravenously with two or three doses of APs, and dialysate DA was monitored in 10-min samples. Some rats were pretreated with pargyline (75 mg/kg i.p.) and after 1 h were given clozapine or risperidone.

RESULTS

Clozapine, risperidone, quetiapine, raclopride, sulpiride and amisulpride increased DA preferentially in the NAc shell. Such preferential effect on shell DA was not observed after haloperidol, chlorpromazine and olanzapine. In contrast to voltammetric studies, a preferential effect on NAc core DA was not observed after any dose of AP. Pargyline pretreatment did not reduce but actually amplified the preferential effect of clozapine and risperidone on NAc shell DA.

CONCLUSIONS

Apart from raclopride and olanzapine, the APs with lower extrapyramidal effects could be distinguished from typical APs on the basis of their ability to preferentially stimulate DA transmission in the NAc shell. There was no relationship between stimulation of PFCX DA and atypical APs profile. The differences between this study and voltammetry studies were not attributable to pargyline pretreatment.

Placebo response in antipsychotic clinical trials: a meta-analysis

IMPORTANCE

Because increasing placebo response rates decrease drug-placebo differences and increase the number of failed trials, it is imperative to determine what is causing this trend.

OBJECTIVES

To investigate the relationship between antipsychotic medication and placebo response by publication year, and to identify associated study design and implementation variables.

DATA SOURCES

MEDLINE, PsycINFO, and PubMed were searched to identify randomized clinical trials of antipsychotic medications published from 1960 to July 2013.

STUDY SELECTION

Included were randomized clinical trials lasting 4 to 24 weeks, contrasting antipsychotic medication with placebo or an active comparator, and enrolling patients 18 years of age or older with schizophrenia or schizoaffective disorder.

DATA EXTRACTION AND SYNTHESIS

Standardized mean change scores were calculated for each treatment arm, plotted against publication year, and tested with Spearman rank correlation coefficients. Hierarchical linear modeling identified factors associated with the standardized mean change across medication and placebo treatment arms.

MAIN OUTCOMES AND MEASURES

We hypothesized that the mean change in placebo-treated patients would significantly increase from 1960 to the present, that a greater change would be observed in active comparator vs placebo-controlled trials, and that more protocol visits would increase the symptom change observed.

RESULTS

In the 105 trials examined, the mean change observed in placebo arms increased significantly with year of publication (n=39, r=0.52, P=.001), while the mean change in effective dose medication arms decreased significantly (n=208, r=-0.26, P<.001). Significant interactions were found between assignment to effective dose medication and publication year (t260=-5.55, P<.001), baseline severity (t260=5.08, P<.001), and study duration (t260=-3.76, P<.001), indicating that the average drug-placebo difference significantly decreased over time, with decreasing baseline severity and with increasing study duration. Medication treatment in comparator studies was associated with significantly more improvement than medication treatment in placebo-controlled trials (t93=2.73, P=.008).

CONCLUSIONS AND RELEVANCE

The average treatment change associated with placebo treatment in antipsychotic trials increased since 1960, while the change associated with medication treatment decreased. Changes in randomized clinical trials leading to inflation of baseline scores, enrollment of less severely ill participants, and higher expectations of patients may all be responsible.

Sulpiride adjunction to clozapine in treatment-resistant schizophrenic patients: a preliminary case series study

Six chronic neuroleptic-resistant schizophrenic patients, partial responders to clozapine, were co-administered 600 mg/day of sulpiride (a selective D(2) dopaminergic antagonist) as an augmentation to clozapine (a relatively weak D(2) blocker), for 10 weeks, open-labeled. A remarkable reduction in positive and negative symptoms was observed in four of the six patients.

Outcome study of first-episode schizophrenia in a developing country: quality of life and antipsychotics

AIM

Quality of life has recently been emphasized in the management of schizophrenia, yet data from developing country is lacking. We explored the differences in subjective quality of life between conventional antipsychotics (CAs) and atypical antipsychotics (AAs).

METHODS

This is a naturalistic study conducted in Kuala Lumpur, Malaysia. Patients with first-episode schizophrenia and related psychosis were recruited from Kuala Lumpur Hospital. WHOQOL-BREF, side effects of medications and other variables were assessed after 1 year of treatment in routine clinical situation.

RESULTS

The study comprised 120 adults. There were no significant statistical differences between groups concerning subjective quality of life, extrapyramidal side effects and employment. Significant less benzhexol usage was reported among AAs (P<0.001) compared to CAs and sulpiride.

CONCLUSION

Patients treated with CAs, sulpiride or AAs experienced similar quality of life, clinical and health outcomes after 1 year commencing treatment. Overall, the results are in line with other major pragmatic clinical trials. This study also found sulpiride cost-effective.

