Role of NMDA receptor subtypes in the induction of catalepsy and increase in Fos protein expression after administration of haloperidol

The increase of Fos expression in the striatum induced by haloperidol, an antagonist of the dopamine D2 receptor, might be related to the activation of glutamatergic neurotransmission, especially that of N-methyl-D-aspartate (NMDA) receptors. In this study, using behavioral and immunohistochemical techniques, we examined the effects of a noncompetitive NMDA antagonist, (+)-MK-801, and an NMDA receptor NR2B subunit antagonist, ifenprodil, on catalepsy, an extrapyramidal symptom; in this context, we also considered the expression of Fos protein in the forebrain after the administration of haloperidol. Catalepsy in mice, induced by the administration of haloperidol (1 mg/kg), was inhibited by pretreatment with (+)-MK-801 (0.2 mg/kg) or ifenprodil (10 mg/kg). Furthermore, pretreatment with (+)-MK-801 (0.2 mg/kg) significantly attenuated the induction of Fos-immunoreactive (IR) cells in the dorsomedial, dorsolateral, and ventrolateral striatum, but not in the shell region of the nucleus accumbens after the administration of haloperidol, whereas pretreatment with ifenprodil (10 mg/kg) significantly attenuated the induction of Fos-IR cells in all of these areas. It is known that ifenprodil binds sigma receptors and alpha-1 adrenergic receptors with high affinity. Pretreatment with the sigma receptor antagonist BD-1407 (3 mg/kg) or the alpha-1 adrenergic receptor antagonist prazosin (3 mg/kg) affected neither catalepsy nor the expression of Fos-IR cells after the administration of haloperidol. However, pretreatment with CP-101,606 (1 mg/kg), a selective antagonist for the NR2B subunit of the NMDA receptor, significantly attenuated catalepsy and the expression of Fos-IR cells in the forebrain after the administration of haloperidol. These results suggest that the NMDA receptor antagonists attenuated the induction of catalepsy and Fos-IR cells in forebrain after the administration of haloperidol. It was also suggested that haloperidol-induced expression of Fos-IR cells in the shell region of the nucleus accumbens might be differentially regulated by NMDA receptor subunits. Therefore, it appears that selective antagonists for the NR2B subunit of the NMDA receptor (e.g., CP-101,606) might be useful drugs for the treatment of extrapyramidal side effects (EPS) associated with the chronic use of typical antipsychotics such as haloperidol.

Prolactin levels in antipsychotic treatment of patients with schizophrenia carrying the DRD2*A1 allele

BACKGROUND

Hyperprolactinaemia induced by D(2) dopamine receptor antagonist antipsychotic medication can result in significant health problems.

AIMS

To examine the role of DRD2 polymorphism on prolactin levels in patients treated with antipsychotic medication.

METHOD

Antipsychotic drugs with different degrees of D(2) receptor binding were given to 144 patients with schizophrenia. Serum prolactin levels were obtained and Taq1A DRD2 alleles were determined.

RESULTS

Prolactin levels increased across medication groups reflecting increasingly tight D(2) receptor binding (clozapine, olanzapine, typical antipsychotics and risperidone). In the combined medication group, patients with the DRD2(*)A1allele had 40% higher prolactin levels than patients without this allele. In patients treated with clozapine (the loosest D(2) receptor binding agent), patients with the DRD2(*)A1allele had prolactin levels twice those of patients without this allele.

CONCLUSIONS

Patients with the DRD2A1 allele receiving antipsychotic medications had higher prolactin levels and were overrepresented among those with hyperprolactinaemia, suggesting greater functional D(2) receptor binding in this group.

Haloperidol Impairs Learning and Error-related Negativity in Humans

Humans are able to monitor their actions for behavioral conflicts and performance errors. Growing evidence suggests that the error-related negativity (ERN) of the event-related cortical brain potential (ERP) may index the functioning of this response monitoring system and that the ERN may depend on dopaminergic mechanisms. We examined the role of dopamine in ERN and behavioral indices of learning by administering either 3 mg of the dopamine antagonist (DA) haloperidol (n = 17); 25 mg of diphenhydramine (n = 16), which has a similar CNS profile but without DA properties; or placebo (n = 18) in a randomized, double-blind manner to healthy volunteers. Three hours after drug administration, participants performed a go/no-go Continuous Performance Task, the Eriksen Flanker Task, and a learning-dependent Time Estimation Task. Haloperidol significantly attenuated ERN amplitudes recorded during the flanker task, impaired learning of time intervals, and tended to cause more errors of commission, compared to placebo, which did not significantly differ from diphenhydramine. Drugs had no significant effects on the stimulus-locked P1 and N2 ERPs or on behavioral response latencies, but tended to affect post-error reaction time (RT) latencies in opposite ways (haloperidol decreased and diphenhydramine increased RTs). These findings support the hypothesis that the DA system is involved in learning and the generation of the ERN.

The utility of intramuscular ziprasidone in the management of acute psychotic agitation

Many psychiatric illnesses, including chronic schizophrenia, bipolar disorder, and dementia, are characterized by episodes of acute agitation, making administration of oral agents difficult or impossible. Ziprasidone, the first atypical antipsychotic available in both intramuscular (IM) and oral formulations, has demonstrated significant control of acute agitation within 15 minutes, as seen in two 24-hour studies in patients with schizophrenia. Improvement was maintained for > or = 4 hours, and a low incidence of extrapyramidal symptoms, akathisia, and dystonia as well as no excessive sedation were observed Also, two 7-day studies (n = 132 and n = 306) and one 6-week study (n = 567) of sequential IM/oral ziprasidone versus IM/oral haloperidol in patients with psychotic disorders found IM ziprasidone more effective than IM haloperidol within 3 days of IM treatment; both drugs produced further comparable improvements in efficacy parameters after transition to oral therapy. IM ziprasidone was associated with a lower incidence of movement disorders than was haloperidol in all of these studies. Overall, discontinuations were similar for IM ziprasidone and haloperidol in the comparative trials, including the sequential IM/oral studies. However, in the 6-week sequential IM/oral trial, the rate of discontinuation due to adverse events was twice as high among haloperidol vs ziprasidone patients. This report focuses on the pharmacology, clinical efficacy, and tolerability of IM ziprasidone, and provides an overview of the utility of other commonly used antipsychotics in the management of acute psychotic agitation.

