Biomedical subjects
J M Kane
Publications and source records attributed to J M Kane.
Incidence and correlates of tardive dyskinesia in first episode of schizophrenia.
BACKGROUND: There is controversy over whether tardive dyskinesia (TD) is solely a consequence of antipsychotic drug treatment or in part may reflect an intrinsic aspect of the disease process. Pathophysiologic factors could, independently or in concert with drug effects, lead to the development of dyskinetic signs. METHODS: We studied prospectively 118 patients in their first episode of psychosis who were treatment-naive or had less than 12 weeks of antipsychotic drug exposure at study entry. Patients received standardized antipsychotic drug treatment and were evaluated for up to 8 1/2 years with regular assessments of psychopathologic signs and symptoms and side effects. RESULTS: The cumulative incidence of presumptive TD was 6.3% after 1 year of follow-up, 11.5% after 2 years, 13.7% after 3 years, and 17.5% after 4 years. Persistent TD had a cumulative incidence of 4.8% after 1 year, 7.2% after 2 years, and 15.6% after 4 years. Taken individually, both antipsychotic drug dose, entered as a time-dependent covariate, and poor response to treatment of the first psychotic episode were significant predicters of time to TD. When antipsychotic drug dose and treatment response were examined together, treatment responders had significantly lower hazards for presumptive TD than nonresponders (hazard ratio, 0.29; 95% confidence interval, 0.09 to 0.97). Dose was a trend-level predicter, with each 100-mg chlorpromazine equivalent unit increase in dose associated with a 5% increase in the hazard of presumptive TD (hazard ratio, 1.05; 95% confidence interval, 0.99 to 1.11). CONCLUSION: Poor response to the treatment of a first episode of psychosis and, to a lesser extent, antipsychotic drug dose are important factors in the development of TD. This suggests that there may be a disease-related vulnerability to TD manifest with antipsychotic drug exposure. Potential pathophysiologic factors might include neurodevelopmentally induced structural neuropathologic characteristics, sensitization of nigrostriatal dopamine neurons, and the induction of glutamatergically mediated neurotoxic effects.
Impact of recent economic changes in psychiatry on academic psychiatry programs.
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Tardive dyskinesia induced by risperidone?
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Treatment of schizophrenia.
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Prevalence and clinical correlates of extrapyramidal signs and spontaneous dyskinesia in never-medicated schizophrenic patients.
OBJECTIVE: This study assessed the prevalence of extrapyramidal signs and spontaneous dyskinesia in neuroleptic-naive, first-episode schizophrenic patients and examined the clinical correlates. METHOD: In a prospective study of the psychobiology of schizophrenia, the authors examined 89 neuroleptic-naive patients for the presence of extrapyramidal signs by using the Simpson-Angus Rating Scale and for dyskinesia by using the Tardive Dyskinesia Rating Scale. RESULTS: Fifteen patients (16.9%) had extrapyramidal signs, but only one had spontaneous dyskinesia at baseline. Presence of extrapyramidal signs was correlated with more negative symptoms and poorer treatment outcome that was reflected in a longer time to and lower level of remission. There was no correlation of spontaneous extrapyramidal signs with age of patient, age at onset of psychotic symptoms, or baseline psychopathology. There was no difference between patients with and without spontaneous extrapyramidal signs in terms of the subsequent development of persistent tardive dyskinesia, but the patients with spontaneous extrapyramidal signs were more likely to develop parkinsonian side effects after 8 weeks of antipsychotic treatment. CONCLUSIONS: Extrapyramidal signs are present in a proportion of neuroleptic-naive, first-episode schizophrenic patients, which suggests an involvement of these signs in the schizophrenic process that probably reflects basal ganglia pathology. The presence of spontaneous extrapyramidal signs seems to have prognostic significance insofar as it is linked to a poorer outcome and longer time to remission. Spontaneous dyskinesia appears to be a relatively rare finding.
Plasma clozapine levels and clinical response for treatment-refractory schizophrenic patients.
OBJECTIVE: The purpose of this study was to determine if plasma clozapine levels were associated with treatment response. METHOD: To examine this question, neuroleptic nonresponsive patients with schizophrenia or schizoaffective disorder were given clozapine, which was titrated to 500 mg/day by day 14 of treatment, and the dose was held fixed at least through day 21. Subsequently, clozapine doses were adjusted as clinically indicated, up to a maximum of 900 mg/day. Plasma clozapine levels were obtained at weeks 3 and 6, and standard clinical ratings (Brief Psychiatric Rating Scale [BPRS] and Clinical Global Impression) were done at baseline and at weeks 3 and 6. RESULTS: Data from 45 subjects were analyzed. There were no correlations between plasma clozapine levels and change in BPRS scores at treatment weeks 3 and 6. However, when the subjects were classified as responders or nonresponders, therapeutic response was associated with clozapine blood levels above 350 ng/ml. CONCLUSIONS: This study suggest that clozapine blood levels are correlated with clinical response.