Cerebrospinal fluid kynurenic acid in male patients with schizophrenia - correlation with monoamine metabolites

BACKGROUND

The tryptophan metabolite kynurenic acid (KYNA) is an endogenous glutamate/nicotinic receptor antagonist. Previous studies have shown that the concentration of the compound is increased in cerebrospinal fluid (CSF) of patients with schizophrenia. Furthermore, it has been found that the CSF concentration of KYNA is positively correlated to CSF concentrations of the monoamine metabolites homovanillic acid (HVA) and 5-hydroxy indoleacetic acid (5-HIAA) in healthy control subjects.

OBJECTIVES

To study the correlations between KYNA and the monoamine metabolites HVA, 5-HIAA and 4-hydroxy-3-methoxyphenylglycol (HMPG) in CSF of male patients (n= 53, ranging from 20 to 48 years of age) with verified schizophrenia.

METHODS

CSF was obtained by lumbar puncture, and KYNA analysis was performed with an isocratic reversed-phase high-performance liquid chromatography system connected to a fluorescence detector. HVA, 5-HIAA and HMPG concentrations were measured by mass fragmentography with deuterium-labelled internal standards.

RESULTS

Positive intercorrelations were found between CSF KYNA, HVA and 5-HIAA, while CSF content of HMPG did not correlate to KYNA or any of the monoamine metabolites in CSF.

CONCLUSION

The results of this study suggest that increased KYNA formation is associated with an increased dopamine and serotonin turnover in male patients with schizophrenia.

Olanzapine and sulpiride: a preliminary study of combination/augmentation in patients with treatment-resistant schizophrenia

Coadministration of olanzapine, an atypical neuroleptic, with sulpiride, a selective D2 antagonist, is suggested as an efficient strategy for treating patients with resistant unremitting schizophrenia. The psychopharmacologic rationale that may account for the enhanced clinical efficacy of combining sulpiride with olanzapine and vice versa is the difference in affinity of the two drugs to brain receptors. Olanzapine affinity is related more to serotonin 5-HT2 than to dopamine-2, whereas sulpiride is considered a selective D2 blocker. The adjunction of a selective D2 antagonist to olanzapine may act as the olanzapine's augmentor by enhancing D2 blockage. This mode of treatment was introduced to six patients with chronic schizophrenia who showed noteworthy and rapid clinical improvement, supported by a decrease in their scores on the Positive and Negative Syndrome Scale and Brief Psychiatric Rating Scale. No bothersome side effects were noticed. This clinical approach is in accordance with the findings of previous reports assessing the efficacy of the combined treatment of clozapine and sulpiride. The grounds for this treatment regimen using olanzapine rather than clozapine are discussed, calling for further studies to affirm the hypothesis and clinical results.

Correlation between neuroleptic binding to sigma(1) and sigma(2) receptors and acute dystonic reactions

Acute dystonic reactions are motor side effects that occur soon after the initiation of neuroleptic treatment. Although earlier studies indicate that these abnormal movements can be induced in animals and humans via activation of sigma receptors, the relative contribution of the different sigma receptor subtypes is unknown. Since sigma(1) and sigma(2) receptor are differentially represented in motor regions of the brain, the affinities of 17 neuroleptics for these sigma receptor subtypes were determined using competition binding studies. The results revealed that most neuroleptics do not exhibit selectivity for either of the sigma receptor subtypes, as reflected by a significant correlation between the affinities of the neuroleptics for sigma(1) vs. sigma(2) receptors. Moreover, when the sigma binding affinities of the neuroleptics were correlated with the tendency of the drugs to produce acute dystonic reactions in humans, there was a significant correlation for both subtypes. Together with earlier studies in animals, the data suggest that neuroleptic-induced motor side effects can be mediated through both sigma(1) and sigma(2) receptors.

Sulpiride for schizophrenia

BACKGROUND

The antipsychotic drug sulpiride was formulated over 20 years ago and was marked as having a low incidence of adverse effects and an effect on the negative symptoms of schizophrenia. This relatively inexpensive antipsychotic drug has a similar neuropharmacological profile to several novel atypical drugs.

OBJECTIVES

To estimate the clinical efficacy and tolerability of sulpiride.

SEARCH STRATEGY

Electronic searches of Biological Abstracts (1982-1997), CINAHL (1982-1998), Cochrane Schizophrenia Group's Register (March 1998), Cochrane Library (Issue 1, 1998), EMBASE (1980-1998), MEDLINE (1966-1998), PsycLIT (1974-1997), SIGLE (1994-1998), and Sociofile (1974-1997) were supplemented by reference searching, contacting authors and the manufacturers of sulpiride.