Effects of long-term prolactin-raising antipsychotic medication on bone mineral density in patients with schizophrenia

BACKGROUND

High rates of osteoporosis in schizophrenia may result from the prolactin-raising effects of some antipsychotic medication. Aims To examine bone mineral density in relation to relevant endocrine variables in patients with schizophrenia taking prolactin-raising antipsychotics.

METHOD

Fifty-five patients who had been receiving prolactin-raising antipsychotic medication for >10 years underwent dual-energy X-ray absorptiometry of their lumbar and hip bones. Among the endocrine variables assessed were plasma prolactin and sex hormones.

RESULTS

Age-related reduced bone mineral density measures were found in 17 (57%) of the male and 8 (32%) of the female patients. Higher doses of the female patients. Higher doses of medication were associated with increased rates of both hyperprolactinaemia and bone mineral density loss. Bone loss for the whole group was correlated with medication dose, and for men was inversely correlated with testosterone values.

CONCLUSIONS

These results suggest that patients with schizophrenia on long-term prolactin-raising antipsychotic medication are at high risk of developing reduced bone mineral density as a consequence of hyperprolactinaemia-induced hypogonadism.

Agonist-like or antagonist-like treatment for cocaine dependence with methadone for heroin dependence: two double-blind randomized clinical trials

Concurrent abuse of cocaine and heroin is a common problem. Methadone is effective for opioid dependence. The question arises as to whether combining agonist-like or antagonist-like medication for cocaine with methadone for opioid dependence might be efficacious. Two parallel studies were conducted. One examined sustained release d-amphetamine and the other risperidone for cocaine dependence, each in combination with methadone. In total, 240 subjects (120/study) were recruited, who were both cocaine and heroin dependent and not currently receiving medication. All provided consent. Both studies were carried out for 26 weeks, randomized, double-blind and placebo controlled. Study I compared sustained release d-amphetamine (escalating 15-30 or 30-60 mg) and placebo. Study II examined risperidone (2 or 4 mg) and placebo. All subjects underwent methadone induction and were stabilized at 1.1 mg/kg. Subjects attended clinic twice/week, provided urine samples, obtained medication take-home doses for intervening days, and completed self-report measures. Each had one behavioral therapy session/week. In Study I, reduction in cocaine use was significant for the 30/60 mg dose compared to the 15/30 mg and placebo. Opioid use was reduced in all groups with a trend toward greater reduction in the 30/60 mg d-amphetamine group. In Study II, methadone reduced illicit opioid use but cocaine use did not change in the risperidone or placebo groups. There were no adverse medication interactions in either study. The results provide support for the agonist-like (d-amphetamine) model in cocaine dependence treatment but not for antagonist-like (risperidone) treatment. They coincide with our previous reports of amphetamine or risperidone administered singly in cocaine-dependent individuals.

Diphenhydramine in the treatment of akathisia induced by prochlorperazine

Dopamine D(2) antagonists are known to induce akathisia, the emergency management of which remains undetermined. We sought to evaluate the effectiveness of diphenhydramine in the treatment of akathisia induced by 10 mg intravenous prochlorperazine. This prospective, open-label, uncontrolled study evaluated a cohort of akathisic adult Emergency Department patients who were participating in a series of three studies of acute akathisia at an academic medical center. Each subject received intravenous diphenhydramine, with akathisia measurements (graded from 0-17 points) performed just before and 30 min after infusion. Mean scores were calculated using descriptive statistical analyses. The effect of treatment was evaluated using the paired t-test. For the 87 akathisic patients, the mean score before treatment was 9.8 +/- 3.6, and after treatment was 1.2 +/- 2.6, a mean reduction of 8.5 +/- 3.8 (95% confidence interval [CI], 7.8 to 9.4; p < 0.0001). In conclusion, intravenous diphenhydramine rapidly reduces signs and symptoms of acute akathisia induced by prochlorperazine.

Psychopharmaka und Herzrhythmusstörungen

Psychopharmaka verschiedener Stoffklassen werden seit vier Jahrzehnten mit Herzrhythmusstörungen assoziiert. Bis in die frühen 90er Jahre beschränkte sich das Problem scheinbar auf Intoxikationen oder auf Patienten mit vorbestehenden Herzerkrankungen. In den letzten zehn Jahren hat sich jedoch gezeigt, dass auch normal dosierte, nicht-kardiale Medikamente bei gesunden Personen unter bestimmten Umständen lebensbedrohliche Rhythmusstörungen auslösen können. Die Gemeinsamkeit dieser Medikamente ist die Eigenschaft, das QT-Intervall zu verlängern. Unter den Neuroleptika ist das niedrig potente Phenothiazin Thioridazin (Melleril) dafür am besten belegt. Auch von hochpotenten Neuroleptika existieren einige Berichte über proarrhythmische Eigenschaften. Während eine QT-Verlängerung auch bei neuen, atypischen Neuroleptika beschrieben wurde, sind Torsade de pointes und plötzliche Todesfälle bisher nur in Einzelfällen beschrieben worden. Medikamente mit Klasse I antiarrhythmischer Wirkung sind nach Myokardinfarkt potenziell gefährlich, und damit sollten trizyklische Antidepressiva mit ihrer Klasse I Wirkung bei ischämischer Herzkrankheit vermieden werden. Selektive Serotonin Re-uptake Inhibitoren können aufgrund bisher verfügbarer Daten bei dieser Patientengruppe als sicher bezeichnet werden. Bei Patienten mit vorbestehender QT-Verlängerung oder bei Patienten nach Torsade de pointes unter anderer Medikation sind Substanzen mit QT-verlängernder Wirkung zu vermeiden. Wechselwirkungen mit andern Medikamenten können sehr bedeutsam sein. Lithium ist bekannt für seine Sinusknoten- und Reizleitungsstörungen.

