Influences of patient-related variables on risperidone efficacy for acutely exacerbated schizophrenia: analyses with rigorous statistics.

Response predictors of risperidone or other newer atypical antipsychotics for schizophrenia treatment remain unclear. This study aimed to investigate the influence of patient demographics on risperidone efficacy for schizophrenia. One hundred twenty-one newly hospitalized patients who had schizophrenia with acute exacerbation entered this prospective, 6-week risperidone trial. The target dose was 6 mg/day, or lower in case of side effects. Consequently, the mean +/- SD dose remained quite stable after week 2 and reached 4.4 +/- 1.3 mg/day at week 6. Efficacy and side effect assessments were conducted biweekly. The mean total score of the Positive and Negative Syndrome Scale (PANSS) declined during the trial, particularly within the first 4 weeks. Further, of the various efficacy scores (and their natural logarithm values) collected, only the logarithm of the PANSS total score was selected to serve as the response value, because it was normally distributed and thus suitable for regression analyses. After adjusting the effects of treatment duration (weeks 0-6) and other patient-related variables with the generalized estimating equation method, each 1-week increase in duration of prior hospitalizations raised the PANSS total by 0.04% (p = 0.002) and each 1-year increment in the education duration decreased the PANSS by 0.94% (p = 0.04). Gender, age, age at illness onset, duration of illness, diagnosis subtype, or number of prior hospitalizations, however, did not significantly impact the response value. These preliminary results suggest that longer hospitalization duration and shorter education predict higher symptomatology. Further studies with longer observation and larger samples in not only acutely ill patients but also other populations (e.g., first-episode patients) are warranted.

Shifting from haloperidol to risperidone for behavioral disturbances in dementia: safety, response predictors, and mood effects.

For agitated dementia showing insufficient response to conventional antipsychotics, the feasibility of transition to atypical agents remains unknown. Sixty-two Chinese inpatients with dementia and disruptive behaviors were recruited into an 8-week screening trial of haloperidol. Thirty-five (56%) of them responded insufficiently. They then entered a prospective, 16-week, open-labeled study. Haloperidol was abruptly shifted to risperidone 0.5 mg/day at weeks 1 to 4 and then 1 mg/day at weeks 5 to 12. At weeks 13 to 16, the regimen was shifted back to haloperidol at previous doses, mostly 1 mg/day. Safety, efficacy, cognition, and moods were evaluated at least every 4 weeks. Generalized estimating equation methods were used for determining the effects of the prognostic variables on the outcome values. Risperidone, particularly at 0.5 mg/day, was generally tolerable. The Brief Psychiatric Rating Scale (BPRS) score decreased progressively under risperidone treatment; at week 12, 16 (46%) patients showed response (>or=25% reduction in the BPRS). Patients with vascular dementia were more likely to respond than those with Alzheimer's disease ( p = 0.02). Haloperidol reinstitution resulted in no further improvement, except trend increments in motor symptoms. Risperidone also tended to benefit the performance on the Behavioral Pathology in Alzheimer's Disease Rating Scale. Six (17%) patients improved on moods and self-care with risperidone. These preliminary results suggest that crossover from haloperidol to risperidone is generally safe and effective and may produce favorable moods in agitated dementia patients. Vascular dementia is a predictor of treatment response. In contrast to the dose (1 mg/day) recommended for most white individuals, 0.5 mg/day could be tried at first in Chinese patients. Because of the design's limitations, further controlled studies are warranted.