SELECTION CRITERIA

All randomised or quasi-randomised clinical trials focusing on the use of different doses of sulpiride or comparing sulpiride to (i) placebo; (ii) typical antipsychotic drugs; or (iii) atypical antipsychotic drugs, for those with schizophrenia or serious mental illness were selected.

DATA COLLECTION AND ANALYSIS

Trials were reliably selected and quality rated. Data were independently extracted, by two reviewers (BGOS, MF), and analysed on an intention-to-treat basis. It was assumed that people who did not complete the follow up had no improvement. Authors of trials were contacted for additional and missing data. Relative risk (RR) and 95% confidence intervals (CI) of dichotomous data were calculated with the random effects model and weighted mean difference (WMD) was calculated for continuous data.

MAIN RESULTS

The review currently includes 18 studies (30 citations). Studies are generally small and of poor quality. Limited evidence suggests that there is little difference between sulpiride and other drugs although the incidence of side effects may be less for sulpiride. There are no clear findings relating to negative symptoms.

REVIEWER'S CONCLUSIONS

Sulpiride may be an effective antipsychotic drug but evidence is limited and data relating to claims for its value against negative symptoms is not trial-based.

Sulpiride augmentation in people with schizophrenia partially responsive to clozapine. A double-blind, placebo-controlled study

BACKGROUND

We hypothesised that a combined regimen of clozapine, a relatively weak D2-dopaminergic antagonist, and sulpiride, a selective D2 blocker, would demonstrate a greater antipsychotic efficacy by enhancing the D2 blockade of clozapine.

METHOD

Twenty-eight people with schizophrenia, previously unresponsive to typical antipsychotics and only partially responsive to current treatment with clozapine, received, double-blind, 600 mg/day sulpiride or placebo, in addition to an ongoing clozapine treatment. The clinical status was evaluated before, during, and at the end of 10 weeks of sulpiride addition using the Brief Psychiatric Rating Scale (BPRS), Scale for the Assessment of Positive Symptoms (SAPS), Scale for the Assessment of Negative Symptoms, and Hamilton Rating Scale for Depression.

RESULTS

The clozapine-sulpiride group exhibited substantially greater and significant improvements in positive and negative psychotic symptoms. About half of them, characterised by a younger age and lower baseline SAPS scores, had a mean reduction of 42.4 and 50.4% in their BPRS and SAPS scores, respectively.

CONCLUSIONS

A subgroup of patients with chronic schizophrenia may substantially benefit from sulpiride addition to clozapine.

A risk-benefit assessment of sulpiride in the treatment of schizophrenia

Sulpiride is a substituted benzamide with a selective action on receptors of the dopamine D2-like family, and clinical and pharmacological data suggest that it could be considered to be an atypical antipsychotic. Sulpiride penetrates the blood-brain barrier poorly because of its low lipid solubility. It is mainly excreted unchanged in the urine, and accumulation of the drug could occur in patients with renal dysfunction and possibly in elderly patients with declining glomerular filtration rate. At low dosages (50 to 150 mg/day), sulpiride produces a disinhibiting and antidepressant effect, which is probably related to its action on D2 presynaptic autoreceptors, thus facilitating dopaminergic neurotransmission. Data have confirmed the efficacy of sulpiride in patients with acute or chronic schizophrenia during both short and long term treatment, but long term, placebo-controlled trials are still lacking. It is still doubtful whether sulpiride is more effective than typical antipsychotics for the treatment of negative symptoms. Data from clinical studies are controversial; the majority of authors indicate that sulpiride produces a better recovery rate from negative than from positive symptoms at low doses, but it shows a similar efficacy either on negative and positive symptoms at higher doses. The safety profile of sulpiride is similar to that of typical antipsychotics, although the frequency of adverse effects seems to be globally lower. Extrapyramidal reactions appear generally to be mild. Autonomic effects occur less frequently with sulpiride than with typical antipsychotics, showing no clinically relevant influence on cardiovascular parameters and, on the whole, good tolerability in elderly patients. Sulpiride is known to induce prolactin elevation in both serum and CSF, which may be associated with impotence in men and diminished gonadal function in women; these effects appear to be dosage-dependent. Sulpiride can be considered to be an atypical antipsychotic, considering its action on negative, defective symptoms, its partial activity against positive symptoms, and its low incidence of extrapyramidal adverse effects. Sulpiride could find its specific therapeutic role in elderly patients with schizophrenia, as it shows a good margin of safety between therapeutic dosages and toxic concentrations.

