• Communications for Statistical Applications and Methods
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• v.16 no.1
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• pp.51-65
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• 2009

The purpose of a phase I clinical trial is to determine the maximum tolerated dose(MTD) of a new drug. This paper investigates the performance of standard method, continual reassessment method and accelerated titration designs in phase I clinical trials. Especially we study the precision and safety at the MTD of these methods. We utilize hyperbolic tangent function and power function to define dose-toxicity model. For each method, expected toxicity rate at MTD is computed and compared with target toxicity probability. We also suggest some modifications of these methods and show some improvements in performance.

• 대한임상약리학회:학술대회논문집
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• 1998.12a
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• pp.36-36
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• 1998

• Korean Journal of Biological Psychiatry
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• v.2 no.1
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• pp.131-139
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• 1995

Clozapine, on atypical antipsychotic drug, has been estimated to be a major improvement in the treatment-refractory schizophrenic patients. We evaluated the clozapine efficacy in the treatment of schizophrenic patients who are refractory to classic neuroleptics. The patients were assigned in a prospective, open, comparative trial for 12 weeks. Following an dose titration, 33 inpatients with treatment-refractory schizophrenia diagnosed according to DSM-III-R were given a clozapine(N=17, approximate 300-600mg/day) or haloperidol(N=16, approximate 20-30 mg/day) for 12 weeks. The clinical state was assessed before treatment, and 1st, 4th, 8th and 12th week during treatment using Brief Psychiatric Rating Scale(BPRS) and Positive and Negative Syndrome Scale(PANSS). Assessment of side effects were mode weekly using Simpson-Angus Scale for Extrapyramidal Side Effects and Adverse Events-Somatic Symptoms. Clozapine produces significant improvement than haloperidol on the BPRS and PANSS scores. 77% (13/17) of the clozapine-treated patients were categorized as responders, who showed at least 20% decrease in total BPRS scores, compared with 31% (5/16) of haloperidol-treated patients. Extrapyramidal side effects occurred in only one patient in clozapine group, but nine patients in haloperidol group. Salivation, sleepiness, constipation and hypotension were most frequent adverse effects observed in clozapine group. There was no significant changes in total WBC and neutrophil during clozapine treatment. These findings suggest that clozapine is on effective antipsychotic drug for the Korean treatment-refractory schizophrenic patients, who are nonresponsive to or unable to tolerate classcal antipsychotic drugs due to extrapyramidal side effects.