Psychiatria pre prax 1/2011

Do we know how to dose Risperdal Consta?

Non-adherence was the main reason for development of depot (= long-acting injections, LAI) antipsychotics. Risperdal Consta is the first available LAI of 2nd generation antipsychotics. Czech Republic has participated at the study e-STAR (electronic Schizophrenia Treatment Adherence Registry), an international, prospective, observational study assessing use of Risperdal Consta in a normal clinical practice setting. This analysis deals with dosage of Consta and compares dosing patterns from e-STAR in Czech Republic with other European countries. Methods: Treatment related data were collected at baseline and at 3 month intervals for 24 months. Further, illness severity as measured by Clinical Global Impression Severity (CGI-S) was included. Results: In CR a total of 609 patients (mean age 37.2 ± 12.6 y; mean duration of disorder 8.4 ± 8.8 y) were included. The main reasons for switching to Consta were non-adherence (40.3 %) and insufficient response (25.8 %). At baseline 84.2 % of patients were initiated on 25 mg, 11.3 % on 37.5 mg and 4.4 % on 50 mg of Consta every 2 weeks. At 24 months the proportion of patients on 25 mg had decreased to 54.6 %, the proportion of patiens on 37.5 mg increased to 27.2 % and on 50 mg to 17.9 %. When comparing with pooled results from other European countries participating in e-STAR the doses in CR were lower. In CR the mean dose per patient at baseline was 27.5 mg compared to 32.8 mg and 33.6 mg in other European countries. At 24 months the mean dose was 33.0 mg vs 43.6 mg and 42.3 mg in other European countries. Mean CGI-S score at baseline was 4.61 ± 1.0 and significantly improved to 2.96 ± 1.01 (p > 0.001) at 24 months. Conclusions: Data from e-STAR shows that treatment with Consta in CR was usually initiated with a low dose and starting dose was not changed in two thirds of patients. Also the mean dose at 24 months was lower in comparison with other countries. Regardless lower dosage the severity of illness decreased significantly.

Keywords: schizophrenia, risperidone long-acting injection, Risperdal Consta, dosing.