Lack of apparent antipsychotic effect of the D1-dopamine receptor antagonist SCH39166 in acutely ill schizophrenic patients

SCH 39166 is the first selective D1 dopamine receptor antagonist developed for the treatment of schizophrenic patients. To examine potential antipsychotic effect, tolerability and safety, SCH 39166 was given orally to 17 acutely ill drug free schizophrenic patients (DSMIIIR) in an open 4-week study. Doses were escalated from 10 to 100 mg b.i.d. according to a fixed schedule over 17 days and remained at 100 mg b.i.d. for another 11 days. The drug was withdrawn prematurely in ten patients because of deterioration or refusal to take SCH 39166. In the nine patients participating for more than 2 weeks, none had an apparent reduction of BPRS or CGI scores. Side effects were agitation, akathisia and emesis in single patients. After withdrawal of SCH 39166 of the patients improved when treated with classical neuroleptics or clozapine. The result of the study does not support the prediction that selective D1 dopamine receptor antagonism will produce antipsychotic effects in schizophrenia.

Sulpiride: an antipsychotic with selective dopaminergic antagonist properties

OBJECTIVE

To review the pharmacology, pharmacokinetics, clinical investigations, and adverse effects of sulpiride as a treatment for schizophrenia.

DATA SOURCES

Information was selected from a MEDLINE search of English-language medical literature using "sulpiride" as the search term. Manual searches of pertinent journal article bibliographies also were performed.

STUDY SELECTION

Clinical investigations with a blind, controlled, randomized design and treatment durations of at least 6 weeks were preferred. Formal assessment of a patient's schizophrenia was required. One clinical investigation using a 4-week treatment duration and 1 open investigation were included for purposes of adverse reaction assessment.

DATA EXTRACTION

Clinical investigations were evaluated for design, sample size, diagnosis, duration, and outcome. Data from all investigations were selected by 1 author and reviewed by both authors.

DATA SYNTHESIS

Sulpiride is a substituted benzamide with selective dopaminergic blocking activity. Early pharmacology reports hypothesized that sulpiride was selective for dopamine (D)2 receptors only, but sulpiride also blocks D3 and D4 receptors. Sulpiride does not block D1, adrenergic, cholinergic, gamma-aminobutyric acid-ergic, histaminergic, or serotonergic receptors to an appreciable extent. The oral bioavailability of sulpiride is poor, with estimates approximating 35%. Sulpiride does not appear to have an extensive first-pass metabolism, nor is it extensively protein-bound. There have been no identified active metabolites, and elimination appears to depend primarily on the kidneys. Clinical studies support sulpiride as being equally effective as active controls in the acute treatment of patients with schizophrenia. Daily doses permitted in these clinical investigations ranged from 100 to 3200 mg. Further investigation is required to determine the usefulness of sulpiride as a chronic treatment of schizophrenia and its effectiveness in treating the negative symptoms of schizophrenia. Sulpiride may cause extrapyramidal effects, autonomic effects, tardive dyskinesia, and the neuroleptic malignant syndrome. The incidence of these adverse reactions has not been established.

CONCLUSIONS

Sulpiride is a safe and effective pharmacotherapeutic treatment for the acute management of schizophrenia. A unique pharmacology does not appear to provide sulpiride with a greater effectiveness than the standard antipsychotics, but may provide it with minor safety advantages.

Overcoming the neuroleptic-induced deficit syndrome: clinical observations with remoxipride

Remoxipride is a selective dopamine D2 antagonist with virtually no activity on other transmitter receptors. It antagonizes dopamine agonists within a wide dose range in animals when it does not cause sedation or akinesia. Clinical studies with remoxipride have demonstrated antipsychotic efficacy apparently equal to classical neuroleptics in short- and long-term treatment of schizophrenia. Remoxipride has a low extrapyramidal syndrome (EPS) profile, and it is generally well tolerated. In clinical practice remoxipride has been reported to differ from classical neuroleptics with regard to subjective side effects. On switching to remoxipride, patients report improvement in cognitive, conative, affective and emotional functions. In many cases the reports are supported by family members and/or caregivers. Although anecdotal, such reports are in line with the low EPS profile of remoxipride and its weak sedative properties. It may indicate that remoxipride does not elicit the neuroleptic-induced deficit syndrome, commonly experienced with classical neuroleptics, or that remoxipride improves the deficit syndrome (or primary negative symptoms) of schizophrenia. These and other hypotheses need to be confirmed by formal clinical studies.

L-sulpiride in young and elderly negative schizophrenics: clinical and pharmacokinetic variables

1. Clinical activity, tolerability and kinetic profile of L-sulpiride (200-300 mg/die p.o.) in relation to age, in 14 chronic schizophrenic in patients diagnosed according to DSM III-R, typed as negative forms, were studied. 2. The drug showed its efficacy in negative forms of schizophrenia, without any significant difference between negative and positive symptoms even if productive symptom scores were quite low already in pre-treatment condition. 3. No more side effects (anticholinergic and extrapyramidal) in elderly patients compared to young/adult ones were reported. 4. No significant differences between young/adult and elderly patients for the various pharmacokinetic parameters (t1/2, AUC, Cmax, Tmax, Vd and Cl), after acute and multiple dosing, were observed.

