Long-term studies of antipsychotic drugs in schizophrenia

A review on schizophrenia and relapse--a quest for user-friendly psychopharmacotherapy

OBJECTIVE

Schizophrenia in general is notoriously associated with relapses rendering the illness progressive to worse outcomes, a concept of which is compatible with neurotoxicity. Therefore, relapse prevention is of utmost clinical relevance.

METHODS

In this review, we aim to put relapse into clinical context in the realm of natural history of, or heterogeneity in, schizophrenia and summarize risk factors of relapse. We discuss how to effectively 'define' relapse in schizophrenia and recent meta-analytic studies on this topic to highlight the importance of continuous antipsychotic treatment.

RESULTS

The following issues emerged: 'How low maintenance antipsychotic dosage could be?’, 'How extended dosing could be?’, 'Who could be successfully withdrawn from antipsychotics?’ and 'How relapse could be defined in the first place?’ The question in particular is how better to deliver antipsychotics at the lowest possible, whereby dose and dosing interval are relevant. While ongoing antipsychotic treatment is the rule, recent works are pointing to a possibility of lower dosage in the maintenance phase of the illness.

CONCLUSIONS

Bearing in mind that suboptimal adherence and withdrawal from antipsychotics are an established and unequivocal risk factor for relapse, further investigations are certainly needed to explore user-friendly manner of psychopharmacotherapy to prevent relapse in schizophrenia.

Antipsychotic medication for early episode schizophrenia

BACKGROUND

Long-term treatment with antipsychotic medications in early episode schizophrenia spectrum disorders is common, but both short and long-term effects on the illness are unclear. There have been numerous suggestions that people with early episodes of schizophrenia appear to respond differently than those with multiple prior episodes. The number of episodes may moderate response to drug treatment.

OBJECTIVES

To assess the effects of antipsychotic medication treatment on people with early episode schizophrenia spectrum disorders.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Group register (July 2007) as well as references of included studies. We contacted authors of studies for further data.

SELECTION CRITERIA

Studies with a majority of first and second episode schizophrenia spectrum disorders comparing initial antipsychotic medication treatment with placebo, milieu, or psychosocial treatment.

DATA COLLECTION AND ANALYSIS

Working independently, we critically appraised records from 681studies, of which five studies met inclusion criteria. John Rathbone from the Schizophrenia Group supported us with the data extraction. We calculated risk ratios (RR) and their 95% confidence intervals (CI) where possible. For continuous data, we calculated mean difference (MD). We calculated numbers needed to treat/harm (NNT/NNH) where appropriate.

MAIN RESULTS

Five studies with a combined N = 998 met inclusion criteria. Four studies (N = 724) provided leaving the study early data and results suggested that individuals treated with a typical antipsychotic medication are less likely to leave the study early than those treated with placebo (Chlorpromazine: 3 RCTs N = 353, RR 0.4 CI 0.3 to 0.5, NNT 3.2, Fluphenaxine: 1 RCT N = 240, RR 0.5 CI 0.3 to 0.8, NNT 5; Thioridazine: 1 RCT N = 236, RR 0.44 CI 0.3 to 0.7, NNT 4.3, Trifulperazine: 1 RCT N = 94, RR 0.96 CI 0.3 to 3.6). Two studies (Cole 1964; May 1976) contributed data to assessment of side effects and present a general pattern of more frequent side effects among individuals treated with typical antipsychotic medications compared to placebo. Rappaport 1978 suggested a higher rehospitalisation rate for those receiving chlorpromazine compared to placebo (N = 80, RR 2.29 CI 1.3 to 4.0, NNH 2.9). However, a higher attrition in the placebo group is likely to have introduced a survivor bias into this comparison, as this difference becomes non-significant in a sensitivity analysis on intent-to-treat participants (N = 127, RR 1.69 CI 0.9 to 3.0). One study (May 1976) contributes data to a comparison of trifluoperazine to psychotherapy on long-term health in favour of the trifluoperazine group (N = 92, MD 5.8 CI 1.6 to 0.0); however, data from this study are also likely to contain biases due to selection and attrition. One study (Mosher 1995) contributes data to a comparison of typical antipsychotic medication to psychosocial treatment on six-week outcome measures of global psychopathology (N = 89, MD 0.01 CI -0.6 to 0.6) and global improvement (N = 89, MD -0.03 CI -0.5 to 0.4), indicating no between-group differences. On the whole, there is very little useable data in the few studies meeting inclusion criteria.

AUTHORS' CONCLUSIONS

With only a few studies meeting inclusion criteria, and with limited useable data in these studies, it is not possible to arrive at definitive conclusions. The preliminary pattern of evidence suggests that people with early episode schizophrenia treated with typical antipsychotic medications are less likely to leave the study early, but more likely to experience medication-related side effects. Data are too sparse to assess the effects of antipsychotic medication on outcomes in early episode schizophrenia.