Long-term treatment of chronic schizophrenia with risperidone: a study with plasma levels.
Twenty-four chronic schizophrenic outpatients with a mean age of 37.21 years +/- 9.96 SD were treated with risperidone (RSP) at the dosage of 2-9 mg/die (mean 4.46 mg/die +/- 1.30 SD, mean 0.06 mg/kg +/- 0.01 SD) for a year. Clinical evaluation was assessed with the Brief Psychiatric Rating Scale (BPRS), Positive and Negative Symptoms Scale (PANSS), Extrapyramidal Side Effects Rating Scale (EPSE) and a checklist for Anticholinergic Side Effects (ACS) at T0, then after 1 (T1), 2 (T2), 3 (T3), 6 (T6), 9 (T9) and 12 (T12) months. RSP and 9-hydroxy-risperidone (9OH-RSP) plasma levels were determined at T12 by the HPLC method. BPRS and PANSS mean values showed a significant improvement during the study. No correlation between RSP dosage (mg/kg) and RSP, 9OH-RSP plasma levels or active moiety resulted. A positive correlation between age and active moiety was observed. A positive correlation between RSP and 9OH-RSP plasma levels was observed. A curvilinear relationship between active moiety and PANSS improvement (%) was observed. Patients with the higher PANSS amelioration showed RSP + 9OH-RSP plasma levels ranging from 15 to 30 ng/mL. RSP seems to be quite an effective drug. It seems, however, difficult to devise appropriate dose schedules and plasma level determination seems to be necessary in some cases.
Department of Clinical Psychiatry, Clinical Neuropsychopharmacology Unit, University of Milan, IRCCS Ospedale Maggiore, Via F. Sforza 35, 20122 Milan, Italy. maurimc@polic.cilea.it
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Mauri
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Laini
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Boscati
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Rudelli
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Salvi
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Orlandi
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Papa
D000328:Adult; D000367:Age Factors; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use*; D010054:Brief Psychiatric Rating Scale; D002851:Chromatography, High Pressure Liquid; D002908:Chronic Disease; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008297:Male; D008875:Middle Aged; D018967:Risperidone / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use*; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy*; D012720:Severity of Illness Index; D013995:Time; D014930:Women
D014150:Antipsychotic Agents; D018967:Risperidone