title: Fine-tuning risperidone dosage for acutely exacerbated schizophrenia: clinical determinants.
abstract: BACKGROUND
  Risperidone doses for acute schizophrenia were rather high in most recent studies.
  
  
  OBJECTIVE
  We tested a hypothesis that fine-tuning risperidone dosage to relieve side effects still yields efficacy. Clinical factors influencing the dosing were also determined.
  
  
  METHODS
  One hundred and forty-six schizophrenia inpatients with acute exacerbation entered a prospective, 6-week, repeated measures study. Risperidone doses were titrated to 6 mg/day (if tolerable) within 7 days, but were lowered thereafter if adverse reactions appeared. Efficacy and safety were measured biweekly.
  
  
  RESULTS
  Forty-eight patients tolerated the 6-mg/day target dose well, while the other 98 received lower final doses (mean+/-SD=3.4+/-0.9 mg/day) to curtail adverse effects. At endpoint, 64.3% of the low-dose patients and 43.8% of the high-dose subjects responded to treatment [>/=20% reduction in the Positive and Negative Syndrome Scale (PANSS) total score] ( P=0.018). In detail, the low-dose individuals were significantly superior in percentage changes in the PANSS total and general-subscale scores at endpoint. The low-dose group also tended to improve more (albeit statistically insignificantly) in the PANSS positive and negative subscales and other efficacy measures. Compared to the patients with undifferentiated subtype, those with disorganized subtype received higher dosage by 0.90 mg/day, after controlling for other variables ( P=0.008). Paranoid subtype was similar to undifferentiated subtype in drug doses. Patients with longer illness duration also showed a trend to use higher dosage ( P=0.078).
  
  
  CONCLUSIONS
  These findings suggest that dosage adjustment to diminish side effects does not compromise risperidone response and that disorganized patients and perhaps patients with longer illness duration are prone to receive larger doses.
authors.affiliation: Department of Psychiatry, China Medical University and Hospital, No. 2 Yuh-Der Road, 404 Taichung, Taiwan.
authors.forename: Hsien-Yuan
authors.initials: HY
authors.lastname: Lane
authors.forename: Yue-Cune
authors.initials: YC
authors.lastname: Chang
authors.forename: Chih-Chiang
authors.initials: CC
authors.lastname: Chiu
authors.forename: Sue-Hong
authors.initials: SH
authors.lastname: Lee
authors.forename: Cher-Yeang
authors.initials: CY
authors.lastname: Lin
authors.forename: Wen-Ho
authors.initials: WH
authors.lastname: Chang
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000008:administration & dosage* / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D011446:Prospective Studies; D018967:Risperidone / Q000008:administration & dosage* / Q000627:therapeutic use*; D012559:Schizophrenia / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents; D018967:Risperidone