Experience with injectable long-acting risperidone in long-term therapy after an acute episode of schizophrenia: the SPHERE Study

Background: Risperidone long-acting injectable (RLAI) is the first long-acting formulation of an atypical antipsychotic introduced into clinical practice. RLAI combines the benefits of atypical antipsychotic agents with an extended duration of activity and is intended for long-term management of schizophrenia. This study evaluated the use of RLAI as part of a long-term management strategy in patients with an acute episode of schizophrenia. Objectives: The primary objective was to determine clinicians' approaches to the use of RLAI in patients with an acute exacerbation of schizophrenia by examining the prescribing patterns of antipsychotic and other psychotropic medications. Other objectives were to evaluate the overall safety of switching patients to RLAI from previous antipsychotic therapy and to determine patients', caregivers' and relatives' attitudes towards RLAI treatment. Methods: The Safety and Profile of Handling and Employing of Risperdal (R) Consta (R) in Emergency/Acute Care Settings (SPHERE) study was an observational, non-interventional, multicenter, retrospective study involving a large cohort of patients with acute psychotic exacerbation who attended Spanish emergency/acute care facilities (between August and December 2003) and were treated with RLAI during hospitalization. Results: A total of 1232 patients (70% men; mean age 37 years; median of 8 months since most recent admission) were included in the analyses; 79% had been receiving antipsychotic therapy prior to admission. All patients received RLAI post-stabilization. The main reasons for initiating RLAI were the need for long-term treatment (76%) and a low adherence to previous treatment (71%). RLAI doses administered during hospitalization were: 25 (26%), 37.5 (29%), 50 (42%) and 75-100 mg (3%). The mean number of injections per patient (2 1) and mean hospitalization time (25 +/- 16 days) indicated that RLAI was administered every 2 weeks as per the manufacturer's recommendations. All patients were discharged on RLAI treatment; 62% were prescribed concomitant therapy, mainly oral risperidone (39%), anxiolytics (25%), antiparkinsonians (15%), hypnotics (11%) and anticonvulsants (11%). Only 5.7% of patients reported adverse events, most commonly extrapyramidal symptoms (1.1%) and somnolence (0.9%). Conclusions: As part of a long-term management strategy aimed at improving treatment adherence in schizophrenic patients, RLAI was prescribed to a wide spectrum of patients with an acute episode of schizophrenia during hospitalization and at the time of discharge from emergency/acute care facilities. RLAI was well tolerated in the study population and the overall impression of patients, primary caregivers and relatives to RLAI therapy was positive.