Antipsychotic withdrawal symptoms "do not affect clozapine response"

05 июля, 2003
LONDON Newswire reporters Symptom exacerbation following withdrawal of typical antipsychotics does not appear to reduce the subsequent response to clozapine in treatment-resistant schizophrenic patients, say US researchers. HMG - Health Newswire Professional via NewsEdge Corporation : LONDON By Health Newswire reporters Symptom exacerbation following withdrawal of typical antipsychotics does not appear to reduce the subsequent response to clozapine in treatment-resistant schizophrenic patients, say US researchers. There has been considerable debate about whether stopping antipsychotic medication affects long-term outcome in patients with schizophrenia. Some researchers have suggested that discontinuation of antipsychotics might be harmful. This has raised the question of whether the use of placebo washouts in clinical trials of patients with schizophrenia adversely affects the benefits of subsequent medication. To address this, Drs David Pickar and John Bartko from Gabriel Pharma in Cabin John, Maryland, examined the behavioural effects of drug washout and subsequent treatment with clozapine in 50 inpatients with treatment-resistant schizophrenia. Baseline treatment with a typical antipsychotic was given for an average of six weeks, before patients began a placebo washout period, which lasted at least four weeks. After the placebo washout, clozapine was initiated at 50 mg/day and increased gradually over 2 to 3 weeks. On average, optimal treatment with clozapine was observed after about 12 weeks, using a mean dose of 450.5mg/day. Psychiatrists, who were blind to the patients medication status, used the Brief Psychiatric Rating Scale (BPRS) to measure the severity of symptoms every week. They assessed the impact of treatment by calculating the effect sizes for the BPRS total score. An effect size of 0.2 was considered small, 0.5 was medium and 0.8 was large. The researchers found that symptoms significantly worsened during the placebo washout. When patients were switched to clozapine, symptom scores were significantly better compared to baseline treatment and the placebo washout period. The effect sizes were 0.63 for baseline treatment versus placebo washout, 1.1 for optimal clozapine treatment versus placebo washout, and 0.82 for optimal clozapine treatment versus baseline treatment. The results, say the researchers, show that, although there is clinical deterioration after the discontinuation of a typical antipsychotic, this deterioration does not appear to detract from the subsequent response to clozapine. The study also confirms the value of clozapine in treatment-resistant schizophrenia, says the team. The enhanced therapeutic effectiveness of clozapine in seriously ill patients with schizophrenia was again demonstrated in this study, said Dr Pickar. Reference: Pickar and Bartko, American Journal of Psychiatry 2003;160:1133-1138 HMG Worldwide 2003 http://www.health-news.co.uk/ Publication: HMG - Health Newswire Professional Distributed by Financial Times Information Limited <> << Copyright ©2003 Financial Times Limited, All Rights Reserved >>
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