Early clinical experience with risperidone long-acting injection: a prospective, 6-month follow-up of 100 patients.

Background: The use of risperidone long-acting injection (RLAI) is reasonably well supported by controlled studies. Little is known about treatment outcomes in patients receiving RLAI in clinical practice.

Method: All prescribers in the South London and Maudsley Trust, London, United Kingdom, were informed that RLAI could be ordered for suitable patients with a DSM-IV diagnosis of schizophrenia or schizo-affective disorder: those known to be noncompliant with oral atypical antipsychotics and those intolerant of the adverse effects of conventional depot antipsychotics. Prescribers provided treatment and clinical progress data at the time of each prescription. Data collected included reason for prescribing RLAI, Clinical Global Impressions scale (CGI) score, inpatient or out-patient status, and details of all medications prescribed. All treatment discontinuations were investigated. The study was conducted from August 2002 to August 2003.

Results: Outcome could be determined for 100 subjects. Seventy-nine subjects (79%) were hospitalized when RLAI was initially prescribed. Mean duration of stay before RLAI initiation was 97 days (range, 0-1492 days). Most subjects were switched to RLAI from oral atypical (58%) or conventional depot (28%) antipsychotics. The main reason given for prescribing RLAI was poor patient acceptability of previous treatments (79%). Overall, 51% of the subjects discontinued RLAI. The main reason for discontinuation was lack of effect (24 subjects). No patient-related factor predicted outcome. CGI scores improved from a mean of 4.7 to 3.6 over the study period (p <.001). Overall, 61 subjects (61%) showed an improvement in CGI scores between baseline and endpoint. Antipsychotic coprescriptions were reduced from 71% of subjects to 8%. In completers, 23 (61%) of 38 subjects beginning RLAI as inpatients were discharged. The modal dose of RLAI was 25 mg every 2 weeks.

Conclusion: RLAI was moderately effective in clinical practice as judged by attrition from treatment. CGI score changes and discharge rates also suggest moderate effectiveness. RLAI was well tolerated. Antipsychotic coprescription was infrequent.