Drug-induced myoclonus: frequency, mechanisms and management

Myoclonus is a sudden, abrupt, brief, 'shock-like' involuntary movement caused by muscular contractions ('positive myoclonus') or a sudden brief lapse of muscle contraction in active postural muscles ('negative myoclonus' or 'asterixis'). Various disorders can cause myoclonus including neurodegenerative and systemic metabolic disorders and CNS infections. In addition, myoclonus has been described as an adverse effect of some drugs. Level II evidence is available to indicate that levodopa, cyclic antidepressants and bismuth salts can cause myoclonus, while there is less robust evidence to associate numerous other drugs with the induction of myoclonus. The pharmacological mechanisms responsible for this adverse effect are not well established, although increased serotonergic transmission may be involved in the induction of myoclonus by several drugs. Drug-induced myoclonus usually resolves after withdrawal of the offending drug, but in some cases specific treatments are needed.

Amisulpride a selective dopamine antagonist and atypical antipsychotic: results of a meta-analysis of randomized controlled trials

The pharmacological profiles of the atypical antipsychotics, clozapine, olanzapine, quetiapine and risperidone, all show a combined serotonin (5-HT2) and dopamine type-2 (D2) receptor antagonism. Amisulpride, a highly selective dopamine D2/D3 receptor antagonist that binds preferentially to receptors in the mesolimbic system, is also an 'atypical' antipsychotic despite having a different receptor-affinity profile. A meta-analysis of 18 clinical trials was undertaken to compare the efficacy and safety of amisulpride with conventional antipsychotics. The improvement in mental state was assessed using the Brief Psychiatric Rating Scale (BPRS) or the Scale for the Assessment of Negative Symptoms (SANS). In a pooled analysis of 10 studies of acutely ill patients, amisulpride was significantly more effective than conventional neuroleptics with regard to improvement of global symptoms. Amisulpride is, to date, the only atypical antipsychotic for which several studies on patients suffering predominantly from negative symptoms have been published. In four such studies, amisulpride was significantly superior to placebo. Three small studies with conventional neuroleptics as a comparator showed only a trend in favour of amisulpride in this regard. Amisulpride was associated with fewer extrapyramidal side-effects and fewer drop-outs due to adverse events than conventional neuroleptics. These results clearly show that amisulpride is an 'atypical' antipsychotic, and they cast some doubt on the notion that combined 5-HT2-D2 antagonism is the only reason for the high efficacy against negative symptoms and fewer extrapyramidal side-effects.

Adverse effects of risperidone and haloperidol treatment in schizophrenia

PURPOSE

Side effects of pharmacological treatment in schizophrenia continue to be a major issue in spite of the development of new antipsychotics. The aim of this study is to explore the adverse effects of conventional and atypical antipsychotic drugs and their associated factors.

METHODS

Over 3 months, 41 patients with schizophrenia were randomized to treatment with risperidone 1-12 mg (n=21) or haloperidol 2-20 mg (n=20) daily. Efficacy was assessed by improvement of psychotic symptoms, measured on the Positive and Negative Syndrome Scale (PANSS). The safety and tolerability were assessed with the Extrapyramidal Symptom Rating Scale, the UKU Side-Effect Rating Scale and clinical laboratory assessments.

RESULTS

Each treatment reduced psychotic symptoms. PANSS total scores, positive scores, and general psychopathology scores declined as trial went on without significant differences between the two groups. While PANSS negative scores improved better in the risperidone group than in the haloperidol group. The tolerability of antipsychotics was statistical significantly better in the risperidone than in the haloperidol-treated patients. The most frequent adverse effects for both groups were tremor and rigidity. Antipsychotics, their doses, and hyperprolactinemia predict short-term extrapyramidal side effects. Serum prolactin levels could predict parkinsonism and dyskinesia severity. However, dyskinesia was best predicted by the doses of neuroleptics. The predictive factor of dystonia was the antipsychotic drug itself. After adjusting drug doses and concomitant medications, side effects could be markedly improved.

CONCLUSIONS

This study suggested that risperidone was superior to haloperidol in improving negative symptoms and better tolerated during the 12 weeks' treatment of schizophrenia. Serum prolactin levels could predict the severity of parkinsonism and dyskinesia.

How do we choose between atypical antipsychotics? The advantages of amisulpride

Clinician choice of an atypical antipsychotic may depend on a number of factors such as perceived efficacy, tolerability and cost. It is also important that the choice of treatment takes into consideration the previous response to treatment, experience of side-effects and personal clinical characteristics. The receptor-affinity profiles of the atypical antipsychotics differ; with the exception of amisulpride, a selective D2/D3 antagonist, all the atypical antipsychotics exhibit a greater affinity for the serotonin-2A receptors than dopamine receptors. However, there is no evidence that the variation in receptor affinities is relevant to efficacy. Indeed, the crucial factor may be fast dissociation from low affinity for the D2 receptor. Tolerability also varies between the atypical antipsychotics and the side-effect profile may be related to the receptor-affinity profile of the individual drugs. Extrapyramidal side-effects are generally less of a problem with most atypical drugs than with conventional drugs, but weight gain, loss of glycaemic control, sedation and hyperprolactinaemia remain problematic in some patients. Amisulpride is effective for the treatment of both positive and negative symptoms, and is well tolerated with regard to weight gain, glucose tolerance and sedation. In two clinical trials, the AMIRIS and SOLIANOL studies, amisulpride demonstrated clear advantages over some other atypical antipsychotics with respect to negative symptoms, depressive symptoms and weight gain.

Droperidol vs. prochlorperazine for the treatment of acute headache

To determine if droperidol i.v. is as effective as prochlorperazine i.v. in the emergency department (ED) treatment of uncomplicated headache, a randomized, controlled, blinded study was conducted in the Emergency Departments of two urban teaching hospitals. Patients >or= 18 years old with crescendo-onset headache were eligible for inclusion. Ninety-six patients (48 in each group) were randomized to receive droperidol 2.5 mg i.v. or prochlorperazine 10 mg i.v. Baseline characteristics were similar between the two study groups. For the main study outcome, 83.3% in the droperidol group and 72.3% in the prochlorperazine group reported 50% pain reduction at 30 min (p <.01; one-sided test of equivalence). The mean decrease in headache intensity was 79.1% (SD 28.5%) in the droperidol group and 72.1% (SD 28.0%) in the prochlorperazine group (p =.23). It is concluded that droperidol i.v. provided a similar reduction of headache as achieved with prochlorperazine i.v. with a similar incidence of akathisia.

