Background

Risperidone is the first new generation antipsychotic drug made available in a long‐acting injection formulation.

Objectives

To examine the effects of depot risperidone for treatment of schizophrenia or related psychoses in comparison with placebo, no treatment or other antipsychotic medication.

To critically appraise and summarise current evidence on the resource use, cost and cost‐effectiveness of risperidone (depot) for schizophrenia.

Search methods

We searched the Cochrane Schizophrenia Group's Register (December 2002, 2012, and October 28, 2015). We also checked the references of all included studies, and contacted industry and authors of included studies.

Selection criteria

Randomised clinical trials comparing depot risperidone with other treatments for people with schizophrenia and/or schizophrenia‐like psychoses.

Data collection and analysis

Two review authors independently selected trials, assessed trial quality and extracted data. For dichotomous data, we calculated the risk ratio (RR), with 95% confidence interval (CI). For continuous data, we calculated mean differences (MD). We assessed risk of bias for included studies and created 'Summary of findings' tables using GRADE.

Main results

Twelve studies, with a total of 5723 participants were randomised to the following comparison treatments:

Risperidone depot versus placebo

Outcomes of relapse and improvement in mental state were neither measured or reported. In terms of other primary outcomes, more people receiving placebo left the study early by 12 weeks (1 RCT, n=400, RR 0.74 95% CI 0.63 to 0.88, very low quality evidence), experienced severe adverse events in short term (1 RCT, n=400, RR 0.59 95% CI 0.38 to 0.93, very low quality evidence). There was however, no difference in levels of weight gain between groups (1 RCT, n=400, RR 2.11 95% CI 0.48 to 9.18, very low quality evidence).

Risperidone depot versus general oral antipsychotics

The outcome of improvement in mental state was not presented due to high levels of attrition, nor were levels of severe adverse events explicitly reported. Most primary outcomes of interest showed no difference between treatment groups. However, more people receiving depot risperidone experienced nervous system disorders (long‐term:1 RCT, n=369, RR 1.34 95% CI 1.13 to 1.58, very‐low quality evidence).

Risperidone depot versus oral risperidone

Data for relapse and severe adverse events were not reported. All outcomes of interest were rated as moderate quality evidence. Main results showed no differences between treatment groups with equivocal data for change in mental state, numbers leaving the study early, any extrapyramidal symptoms, weight increase and prolactin‐related adverse events.

Risperidone depot versus oral quetiapine

Relapse rates and improvement in mental state were not reported. Fewer people receiving risperidone depot left the study early (long‐term: 1 RCT, n=666, RR 0.84 95% CI 0.74 to 0.95, moderate quality evidence). Experience of serious adverse events was similar between groups (low quality evidence), but more people receiving depot risperidone experienced EPS (1 RCT, n=666, RR 1.83 95% CI 1.07 to 3.15, low quality evidence), had greater weight gain (1 RCT, n=666, RR 1.25 95% CI 0.25 to 2.25, low quality evidence) and more prolactin‐related adverse events (1 RCT, n=666, RR 3.07 95% CI 1.13 to 8.36, very low quality evidence).

Risperidone depot versus oral aripiprazole

Relapse rates, mental state using PANSS, leaving the study early, serious adverse events and weight increase were similar between groups. However more people receiving depot risperidone experienced prolactin‐related adverse events compared to those receiving oral aripiprazole (2 RCTs, n=729, RR 9.91 95% CI 2.78 to 35.29, very low quality of evidence).

Risperidone depot versus oral olanzapine

Relapse rates were not reported in any of the included studies for this comparison. Improvement in mental state using PANSS and instances of severe adverse events were similar between groups. More people receiving depot risperidone left the study early than those receiving oral olanzapine (1 RCT, n=618, RR 1.32 95% CI 1.10 to 1.58, low quality evidence) with those receiving risperidone depot also experiencing more extrapyramidal symptoms (1 RCT, n=547, RR 1.67 95% CI 1.19 to 2.36, low quality evidence). However, more people receiving oral olanzapine experienced weight increase (1 RCT, n=547, RR 0.56 95% CI 0.42 to 0.75, low quality evidence).

Risperidone depot versus atypical depot antipsychotics (specifically paliperidone palmitate)

Relapse rates were not reported and rates of response using PANSS, weight increase, prolactin‐related adverse events and glucose‐related adverse events were similar between groups. Fewer people left the study early due to lack of efficacy from the risperidone depot group (long term: 1 RCT, n=749, RR 0.60 95% CI 0.45 to 0.81, low quality evidence), but more people receiving depot risperidone required use of EPS‐medication (2 RCTs, n=1666, RR 1.46 95% CI 1.18 to 1.8, moderate quality evidence).

Risperidone depot versus typical depot antipsychotics

Outcomes of relapse, severe adverse events or movement disorders were not reported. Outcomes relating to improvement in mental state demonstrated no difference between groups (low quality evidence). However, more people receiving depot risperidone compared to other typical depots left the study early (long‐term:1 RCT, n=62, RR 3.05 95% CI 1.12 to 8.31, low quality evidence).

Authors' conclusions

Depot risperidone may be more acceptable than placebo injection but it is hard to know if it is any more effective in controlling the symptoms of schizophrenia. The active drug, especially higher doses, may be associated with more movement disorders than placebo. People already stabilised on oral risperidone may continue to maintain benefit if treated with depot risperidone and avoid the need to take tablets, at least in the short term. In people who are happy to take oral medication the depot risperidone is approximately equal to oral risperidone. It is possible that the depot formulation, however, can bring a second‐generation antipsychotic to people who do not reliably adhere to treatment. People with schizophrenia who have difficulty adhering to treatment, however, are unlikely to volunteer for a clinical trial. Such people may gain benefit from the depot risperidone with no increased risk of extrapyramidal side effects.