Neuroleptic treatment of elderly patients.
Data from an ongoing longitudinal study of the development of tardive dyskinesia were analyzed to examine the indications for neuroleptic treatment, continuity of treatment and dosage, and the effects of treatment on ratings of psychopathology and cognitive functioning during the first year of followup. Subjects were 266 elderly patients who had just begun neuroleptic treatment. Patients were predominantly (75%) female; their mean (+/- SD) age was 76.9 (+/- 9.2) years. A psychiatric diagnosis was recorded for 44 percent, primarily major depressive disorder; organic mental syndrome was diagnosed in 65 percent of the patients. Symptom ratings indicated 82 percent of the patients had psychosis, with or without agitation. Haloperidol was prescribed for 68 percent of the patients. Most were on neuroleptic medication continuously during the first month of followup; the average starting dose was 80 mg/day in chlorpromazine equivalent units. Symptom ratings at 1 month and 6 months showed significant improvement from baseline; ratings of dementia were unchanged.
Antipsychotic medication in the treatment of schizophrenia.
Antipsychotic medication remains the mainstay of both acute and long-term treatment for schizophrenia. Recent research has underscored the need for optimum dosing strategies. Relatively few patients benefit from high doses (e.g. greater than 15-20 mg per day of haloperidol or 500-800 mg/day of chlorpromazine). In poor or partial responders clozapine continues to be the treatment of choice. Risperidone is an effective antipsychotic with a good safety profile. Its potential advantages in terms of efficacy need to be further studied. An expanded data base from maintenance trials supports the use of continuing maintenance medication and provides guidelines for dosage requirements.
5-Aryl-3-(alkylthio)-4H-1,2,4-triazoles as selective antagonists of strychnine-induced convulsions and potential antispastic agents.
Selected examples from three series of isomeric (alkylthio)-1,2,4-triazoles were prepared and examined for anticonvulsant activity versus strychnine-, maximal-electroshock-, pentylenetetrazole-, and 3-mercaptopropionic-acid-induced seizures in mice. A number of 5-aryl-3-(alkylthio)-4H-1,2,4-triazoles were selective antagonists of strychnine-induced convulsions. The isomeric 3-aryl-5-(alkylthio)- and 5-aryl-3-(alkylthio)-1H-1,2,4-triazoles were essentially inactive as anticonvulsants. The most potent antagonist of strychnine-induced convulsions was 5-(2-fluorophenyl)-4-methyl-3-(methylthio)-4H-1,2,4-triazole (3s), while the most selective antagonist was 5-(3-fluorophenyl)-4-methyl-3-(methylsulfonyl)-4H-1,2,4-triazole (3aa). The anticonvulsant profiles of these 4H-1,2,4-triazoles suggested that they were acting functionally like glycine receptor agonists. Since it has recently been postulated that compounds possessing glycine-agonist-like properties might be useful in the treatment of spasticity, we examined 5-phenyl-4-methyl-3-(methylsulfonyl)-4H-1,2,4-triazole (3c) in an in vivo model of spasticity. In this regard, 3c reduced the occurrence of hyperreflexia in rats that had received spinal transections 5-10 weeks previously. While triazole 3c appeared to possess glycine-agonist-like properties in vivo, it did not displace [3H]strychnine binding from rat brain stem/spinal cord membranes in vitro. On the other hand, 3c enhanced muscimol-stimulated 36Cl influx in a rat cerebellar membrane preparation, indicating a possible interaction of these triazoles with the GABAA receptor.
Methylphenidate response, psychopathology and tardive dyskinesia as predictors of relapse in schizophrenia.
Despite the proven efficacy of acute and maintenance pharmacotherapy in schizophrenia, practical methods for identifying patients who require continuous treatment to prevent relapse have not been established. We hypothesized that a pathologic overactivity of mesolimbic and mesocortical dopamine neural systems, that mediates positive psychotic symptoms in the acute phase of the illness, persists in some outpatients who are vulnerable to relapse despite appearing clinically stable. To test and determine if putative measures of central nervous system dopamine activity predict outcome, 41 stable outpatients receiving neuroleptic maintenance treatment underwent provocative tests with methylphenidate in a randomized double-blind placebo controlled design in which behavioral, neuromotor, biochemical, and cardiovascular responses were measured. Patients were then withdrawn from medication and monitored for 52 weeks, or until relapse. The results indicate that psychotic symptoms and their activation by methylphenidate, and the presence of tardive dyskinesia are associated with each other and with a higher risk of relapse. These findings partially support our hypothesis and offer potentially useful measures for the identification of candidates for reduced dose neuroleptic maintenance treatment strategies in schizophrenia.