Memantine attenuates the increase in striatal preproenkephalin mRNA expression and development of haloperidol-induced persistent oral dyskinesias in rats

Tardive dyskinesia (TD) is a serious motor side effect of long-term neuroleptic treatment that may persist after drug withdrawal. Alterations in striatal enkephalinergic neurons due to excessive glutamatergic activity is a possible pathogenetic mechanism. We studied the effect of the NMDA antagonist memantine in a rat model of TD, in which vacuous chewing movements (VCM) were induced by 20 weeks of haloperidol administration. The striatal density of preproenkephalin mRNA was measured and the number of neurons estimated. Haloperidol induced persistent VCM that was associated with increased striatal expression of preproenkephalin mRNA. Memantine inhibited the development of haloperidol-induced persistent VCM and attenuated the increase in preproenkephalin mRNA expression. This suggests that glutamate-mediated up-regulation of striatal enkephalin plays a role in the development of haloperidol-induced persistent oral dyskinesias.

Are dopamine antagonists a risk factor for breast cancer? An answer from Parkinson's disease

Women undergoing chemotherapy for breast cancer are often administered dopamine antagonist adjuvant medications that may increase levels of prolactin potentially increasing the risk of cancer. Using nationwide computerized registers of death data for the years 1991 through 1996 we examined 12,430,473 deaths of persons over 40 years of age and extracted 144,364 cases with Parkinson's disease (PD), a dopamine deficient population. Patients with PD had lower rates of breast and other types of malignancies, even in the presence of depression and suicide.

[Correction of acute psychotic states in schizophrenia by rispolept solution per os]

To stop acute psychotic states during the first episode or relapses of schizophrenia, 37 patients were treated with rispolept solution per os during 2 weeks. A procedure of a fast transition to optimal daily doses of the drug after 1 day of treatment (searching period) with a following stabilization of mean daily doses (5.02-5.7 mg) at the stage of 14 day treatment course was used. Positive therapeutic effect by PANSS total score reduction, along with minor side-effects, were found in 91.9% patients. Stopping effect of rispolept on acute psychotic states, emerging from day 1 of the treatment, and general antipsychotic and therapeutic action, beginning from day 2-3 and increasing to day 14, were stated out. Efficacy of the drug in syndromes differing by psychopathological structure is emphasized.

Mouvements anormaux d’origine médicamenteuse : les syndromes tardifs

Persistent drug-induced movement disorders (tardive syndromes) remain an important clinical problem and consist of a variety of involuntary movements appearing in a patient exposed to a dopamine-blocking agent. The current state of knowledge on this topic is summarised in this article. Clinical aspects (tardive dyskinesia, tardive dystonia and other forms), prevalence, risk factors, prevention and management are discussed.

[Mechanism of nootropic digam action in hypofunction of brain dopaminergic system]

Using microchemical methods for detection of dopamine (DA), noradrenaline (NA), serotonin (S) and its metabolite--5'-hydroxyindolilacetic acid (5'-HIAA) as well as the activity of neuromediator-utilising enzymes--MAO A and B and enzymes of acetylcholine metabolism--cholinacetyltranspherase (ChAT) and acetylcholinesterase (AChE), we revealed that synthetic GABA-derivative compound diagram (250 mg/kg during 10 days) normalized functioning of dopaminergic and acetylcholinergic systems in sensormotor cortex and caudate nucleus of Wistar rats with haloperidol-induced (0.5 mg/kg during 30 days) bradykinesia. Measured by quantitative interpherometric method, a specific response of functionally different sensomotor cortex (layers III and V) neurons and caudate nucleus by such characteristics as cytoplasm and nuclei sizes, protein content and concentration was found. Control for rat's behavior in open field revealed that diagram restored emotional activity disturbed by haloperidol injections and improved the indices of the animals searching activity.

[An open trial of risperidone in autistic children]

Clinical effects of risperidone were evaluated in 9 young autistic children under informed consent of their parents. The patients were evaluated by the Children's Behavioral Checklist and Rutter's Autistic Behavioral Rating Scale. After the administration, two subjects (playing and adaptation to change) of the Children's Behavioral Checklist and four (anomalous autistic behavior, destructive behavior, developmental problem and activity level) of the Rutter's Autistic Behavioral Rating Scale were improved significantly. There were no serious side effects such as extrapyramidal symptoms except minor adverse effects including sedation, depression, increased appetite and constipation. Risperidone might be effective for serious behavioral disturbances in young autistic children.

Immune activation during pregnancy in rats leads to a postpubertal emergence of disrupted latent inhibition, dopaminergic hyperfunction, and altered limbic morphology in the offspring: a novel neurodevelopmental model of schizophrenia

Prenatal exposure to infection is associated with increased liability to schizophrenia, and it is believed that such an association is mediated by the maternal immune response, in particular, the proinflammatory cytokines released by the maternal immune system, which may disrupt fetal brain development. Impaired capacity to ignore irrelevant stimuli is one of the central deficits in schizophrenia, and is manifested, among others, in loss of latent inhibition (LI), a phenomenon whereby repeated inconsequential pre-exposure to a stimulus impairs its subsequent capacity to signal significant consequences. We tested the effects of prenatal immune activation induced by peripheral administration of the synthetic cytokine releaser polyriboinosinic-polyribocytidilic acid (poly I : C) to pregnant dams, on LI in juvenile and adult offspring. Consistent with the characteristic maturational delay of schizophrenia, prenatal immune activation did not affect LI in the juvenile offspring, but led to LI disruption in adulthood. Both haloperidol (0.1 mg/kg) and clozapine (5 mg/kg) reinstated LI in the adult offspring. In addition, prenatal immune activation led to a postpubertal emergence of increased sensitivity to the locomotor-stimulating effects of amphetamine and increased in vitro striatal dopamine release, as well as to morphological alterations in the hippocampus and the entorhinal cortex in the adult offspring, consistent with the well-documented mesolimbic dopaminergic and temporolimbic pathology in schizophrenia. These results suggest that prenatal poly I : C administration may provide a neurodevelopmental model of schizophrenia that reproduces a putative inducing factor; mimics the temporal course as well as some central abnormalities of the disorder; and predicts responsiveness to antipsychotic drugs. Neuropsychopharmacology (2003) 28, 1778-1789. advance online publication, 16 July 2003; doi:10.1038/sj.npp.1300248

Establishing a Comprehensive Questionnaire for Detecting Drug-induced Extrapyramidal Symptoms

OBJECTIVE

Drug-induced extrapyramidal symptoms (DIEPS) often substantially compromise quality of life (QOL) of patients receiving drugs with central antidopaminergic activities. A lack of comprehensive screening method based upon patients' subjective symptoms for detecting DIEPS appears to have prevented pharmacists from delivering satisfactory pharmaceutical care for these patients. Thus, we have attempted to develop a comprehensive questionnaire for screening patients having higher risks of developing DIEPS.