An open clinical and biochemical study of ritanserin in acute patients with schizophrenia

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 D2-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 D2-dopamine receptors. Thus, no indications of any D2-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 D2-dopamine blockade could be ruled out.

Comparison of the effect of substituted benzamides on midbrain dopamine neurones after treatment of rats for 21 days

We have tested five different substituted benzamides (nemonapride, D,L-sulpiride, remoxipride, raclopride and zacopride) for their potential to decrease the number of spontaneously active dopamine neurones in the rat midbrain after treatment for 21 days. Nemonapride, D,L-sulpiride, and remoxipride significantly reduced the number of spontaneously active dopamine neurones in the ventral tegmental area, indicating an antipsychotic potential, while raclopride and zacopride induced but minor effects. The number of active dopamine neurones in the substantia nigra pars compacta was reduced by nemonapride at higher doses which should indicate the propensity for developing extrapyramidal side-effects. In conclusion, several of the substituted benzamides showed an antipsychotic profile in this test model. In addition, some of the benzamides also showed a propensity for extrapyramidal side-effects and these results are in accordance with the profile reported from clinical trials. However, the results obtained with this model indicate that raclopride neither has antipsychotic potential nor induces extrapyramidal side-effects. The reason for this discrepancy is at present not known.

Neuroleptic treatment of negative symptoms in schizophrenic patients. Efficacy problems and methodological difficulties

The development and evaluation of the use of neuroleptics for negative symptoms of schizophrenia is becoming more and more of interest. However, severe methodological problems can lead to wrong conclusions in this field. The differentiation between primary and secondary negative symptoms and the interrelationship between negative symptoms, depression and akinesia have to be carefully considered. Many studies in this field are not conclusive because of such methodological pitfalls. After a careful review of published studies in this field no final conclusions can be drawn as to whether neuroleptics in general are effective in primary minus symptoms or whether certain neuroleptics are superior to others. Negative symptoms accompanying productive symptoms do improve with the neuroleptic treatment of the productive symptoms.

Treatment of schizophrenia: a clinical and preclinical evaluation of neuroleptic drugs

Forty years after the first clinical report on the effectiveness of chlorpromazine in psychiatric patients, neuroleptic drugs are still the most widely used drugs in the treatment of schizophrenia. Indeed, there are no other drugs which have proven to be as effective in the treatment of this severe psychiatric disorder. Yet, there are still many unresolved problems relating to neuroleptic drugs. The present review gives a comprehensive overview of our knowledge (and our lack of knowledge) with respect to the clinical and preclinical effects of neuroleptic drugs and tries to integrate this knowledge in order to identify the neuronal mechanisms underlying the therapeutic and side effects of neuroleptic drugs.

Lack of involvement of haloperidol-sensitive sigma binding sites in modulation of dopamine neuronal activity and induction of dystonias by antipsychotic drugs

The present studies evaluated previous suggestions that haloperidol-sensitive sigma binding sites are involved in the modulation of dopamine (DA) neuronal activity and in the induction of the dystonic effects of antipsychotic drugs. These issues were addressed by evaluating the effects of compounds that have differing affinities for sigma binding sites, on the firing activity of DA neurons in the substantia nigra in chloral hydrate-anesthetized rats and on the ability to induce extrapyramidal motor dysfunction in squirrel monkeys sensitized to the dystonic effects of haloperidol. The agents studied included haloperidol, DTG (1,3-di-o-tolylguanidine), (+)-pentazocine, (+)-SKF 10,047, BMY 14802, 8-OH-DPAT and sulpiride. There was no relationship between affinity for sigma binding sites and the ability to either alter DA neuronal activity or to induce extrapyramidal motor dysfunction.

Prevalence and severity of akathisia in patients on clozapine

The atypical antipsychotic clozapine is reported to have unique therapeutic effects and to produce minimal extrapyramidal side effects. However, in a blind survey, akathisia was observed to be similar in prevalence and severity in patients treated with clozapine and those receiving standard neuroleptic antipsychotic drugs. In addition, as with standard antipsychotic drugs, the presence of akathisia in patients receiving clozapine was associated with a worse overall clinical outcome. The results suggest that akathisia may be a common side effect of all antipsychotic drugs, that akathisia may be produced by a mechanism distinct from other locomotor effects of these medications, and that patients receiving clozapine, like patients receiving standard antipsychotic drugs, should be monitored for akathisia.