Clinical effects of clozapine in chronic schizophrenia: response to treatment and predictors of outcome.
OBJECTIVE: This study addressed the unique clinical properties attributed to the atypical antipsychotic clozapine, including its efficacy in patients with treatment-refractory psychosis and against negative symptoms, its lack of acute extrapyramidal side effects, and the longer time course of its therapeutic effects. METHOD: The clinical responses of 84 schizophrenic inpatients (66 with treatment-refractory illness and 18 who were intolerant of antipsychotic treatment) were examined. After all previous antipsychotic medications had been withdrawn, the patients were treated with clozapine according to a standardized titration and dosage schedule. Patients who tolerated and responded to treatment were discharged and maintained on a regimen of clozapine for up to 52 weeks. Patients were evaluated for behavioral response and side effects after weeks 3, 6, 12, 26, 39, and 52 of treatment. RESULTS: Fifty percent of the patients with treatment-refractory illness and 76% of the treatment-intolerant patients responded to clozapine in up to 52 weeks. The optimal period for a trial of clozapine appeared to be 12-24 weeks. Clozapine exhibited therapeutic effects on negative symptoms, but these were not clearly independent of its effects on positive symptoms and extrapyramidal side effects. Several variables, including early age at onset of illness and female gender, were found to be predictors of poor response to treatment. Predictors of good response included the presence of extrapyramidal side effects during previous treatment with classic neuroleptics and a diagnosis of paranoid schizophrenia. CONCLUSIONS: These findings have important implications for the use of clozapine and our understanding of the pathophysiology of treatment-resistant schizophrenia.
The use of higher-dose antipsychotic medication. Comment on the Royal College of Psychiatrists' consensus statement.
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Risperidone: new horizons for the schizophrenic patient. 9th World Congress of Psychiatry of the World Psychiatric Association, Rio de Janeiro, June 1993.
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Towards more effective antipsychotic treatment.
The development of antipsychotic drugs has followed two complementary approaches, either towards highly specific actions (e.g. on the dopamine receptor) or targeting a broad range of receptors. The properties of 'atypical' agents challenge the original dopamine hypothesis and suggest roles for a variety of dopamine receptors and for other pathways, such as serotonin. Older drugs, despite their proven efficacy in relieving many schizophrenic symptoms, have several drawbacks, being ineffective in some patients, relatively ineffective against negative symptoms, and causing adverse neurological effects which may, in turn, be associated with poor compliance. Among newer agents, currently available ones, such as clozapine and risperidone, offer the possibility of more effective control of negative symptoms and an improved side-effect profile, while others are in earlier stages of development. However, much still remains to be understood about their mechanisms of action.
Predictors of response to clozapine.
Clinical and biological measures were examined for their relationship to clinical response to clozapine. Associations were found between therapeutic response and the following variables: male gender, paranoid schizophrenia subtype diagnosis, older age at onset of illness, shorter duration of illness, higher levels of pretreatment acute EPS, low pretreatment CSF HVA/5-HIAA, greater decrease in prolactin (PRL) and increase in growth hormone (GH) response to apomorphine stimulation pretreatment and greater inhibition by clozapine treatment of PRL and GH response to apomorphine, and plasma clozapine levels above 350 ng/mL. These results are consistent with other investigators' findings and have practical and heuristic implications for the use of clozapine and understanding its mechanism of action.
Clozapine and weight gain.
BACKGROUND: To investigate the association of clozapine treatment and weight gain, we studied short- and long-term weight gain, correlation of weight gain with treatment response, and risk factors for weight gain in 82 patients with chronic schizophrenia who received clozapine treatment for up to 90 months. METHOD: Weight values were obtained through retrospective chart review. Clozapine was titrated over an average of 3 to 5 weeks up to a dose of 500 to 600 mg/day. Psychopathology was assessed with the Brief Psychiatric Rating Scale and the Clinical Global Impressions scale. RESULTS: A clinically significant weight gain occurred mostly during the first 6 to 12 months, but continued well into the third year of treatment. Weight gain and treatment response were not correlated, and early weight gain was not a predictor of response. The cumulative incidence of patients becoming substantially overweight exceeded 50%. Being underweight at baseline correlated with maximum amount gained (p = .000), and being overweight at baseline correlated with percentage above ideal weight (p = .006). CONCLUSION: Treatment with clozapine is associated with a high incidence of substantial weight gain, posing a potential long-term health risk. Studies are needed of the underlying mechanisms of weight gain, as well as the treatment for this side effect.