Paliperidone palmitate 3-monthly (PP3M) has been tested in 1-year controlled studies. The aim of this study was to examine the relapse outcomes with PP3M monotherapy at 3 years in patients with schizophrenia.

This was an observational, non-interventional study of patients started on PP3M according to their clinical need. All patients had a diagnosis of schizophrenia (ICD-10 F20) and were between 18 and 65 years of age. The study took place in a mental health facility in South East London, UK.

Among the 166 patients who started PP3M, 97 (58%) met inclusion criteria and were observed for 36 months. In total, five patients (5%) experienced a relapse (defined as step-up in clinical care) while on PP3M. There were no relapses between months 18 and 36. Of the original 97 patients, 56 (58%) remained on PP3M monotherapy at 3 years, and 71 (73%) remained on either PP3M or paliperidone palmitate one-monthly. Reasons for discontinuation of PP3M included patient refusal (n = 11, 33% of discontinuations) and adverse effects in (n = 8, 24%).

PP3M is a highly effective monotherapy treatment for reducing relapse in people with schizophrenia.

Conventional depot antipsychotics can provide constant pharmacologic treatment, eliminating partial compliance and reducing relapse risk. Atypical antipsychotics, have improved clinical profiles but require daily dosing, compromising their overall effectiveness. As oral risperidone provides safety and efficacy benefits over oral haloperidol, improvements may be realized by replacing conventional with atypical agents in long-acting therapy. This report examines 50-weeks of long-acting risperidone therapy in patients previously stabilized with conventional depot antipsychotics.

A multi-center, open-label study enrolled 725 patients with schizophrenia or schizoaffective disorder, judged clinically stable and maintained on stable antipsychotic doses for ≥4 weeks. Assignment by clinician judgment to receive 25–75 mg of long-acting risperidone every 2 weeks for 50 weeks followed, with performance of standard safety and efficacy assessments. Data are presented on patients receiving conventional depot antipsychotic monotherapy at study entry.

In the 188 (25.9%) patients receiving conventional depot antipsychotic monotherapy at entry, mild-to-moderate mean (±S.D.) Positive and Negative Syndrome Scale (PANSS)-total scores improved significantly after receiving long-acting risperidone (64.2 ± 18.9 to 58.2 ± 20.3; P < 0.001). Clinical improvement of ≥20%, 40%, or 60% reduction in PANSS-total score, occurred in 52%, 34%, and 16% of patients, respectively. ESRS subjective ratings and objective physician ratings (Parkinsonism) decreased significantly (P < 0.001).

Stable patients with mild, residual symptomatology treated with conventional depot antipsychotics experienced significant improvement in psychiatric and movement disorder symptomatology following 1-year of treatment with long-acting risperidone.