METHODS

One hundred fourteen outpatients taking gastroprokinetic drugs (itopride, cisapride, trimebutine, domperidone and metoclopramide) at least 2 weeks participated in the study. One patient with familial Parkinson disease served as a positive reference. They undertook a questionnaire consisting of 9 comprehensive questions written in non-technical words that were aimed to detect typical symptoms of Parkinsonism including akathisia and dyskinesia. Each symptom was scored in a semiquantitative scale [i.e., from 1 (not at all) to 5 (very much)] by the patients.

RESULTS

Of the 108 subjects who successfully completed the questionnaires, 43 gave scores 2 or greater indicating the presence of DIEPS. However, no statistically significant correlations were observed between the scores of any possible pairs of the questionnaire items. Five subjects had a mean questionnaire score of equal to or greater than 1.6, and the patient with familiar Parkinsonism had the highest mean score of 1.9.

CONCLUSION

The questionnaire presented herein detected 4 patients with suspected DIEPS. Further studies should be warranted to assess whether it would be useful for pharmacists as a screening tool for DIEPS in patients having higher risks of DIEPS.

Role of aging and striatal nitric oxide synthase activity in an animal model of tardive dyskinesia

The risk of tardive dyskinesia (TD) increases with advancing age. Haloperidol increases striatal oxidative stress and inhibits nitric oxide (NO) synthase (NOS) in vitro. Biological aging is associated with increased oxidative stress and reduced brain NOS activity. This paper has explored aging and striatal NOS activity ex vivo as co-morbid factors in an animal model of TD. Young adult, mature adult and aged rats were treated with water or haloperidol (1.5 mg/kg per day) for 12 weeks. Vacous chewing movements (VCM) were monitored, as was striatal NOS activity. Aging significantly increased spontaneous VCM in mature and aged animals and progressively attenuated NOS activity in both mature adult and aged rats compared to young animals, and numerically lower in aged versus mature adult animals. Haloperidol significantly increased VCM in all age groups, while significantly reducing NOS activity in young and mature adults but not aged. Reduced NOS activity after haloperidol treatment was significantly lower in mature compared to young rats, but only numerically lower in aged rats receiving the drug, with a slight increase noted in the latter. In the current model, aging did not markedly alter haloperidol-induced VCM. Abrogated striatal nitrergic activity, therefore, underlies aging and haloperidol-induced VCM. Compensatory nitrergic mechanisms may preclude progressive NOS suppression and dyskinesia under conditions of advanced age and NOS inhibition.

Risperidone-responsive segmental dystonia and pallidal deep brain stimulation

A 67-year-old man with risperidone-responsive segmental dystonia underwent bilateral deep brain stimulation (DBS) of the globus pallidus internus. Prospectively, the authors assessed the Burke-Fahn-Marsden Dystonia Rating Scale in medication (M) and stimulation (S) "on"/"off" states. With DBS at 9 months, the score improved by 86% to 8.5 in M-"on"/S-"on" and 12.5 in M-"off"/S-"on." Studies of the effects of DBS and concomitant medication may be warranted in selected patients treated by DBS for dystonia.

Effects of haloperidol and atypical neuroleptics on psychomotor performance and driving ability in schizophrenic patients. Results from an experimental study

The influence of antipsychotic treatment on the neuropsychological and psychomotor performance of schizophrenic patients is still a subject of investigation. The present study was designed to evaluate the effects of atypical neuroleptics in comparison with a conventional dopamine antagonist neuroleptic (haloperidol) on several dimensions of psychomotor performance (visual perception, attention, reaction time, and sensorimotor performance) considered to be of relevance in evaluating driving fitness. Psychomotor performance was assessed by means of the ART 90, a computerized Act and React Test which is generally used in diagnosis of psychomotor performance. The 49 participating patients were examined at discharge following psychopathological stabilisation; 20 received haloperidol, 29 received an atypical neuroleptic. Our findings demonstrate a remarkably reduced psychomotor performance in the haloperidol-treated group of schizophrenic patients compared with patients treated with atypical neuroleptics. Only 1 (5%) subject passed all subtests without major failures and could be regarded as competent to drive. Among patients with atypical neuroleptics, 7 patients (24%) passed all test parameters without major failures.

The effect of dopamine type-2 receptor blockade on autonomic modulation

Dopamine2 (D2)-like receptor antagonists are widely used for the treatment of gastroparesis and vomiting. Metoclopramide (MCP), a peripheral and central D2-like receptor antagonist, stimulates the sympathetic nervous system and may alter autonomic modulation, but the net effect of MCP to the heart is not known. The aim of our study was to investigate the effects of MCP on cardiac autonomic modulation, using power spectral analysis of heart rate variability. We evaluated the effect of MCP on cardiac autonomic modulation during prolonged supine and standing positions in 9 healthy men. We intravenously administered 10 mg MCP and placebo in a double blind and crossover manner to all participants during continuous electrocardiography recording. Placebo or MCP was administered after 15 minutes in supine position (REST phase), where participants remained for an additional 50 minutes (PSUP phase) and then stood up for 10 minutes (STA phase). Five-minute intervals were selected for power spectral analysis, and average values were calculated for low frequency (LF), normalized unit of LF (LFnu), high frequency (HF), normalized unit of HF (HFnu) components of the power spectrum, and for LF/HF ratio.Heart rate alterations were statistically significant during placebo administration (Friedman's p < 0.0001). These changes were related to the decrease in PSUP phase and increase in STA phase in post hoc analyses. There was a trend toward lower LFnu in PSUP phase (Friedman's p = 0.050), but LF/HF ratio changes did not reach a statistically significant level during placebo administration. MCP administration prevented the decrease in heart rate and LFnu component was seen with placebo in PSUP phase. Heart rate alterations also reached a significant level during MCP administration (Friedman's p = 0.002), and post hoc analyses showed that these changes were mainly related to the increase in STA phase. In contrast to placebo, MCP administration resulted in significant alterations in LFnu and LF/HF ratio (Friedman's p = 0.004 and p = 0.003, respectively). Two-way ANOVA model for LF/HF ratio changes showed that MCP induced a significant upward shift in LF/HF ratio than placebo during each phase of the study (F = 5.570; p = 0.031). We concluded that the net effect of MCP on sympathovagal balance is an increased sympathetic drive to the heart. MCP prevented the decrease in sympathetic drive to the heart during prolonged supine position and augmented sympathetic drive to the heart during mild sympathetic stimulation such as induced by standing up.