Mechanisms of action of atypical antipsychotic drugs. Implications for novel therapeutic strategies for schizophrenia

The mechanisms which contribute to the actions of atypical antipsychotic drugs, such as clozapine and the putative atypical agents remoxipride and raclopride, are reviewed. Examination of available preclinical and clinical data leads to two hypotheses concerning the mode of action of atypical antipsychotic drugs. The first hypothesis is that antagonism of the dopamine D2 receptor is both necessary and sufficient for the atypical profile, but that interaction with subtypes of the D2 receptor differentiates typical from atypical antipsychotic drugs. The second hypothesis has been previously advanced, and suggests that a relatively high ratio of serotonin 5-HT2:dopamine D2 receptor antagonism may subserve the atypical profile. It seems likely that the atypical antipsychotic drug profile may be achieved in more than one way.

Alterations in regional brain neurotensin concentrations produced by atypical antipsychotic drugs

Classical antipsychotic drugs, such as haloperidol, have been shown to increase the concentrations of neurotensin (NT) selectively in the nucleus accumbens and caudate nucleus of the rat. Several novel, putative antipsychotic drugs have also been found to produce increases in NT content in one or both of these brain regions. The present study sought to compare the effects of chronic treatment with three clinically efficacious atypical antipsychotic drugs, sulpiride, rimcazole and remoxipride, on regional brain NT concentrations to those of haloperidol. The concentrations of NT in five discrete brain regions were determined by a sensitive and specific radioimmunoassay. As previously reported, haloperidol increased NT concentrations in both the nucleus accumbens and caudate nucleus. Sulpiride and rimcazole produced significant increases in the concentration of NT in the caudate. NT concentrations were unaltered in any brain region by remoxipride at either of the doses tested. These data provide additional evidence for specific increases in regional brain NT concentrations produced by antipsychotic drugs.

Relationships between clinical effects and monoamine metabolites and amino acids in sulpiride-treated schizophrenic patients

Twenty-four acutely ill schizophrenic patients (DSM-III-R), 18-42 years old, were treated for 6 weeks with sulpiride. Sulpiride was administered in three different daily dosages (400, 800 or 1200 mg) according to a double dummy blind randomized administration schedule. The psychopathology of the patients was rated by the Comprehensive Psychopathological Rating Scale (CPRS) and the Nurse's Observation Scale for Inpatient Evaluation (NOSIE). The monoamine metabolites homovanillic acid (HVA), 5-hydroxy-indoleacetic acid (5-HIAA), 4-hydroxy-3-methoxy-phenylglycol (HMPG) and the amino acids tyrosine, tryptophan, glutamate and glutamine were measured in serum before and once a week during sulpiride treatment. There were no significant correlations between the CPRS or the NOSIE morbidity scores and the biochemical measures before drug treatment. HVA levels were not correlated to rating scores during treatment, but after 6 weeks HVA had decreased significantly in the patients with a good response but not in the patients with a poor response. A negative relationship between 5-HIAA levels and depressive and negative symptoms was found. Non-responders according to the subscale for depression had low 5-HIAA levels throughout the treatment. An increase of tryptophan was correlated to improvement in the early part of treatment. High levels of glutamate or glutamine were found in non-responders before treatment. During treatment an increase of the glutamate level was correlated to improvement. Low levels of glutamine were related to improvement according to global and NOSIE (total) rating scores. Peripheral biochemical measures may be a valuable tool in the study of pathophysiological mechanisms and treatment effects in patients with schizophrenia.

Monoamine metabolites and amino acids in serum from schizophrenic patients before and during sulpiride treatment

Twenty-four acutely ill schizophrenic patients (DSM-III-R), 18-42 years old, were treated for 6 weeks with sulpiride. Sulpiride was administered in three different daily dosages (starting with 400, 800 or 1200 mg) according to a double blind randomized administration schedule. The monoamine metabolites (MAM) homovanillic acid (HVA), 5-hydroxy-indoleacetic acid (5-HIAA), 4-hydroxy-3-methoxy-phenylglycol (HMPG) and the amino acids tyrosine, tryptophan, glutamate and glutamine were measured in serum before treatment and once a week during treatment. There were no significant differences between healthy controls and schizophrenic patients in serum levels of monoamine metabolites and amino acids before treatment. There was no dose-response effect of sulpiride on serum levels of the monoamine metabolites or the amino acids. The results are therefore based on the whole group of patients. During treatment the HMPG levels were reduced at all points in time. The serum level of HVA was significantly reduced after 6 weeks. The 5-HIAA and the amino acid levels were not changed during treatment. There were no significant correlations among the monoamine metabolites before treatment. During treatment, however, significant correlations were found among MAM and amino acids. Since the biochemical findings during the treatment were not related to the dose or the concentration of sulpiride the results may be related to secondary biochemical effects of sulpiride and/or to changes in the clinical state following treatment.

