Risperidone is one of a number of 'atypical antipsychotics' which are currently being marketed for the treatment of those with schizophrenia, largely on the basis of claims of improved tolerability and effectiveness compared to much cheaper conventional antipsychotics. The efficacy of risperidone has already been compared to conventional drugs, but it remains unclear how risperidone compares with other atypical antipsychotic drugs such as clozapine.
To determine the effects of risperidone compared with other atypical antipsychotic drugs for schizophrenia.
Electronic searches of Biological Abstracts (1980-1999), The Cochrane Library (Issue 1, 2000), The Cochrane Schizophrenia Group's Register (January 1999), EMBASE (1980-1999), MEDLINE (1966-1999), LILACS (1982-1999), PSYNDEX (1977-1999) and PsycLIT (1974-1999) were undertaken. In addition, pharmaceutical databases on the Dialog Corporation Datastar and Dialog services were searched. References of all identified studies were searched for further trials. Pharmaceutical companies and authors of trials were contacted.
All randomised controlled clinical trials that compared risperidone to other atypical antipsychotic treatments for schizophrenia and schizophrenia-like psychoses were included by independent assessment.
Data collection and analysis
Citations and, where possible, abstracts were independently inspected by reviewers, papers ordered, re-inspected and quality assessed. Data were independently extracted. For homogeneous dichotomous data the risk ratio (RR), 95% confidence interval (CI) and, where appropriate, the number needed to treat (NNT) were calculated on an intention-to-treat basis. For continuous data, standardised and weighted mean differences were calculated (SMD, WMD). All data were inspected for heterogeneity.
Nine studies were obtained, comparing risperidone with clozapine (five studies - largely amongst treatment resistant patients); olanzapine (three studies); and amisulpiride (one study). The research was beset by problems of high attrition rates and short term follow up.
Clozapine does seem equally acceptable to risperidone in the short term (leaving the study early, n=466, RR 1.00 CI 0.73-1.37). For most other outcomes wide confidence intervals were obtained, which meant that it was impossible to judge whether the two compounds were equally effective, or whether one was in fact superior to the other.
Olanzapine and risperidone seem broadly similar according to numbers of patients responding to treatment (40% reduction in PANSS scores: n=339, RR 1.14, CI 0.99-1.32). Olanzapine caused fewer people to leave the study early (n=404, RR 1.31 CI 1.06-1.60; NNT 8 CI 4-32) and fewer extrapyramidal side effects (n=339, RR 1.67 CI 1.14-2.46; NNH 8 CI 5-33), although comparative doses of risperidone were higher than those recommended in practice.
In one single study (n=228) amisulpiride seemed broadly similar to risperidone in most respects.
There were no useful data presented relating to service use and costs. Very few data relating to quality of life were presented.
The equivalence of clozapine and risperidone for treatment resistant schizophrenia cannot yet be assumed and there seems to be little to chose between risperidone and both olanzapine and amisulpiride. The research is limited in many respects, and longer term studies measuring clinically important outcomes, including service use and quality of life are needed to judge the comparative value of the various atypical drugs.
電子搜尋Biological Abstracts (1980 – 1999), The Cochrane Library (Issue 1, 2000), The Cochrane Schizophrenia Group's Register (January 1999), EMBASE (1980 – 1999), MEDLINE (1966 – 1999), LILACS (1982 – 1999), PSYNDEX (1977 – 1999) and PsycLIT (1974 – 1999), the Dialog Corporation Datastar 和 Dialog services的藥學資料庫. 也檢查相關試驗的文獻取得更多試驗. 連絡相關作者和藥廠.
檢閱者獨立檢視引用文獻和摘要,排序文獻再重新檢查,並檢查試驗品質. 資料獨立擷取. 由意圖治療患者群體計算同質二元資料的RR和95%CI,需要治療人數. 計算連續資料的標準平均差和加權平均差. 所有資料經過同質性檢測
找到9試驗比較risperidone, clozapine (使用於其中5個,大多為有抗藥性患者), olanzapine (3個試驗); 和amisulpiride (1個試驗). 這些試驗都有退出率太高和追蹤其短的問題. 短期Clozapine 接受度的確和risperidone相當 (由退出試驗人數來看, 樣本數為466, RR 1.00 CI 0.73 – 1.37). 其他結果大部份信賴區間太寬,無法判定療效相當或其中之一療效較佳. Olanzapine 和risperidone 的治療反應率相當(定義為PANSS 評分降低40,樣本數為339, RR 1.14, CI 0.99 – 1.32). 即使risperidone組使用劑量高於一般臨床使用, Olanzapine 組仍較少受試者提早離開(樣本數為404, RR 1.31 CI 1.06 – 1.60; 需要治療人數8 CI 4 – 32) 和較少錐體外系副作用 (樣本數為339, RR 1.67 CI 1.14 – 2.46; 需要治療人數8 CI 5 – 33).1試驗(樣本數為228)顯示 amisulpiride 和risperidone 在很多方面的表現都相當. 沒有使用服務和費用資料也沒什麼生活品質資料.
無法假定clozapine 和 risperidone在治療頑抗型精神分裂症的療效相當,但risperidone, olanzapine 和amisulpiride似乎差異不大. 試驗受限,需要較長期量測臨床上重要結果(如使用服務和生活品質)的試驗,以評估各非典型藥物療效.
此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。