Relationship of orofacial movements to behavioural repertoire as assessed topographically over the course of 6-month haloperidol treatment followed by 4-month withdrawal

RATIONALE

Late-onset vacuous chewing movements (VCMs) arise in a significant proportion of rats treated chronically with conventional antipsychotic drugs. Given their common action to block dopamine D2-like receptors, VCMs may be related to changes in dopaminergic function; if so, other typical dopamine-mediated behaviours might be altered also.

OBJECTIVE

To examine this hypothesis, behavioural repertoire was studied topographically over the course of chronic treatment and withdrawal.

METHODS

Animals were injected with haloperidol decanoate 28 mg/kg IM, or vehicle, every 3 weeks for 27 weeks, and then maintained without treatment for a further 18 weeks. Immediately before each injection and during withdrawal, VCMs and other topographies of behaviour were assessed.

RESULTS

In both control and haloperidol-treated rats, exploratory behaviours declined over the study, indicating habituation effects. Conversely, VCMs emerged after 6 weeks of treatment with haloperidol and persisted after withdrawal; VCM and locomotion were not related, indicating that in treated rats, increased VCMs are not an artifact of reduced locomotion. Treated animals with VCMs evidenced increases in buccal tremor and grooming behaviour relative to those without VCMs, although no clear relationship to the emergence of VCMs was established; there were no material differences in any other topographies of behaviour.

CONCLUSION

The effect of long-term treatment with haloperidol to induce VCMs is not reflected in fundamental changes in dopamine-mediated behavioural topography but, rather, appears to affect neural mechanisms involved in orofacial movement preferentially.

[Safety and efficacy of olanzapine versus perphenazine in patients with schizophrenia: results of multicenter, 18-week, double-blind clinical trial]

AIM

The primary objective of the study was to evaluate the severity of extrapyramidal symptoms during treatment with olanzapine (10-20 mg) versus perphenazine (8-40 mg) using the Simpson Angus Scale (SAS). The secondary objective was to assess the safety profile and clinical efficacy of the investigated drugs.

MATERIAL AND METHOD

A total of 95 patients with schizophrenia who met the criteria for DSM-IV were randomized to a double-blind, 18 week prospective comparative trail conducted in Poland. The tolerance of treatment was assessed with the use of scales: BAS, SAS and UKU. The efficacy of treatment was evaluated with BPRS, PANSS and CGOI scales.

RESULTS

For olanzapine patients, the severity of extrapyramidal symptoms improved after 3 first weeks of treatment, and significantly decreased from the baseline to endpoint. Perphenazine patients showed an increase of extrapyramidal symptoms. The difference of the SAS scores change was statistically significant between olanzapine and perphenazine groups. Akathisia symptoms decreased significantly in the olanzapine group during the treatment period, whereas symptoms of akathisia increased in the perphenazine group. Statistically significant differences of mean change of BAS total score from baseline to endpoint were noted between treatment groups Treatment--emergent adverse events occurred more frequently in patients receiving perphenazine (46%), than in patients receiving olanzapine (17%). The proportion of patients complying with improvement criteria for CGI scale score was statistically greater in the olanzapine group (72.7%) than in the perphenazine group (47.9%). Results of this study showed that the tolerance profile in patients taking olanzapine is superior to perphenazine.

CONCLUSIONS

Olanzapine was better tolerated than perphenazine. After olanzapine treatment more subjects fulfilled the criterion of improvement and schizophrenic symptoms were less severe than in patients treated with perphenazine.

Pimozide injections into the Nucleus accumbens disrupt maternal behaviour in lactating rats

In rodents ongoing maternal behaviour requires activation of dopamine receptors. Therefore, it is possible that some motor components of maternal behaviour might be mediated by concurrent dopaminergic stimulation. It has been previously demonstrated that peripheral injections of some antipsychotic drugs such as pimozide have disruptive effects on maternal behaviour. The present experiments were designed to verify the effects of pharmacological blockade of limbic dopamine receptors on ongoing maternal behaviour in lactating rats. The hypothesis that central injections of the drug pimozide would have an effect on maternal behaviour was tested. We investigated the effects of central bilateral intra-accumbens microinjections of the dopamine D2 receptor antagonist pimozide (1.5 and 3.0 microg) on maternal behaviour. Animals treated with 3.0 microg of pimozide showed significantly longer latencies for all parameters of maternal behaviour compared to controls. These results suggest that dopamine receptors in the nucleus accumbens play a role in ongoing maternal behaviour.

Restless legs syndrome and drug-induced akathisia in headache patients

The purpose of the research presented in this article was to characterize restless leg syndrome (RLS) in a headache population and correlate treatment induced risks with dopamine blockers. Fifty patients with severe headache who were admitted to an outpatient infusion center were enrolled. The diagnosis of RLS was established using the International Restless Leg Syndrome Study Group criteria. Patients were screened for baseline akathisia using an akathisia scale and reexamined for akathisia after receiving intravenous infusion with one of four dopamine receptor blocking agents as treatment for their headaches. A change from baseline to post-infusion assessment of two points on a global assessment of akathisia was considered positive for drug-induced akathisia. Our results indicated that 41 (82%) of patients had episodic or chronic migraine. The rest had new daily persistent headache, cluster, or posttraumatic headache. Seventeen subjects (34%) met the criteria for RLS. Nineteen (38%) of the subjects developed drug-induced akathisia. Thirteen (76.5%) of the subjects with RLS developed akathisia compared with only 6 of the 33 (18.2%) without RLS (P<.0001). Finally, we concluded that headache patients with RLS are at a greatly increased risk of developing drug-induced akathisia when treated with intravenous dopamine receptor blocking agents.