An open label trial of raclopride in acute schizophrenia. Confirmation of D2-dopamine receptor occupancy by PET

Raclopride, a highly selective D2-dopamine receptor antagonist, was administered in doses up to 4 mg b.i.d. to ten schizophrenic patients in an open label non-comparative study lasting 4 weeks. Safety, tolerability, potential antipsychotic effect, prolactin response and drug effect on plasma homovanillic acid were evaluated. Central D2-dopamine receptor occupancy was determined by positron emission tomography (PET). No major deviations were found in biochemical and physiological safety parameters. Raclopride was well tolerated. The mean BPRS score was reduced by 55% at endpoint. In the global evaluation seven patients were "very much" or "much" improved. Extrapyramidal side effects were recorded in four patients and disappeared after dose reduction or single doses of biperiden. An increase in plasma prolactin of short duration was observed in both sexes. A significant decrease of plasma HVA was obtained after 4 weeks of treatment. In two of the patients the central D2-dopamine receptors occupancy was measured using PET. The receptor occupancy was 68 and 72% which is the same as that found in patients treated with conventional neuroleptics.

Skin conductance nonresponding and nonhabituation in schizophrenic patients

Bilateral skin conductance (SC) and heart rate (HR) were measured for 18 RDC diagnosed schizophrenic patients during rest and during presentation of identical tones. Computed tomography scans were evaluated. All but two patients were on neuroleptic medication. Six patients were nonresponders, seven habituated to the tones and five were nonhabituators. Nonresponders had lower SC level, fewer SC spontaneous fluctuations and higher HR level than the other subgroups. On neuropsychological tests the performance of the habituator group was closest to that of healthy subjects. Nonresponders did not differ in clinical symptoms, anamnestic data or in the prevalence of psychiatric morbidity in their families. Seventeen percent of the nonresponders had poor premorbidity adjustment vs 80% of the nonhabituators. Nonhabituators had higher ranks in the following symptoms: Presence of commenting voices, and inability to feel. They also tended to have wider third ventricles than the other two subgroups. The results support earlier findings in our laboratory suggesting nonhabituators as an important subgroup among schizophrenic patients.

Dexamethasone suppression test in schizophrenic patients before and during neuroleptic treatment

The dexamethasone suppression test (DST) was performed in 21 drug-free schizophrenic patients. The patients satisfied DSM-III and Research Diagnostic Criteria for schizophrenia and were in an acute phase of the disease. In 15 of the patients the DST was repeated after about 5 weeks of treatment with neuroleptics. DST compliance was checked by analysis of dexamethasone concentrations in plasma. In the acute phase 71% (at 04 p.m.) of the patients were nonsuppressors. After neuroleptic treatment the frequency of abnormal responders had decreased to 20%. The decrease in nonsuppressors was not due to alteration of the dexamethasone concentration between the two test occasions. Prolactin levels were markedly increased at the second test occasion compared with the first. There were no significant relationships between cortisol levels, cortisol suppression and prolactin levels. The high frequency of nonsuppressors among schizophrenic patients in the acute phase of the disease indicates that acute stress may be a confounding factor in the outcome of DST.

Sulpiride and haloperidol in schizophrenia: a double-blind cross-over study of therapeutic effect, side effects and plasma concentrations

In a double-blind cross-over trial, 20 chronic schizophrenic patients were treated with sulpiride and haloperidol in two 12-week periods. The final median dose of sulpiride was 2000 mg/day (range 800-3200) and of haloperidol 12 mg/day (range 6-24). Sulpiride had an antipsychotic effect and therapeutic profile not significantly different from that of haloperidol. In spite of the high doses of sulpiride, extrapyramidal side-effects were seen less frequently during the first four weeks of the sulpiride period than during the corresponding haloperidol period (P less than 0.05), whereas autonomic side-effects were equally rare for both drugs. A positive correlation was found between daily dose and plasma concentration of both sulpiride (P less than 0.001) and haloperidol (P less than 0.05), but no correlation could be established between clinical effects and plasma levels of either neuroleptic.