Enhancement of serotonin-1A receptor dependent responses following withdrawal of haloperidol in rats

Although haloperidol is widely prescribed for the treatment of schizophrenia, its beneficial effects are accompanied by extrapyramidal side effects (EPS). In view of a role of 5-hydroxytryptamine (5-HT; serotonin)-1A receptors in the elicitation of EPS, the present study concerns pre- and postsynaptic responses to a selective 5-HT-1A receptor agonist, 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) following acute and chronic administration of haloperidol in rats. In the acute administration study, effects of 8-OH-DPAT (0.5 mg/kg) were monitored 30 min after single injection of haloperidol (5 mg/kg). In the chronic administration study, effects of 8-OH-DPAT (0.5 mg/kg) were monitored 48 h after withdrawal from repeated (two times a day for 2 weeks) administration of haloperidol (5 mg/kg). The intensity of 5-HT syndrome elicited by 8-OH-DPAT was taken as measure of postsynaptic response. 8-OH-DPAT-induced decreases of 5-HT synthesis were taken as measure of presynaptic response. Results showed that 8-OH-DPAT-induced locomotion was smaller in acute haloperidol-treated rats. Conversely, these effects of 8-OH-DPAT were greater in chronic haloperidol-treated rats. Animals injected acutely or chronically with haloperidol exhibited greater 5-HT synthesis in the striatum. Administration of 8-OH-DPAT did not decrease 5-HT synthesis in the striatum of acute haloperidol-treated rats but decreased it in the striatum of chronic haloperidol-treated rats. The results show an increase in the effectiveness of pre- and postsynaptic 5-HT-1A receptor dependent responses following chronic administration of haloperidol. A causal role of 5-HT-1A receptor responsiveness in the greater incidences of EPS in patients treated with typical neuroleptics such as haloperidol is discussed.

Long-term effectiveness of risperidone and olanzapine in resistant or intolerant schizophrenic patients. A mirror study

OBJECTIVE

To evaluate the long-term effectiveness of the second generation antipsychotics, risperidone and olanzapine on hospitalization, clinical response, and adherence to therapy after switching from conventional antipsychotics or clozapine in a naturalistic setting of schizophrenic patients.

METHOD

Data were registered for periods of identical duration before and after switching.

RESULTS

Fifty-seven patients were included. Mean study period was 3.1 +/- 0.2 years. Mean number of in-patient days after switching declined by 78% of the level before switching (P=0.0002). There was no significant differences in ratio responders/non-responders between the subgroups. The number of patients with extrapyramidal symptoms (EPS) was significantly reduced after switching. However, intolerable weight gain led to a lack of adherence to therapy in 18% of the olanzapine-treated patients.

CONCLUSION

Long-term treatment with the second generation antipsychotics, risperidone and olanzapine significantly improved the clinical outcome. However, weight gain may be a significant reason for discontinuation of treatment and reducing the long-term adherence to therapy.

A placebo-controlled trial of risperidone in Tourette syndrome

OBJECTIVE

To evaluate the efficacy and safety of risperidone in children and adults with Tourette syndrome.

METHODS

This was an 8-week, randomized, double-blind, placebo-controlled trial. The primary outcome measure was the Total Tic score of the Yale Global Tic Severity Scale (YGTSS).

RESULTS

Thirty-four medication-free subjects (26 children and 8 adults) ranging in age from 6 to 62 years (mean = 19.7 +/- 17.0 years) participated. YGTSS Total Tic scores were similar at baseline (26.0 +/- 5.1 for risperidone vs 27.4 +/- 8.5 for placebo). After 8 weeks of treatment (mean daily dose of 2.5 +/- 0.85), the 16 subjects on risperidone showed a 32% reduction in tic severity from baseline, compared to a 7% reduction for placebo patients (n = 18) (F[2,64] = 6.07; p = 0.004). The 12 children randomized to risperidone showed a 36% reduction in tic symptoms compared to an 11% decrease in the 14 children on placebo (F[2,48] = 6.38; p = 0.004). Two children on risperidone showed acute social phobia, which resolved with dose reduction in one subject but resulted in medication discontinuation in the other. A mean increase in body weight of 2.8 kg was observed in the risperidone group compared to no change in placebo (F[2,64] = 10.68; p = 0.0001). No extrapyramidal symptoms and no clinically significant alterations in cardiac conduction times or laboratory measures were observed.

CONCLUSION

Risperidone appears to be safe and effective for short-term treatment of tics in children or adults with Tourette syndrome. Longer-term studies are needed to evaluate the durability of efficacy and safety over time.

[Rat behavior in the "open field" next day after haloperidol injection: dependence on experimental conditions]

Wistar rats were injected with haloperidol (3.5 mg/kg) that resulted in a high level of cataplexy. Next day after haloperidol injection rat behavior was studied in the open field. The animals were divided in two groups. The first group of animals was tested in the daylight without additional illumination of the open-field chamber. The second group was tested in a darkened room with additional intense illumination of the open-field center with a 60W bulb. The testing time was 240 s. The high level of the open-field locomotor activity in the first group was attributed to anxiety. The low level of locomotor activity in the second group was qualified as depressive state.

The ability of new non-competitive glutamate receptor blockers to weaken motor disorders in animals

The ability of mono- and dicationic phenylcyclohexyl derivatives, which are non-competitive glutamate antagonists, to prevent convulsions induced in mice by intragastric NMDA or kainate, to weaken catalepsy induced in rats by haloperidol and to exert their own influences of movement activity and behavior in animals was studied. The actions of study compounds were compared with those of the known NMDA antagonists memantine and dizocilpine. NMDA-induced convulsions were effectively prevented by both mono- and dications, while only dications were effective against kainate convulsions. Anticataleptic activity was significantly more marked in monocations, which lacked the ability to block non-NMDA receptors. Side effects on motor coordination were less marked with study compounds than with dizocilpine. Thus, the effects of phenylcyclohexyl derivatives in in vivo experimental models correlate with their anti-NMDA and anti-AMPA activity. They can be regarded as potential agents for treating parkinsonism and other motor disorders.

JL 13, an atypical antipsychotic: a preclinical review

The extensive pharmacological evaluation of JL 13 as an atypical antipsychotic drug has revealed a close similarity to clozapine, however with some major advantages. JL 13 was characterized as a weak D(2) antagonist, both in vitro and in vivo, with a strong affinity for the D(4) and the 5-HT(2A) receptors. It has no affinity for the 5-HT(2C) receptor. In vivo microdialysis experiments in rat showed that JL 13, like clozapine, preferentially increased extracellular dopamine concentrations in the prefrontal cortex compared to nucleus accumbens or striatum. Behavioral studies showed that JL 13, like clozapine, has the profile of an atypical antipsychotic. Thus, JL 13 did not antagonize apomorphine-induced stereotypy nor did it produce catalepsy, but it antagonized apomorphine-induced climbing in rodents. It was inactive against d-amphetamine-induced stereotypy but antagonized d-amphetamine-induced hyperactivity in the mouse. Likewise, in the paw test, it was more effective in prolonging hindlimb retraction time than prolonging forelimb retraction time. Like other antipsychotic drugs, JL 13 reversed the apomorphine- and amphetamine-induced disruption of prepulse inhibition. In a complex temporal regulation schedule in the dog, JL 13 showed a high resemblance with clozapine without inducing sialorrhea, palpebral ptosis or any significant motor side effects. In rats and squirrel monkeys JL 13 induced a high degree of generalization (70%) to clozapine. Regarding behavioral toxicology, JL 13 did not produce dystonia or Parkinsonian symptoms in haloperidol-sensitized monkeys. After acute administration, again like clozapine, JL 13 induced only a transient increase in circulating prolactin. Last but not the least, regarding a possible hematological toxicity, unlike clozapine, JL 13 did not present sensitivity to peroxidase-induced oxidation. Moreover, its electrooxidation potential was close to that of loxapine and far from that of clozapine. Taking all these preclinical data into account, it appears that JL 13 is a promising atypical antipsychotic drug.

Antipsychotic drug-induced movement disorders

Very early in the process of diagnosing abnormal involuntary movement (AIM) disorders, one can be rewarded by keeping a high index of suspicion for possible drug-induced causes, not only through a complete list of current medications, but also identification of the drugs the patient used to take and other possible offending medications that might be available from family members and other sources. Among drug-induced movement disorders, antipsychotic drugs and other dopamine receptor blocking agents occupy a central place. Their various acute and tardive motor complications provide the template of this short review. Movement disorders caused by antidepressants, lithium, antiemetics, antiparkinsonian agents, anticonvulsants, calcium channel blockers, sympathomimetics and others are only briefly covered in table form.

Morphine and d-amphetamine nullify each others' hypothermic effects in mice

We have examined the effects of the psychostimulant d-amphetamine and the neuroleptic haloperidol on hypothermia induced by intraperitoneal injection of the centrally penetrating opioids morphine, fentanyl and sufentanil and the peripherally acting opioid loperamide. Measuring rectal body temperatures, dose-response relationships were established for all compounds. Morphine and sufentanil produced hyperthermia at low doses and dose-related hypothermia at higher doses. Fentanyl and loperamide produced dose-related hypothermia. Fixed doses of each opioid producing significant hypothermia were selected for interaction studies. The psychostimulant d-amphetamine was found t o produce biphasic effects with low doses inducing hypothermia and higher doses inducing hyperthemia. Haloperidol produced dose-related hypothermia. The selected doses of the opioids were then injected followed after 15 min. by injection of hypothermia producing doses of d-amphetamine or haloperidol. Hypothermia induced by morphine, fentanyl and sufentanil was reversed by d-amphetamine whereas loperamide-induced hypothermia was unaffected. Rebound hyperthermia was also measured with fentanyl and sufentanil. Haloperidol increased the hypothermic effects of morphine, fentanyl and sufentanil but not of loperamide. In conclusion, the central stimulating effects of opioids and amphetamine may combine resulting in thermogenesis and reversal of hypothermia. Central mechanisms of opioid-induced hypothermia in mice are influenced by drugs which alter the dopamine system, whereas peripheral mechanisms are unaffected. A possible clinical implication for this dopaminergic interaction may be toxicity associated with hyperpyrexia caused by psychostimulant misuse, which is increasingly occurring concomitantly with abuse of opioids.

Acute migraine treatment with droperidol: A randomized, double-blind, placebo-controlled trial

BACKGROUND

The treatment of a migraine attack can be difficult when first-line medication is unsuccessful and options for parenteral "rescue" therapy are limited.

METHODS

A randomized, double-blind, placebo-controlled, dose-ranging, multicenter study was conducted to assess the efficacy and tolerability of droperidol 0.1 mg, 2.75 mg, 5.5 mg, and 8.25 mg for the acute treatment of moderate to severe migraine headache in adults.

RESULTS

A total of 331 patients were enrolled; 305 were treated. Headache response at 2 hours was better (p < 0.002) in the treatment groups receiving droperidol IM at doses of 2.75 mg (87%), 5.5 mg (81%), and 8.25 mg (85%) compared with placebo (57%). The percent of patients achieving a pain-free response at 2 hours after treatment was significantly greater than placebo for the droperidol 2.75-mg, 5.5-mg, and 8.25-mg dose groups. The frequency of headache recurrence (within 24 hours) for patients initially responding by 2 hours was lower in patients treated with droperidol than placebo, but differences failed to reach significance. A significantly greater percentage of patients receiving droperidol 2.75 mg reported the elimination of migraine-associated symptoms (nausea, vomiting, photophobia, and phonophobia) than those who received placebo. Although most adverse events were of mild or moderate intensity, anxiety, akathisia, and somnolence were rated as severe in 30% of patients who experienced those symptoms. Hypotension was uncommon. No patient had QT prolongation.