Gas chromatographic-mass spectrometric determination of myo-inositol in human cerebrospinal fluid

The concentration of free myo-inositol in CSF was determined with a gas chromatographic-mass spectrometric method using deuterated myo-inositol as an internal standard after conversion to the hexa-O-acetyl derivative with acetic anhydride and pyridine. Twenty microliters of CSF is sufficient for the analysis which has a coefficient of variation of 9%. Identical analytical results were obtained on two different mass numbers. Schizophrenic patients were compared with healthy control persons. In addition, patients with rheumatoid arthritis or with neurological illnesses were studied. No consistent differences related to the illness could be found. The mean concentration of myo-inositol was about 25 micrograms/ml. Treatment of schizophrenic patients with chlorpromazine or sulpiride had no significant effect on the concentration of myo-inositol in CSF.

Smooth pursuit eye tracking, neuropsychological test performance, and computed tomography in schizophrenia

Smooth pursuit eye movements (SPEM) were measured in 18 patients who met Research Diagnostic Criteria for schizophrenia. Some degree of SPEM impairment was present in most patients. Deviant eye tracking was not related to ratings of severity of illness, but was related to recurrent episodes of hospitalization, antipsychotic medication, and lower ratings in anxiety and delusions. Worse SPEM tended to be associated with larger lateral ventricles as assessed on computed tomography. Three patients with reversed occipital asymmetry had more deviant eye tracking than the remaining patients. Eye movement impairment was related to worse performance in Finger Tapping and in the Trail-Making Test, and to fewer perceived alternations of a Necker cube, suggesting that frontoparietal disturbances are related to poor pursuit eye tracking in schizophrenia.

Effects of sulpiride and chlorpromazine on autistic and positive psychotic symptoms in schizophrenic patients--relationship to drug concentrations

Schizophrenic patients were treated with fixed doses of sulpiride (800 mg/day) or chlorpromazine (CPZ) (400 mg/day) during a period of 8 weeks using a double-blind design. There were 25 patients in each group and all of them fulfilled the Research Diagnostic Criteria (RDC) for schizophrenia. Autistic and psychotic symptoms were rated with subscales developed from the Comprehensive Psychopathological Rating Scale (CPRS). Autistic symptoms were also rated with a subscale of the Nurse's Observation Scale for Inpatient Evaluation (NOSIE). Sulpiride was superior to CPZ in reducing the autistic symptoms. Patients with low concentrations of sulpiride in serum had a better recovery rate from autistic symptoms than those with high concentrations. Both drugs reduced positive psychotic symptoms to the same degree.

Pharmacokinetics of oral moclobemide in healthy human subjects and effects on MAO-activity in platelets and excretion of urine monoamine metabolites

The plasma concentrations of the MAO-inhibitor moclobemide (Ro 11-1163) were determined in six healthy male subjects after oral (tablets) administration. Effects on MAO activity in platelets and excretion of monoamine metabolites in urine were investigated. The design of the study was a double-blind cross-over study with single oral doses of placebo, 50, 100 and 200 mg of moclobemide. The elimination profile of the drug showed that the half life of the unchanged drug ranged between 1 and 2 h except in one subject with a half-life of about 4 h. The mean bioavailability calculated using flow model concepts was F = 0.43 after 50 mg, F = 0.47 after 100 mg and F = 0.59 after 200 mg. The outlier with a t 1/2 of 4 h was found to have a bioavailability of more than 0.80 after all 3 doses. The slightly increasing bioavailability with higher doses was interpreted as evidence of saturable hepatic first-pass elimination of the drug. MAO activity in platelets was measured before and 2, 6 and 24 h after drug administration. No inhibition of platelet MAO was obtained at any point in time or dose level, as to be expected since moclobemide preferentially inhibits MAO A. Urine excretion of the monoamine metabolites homovanillic acid (HVA), dihydroxyphenylacetic acid (DOP-AC), 3-methoxy-4-hydroxy-phenylglycol (MOPEG) and 5-hydroxyindoleacetic acid (5-HIAA) was followed during 48 h after placebo, 50 and 200 mg of moclobemide. Time but not dose contributed significantly to the variability in excretion of the monoamine metabolites.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of sulpiride and chlorpromazine on depressive symptoms in schizophrenic patients--relationship to drug concentrations

Schizophrenic patients were treated with fixed doses of sulpiride (800 mg/day) or chlorpromazine (CPZ) (400 mg/day) over a period of 8 weeks using a double-blind design. There were 25 patients in each group and all the patients were in an acute phase of their disease. They all fulfilled the Research Diagnostic Criteria (RDC) for schizophrenia. Depressive symptoms as rated according to the Comprehensive Psychopathological Rating Scale (CPRS) were present in the patients before treatment was started. The depressive and psychotic symptoms in both groups decreased in parallel during the whole period of treatment. Patients in the sulpiride group recovered more quickly from depressive symptoms than patients in the CPZ group. It was also found that patients with low concentrations of sulpiride or CPZ in serum recovered more completely from depressive symptoms and had fewer extrapyramidal side effects than patients with high drug concentrations.