Prospective, open study of long-acting injected risperidone versus oral antipsychotics in 88 chronically psychotic patients.

INTRODUCTION: A long-acting, injected, carbohydrate-microsphere preparation of risperidone (RLAI; Risperdal Consta ((R))) is reported to be safe and effective in chronic psychotic illnesses but, as its long-term and comparative efficacy remain unclear, this study compared clinical status during oral antipsychotic treatment versus conversion to RLAI.

METHODS: Psychotic patients (n=88; initial BPRS=93+/-5) were treated for 6 months with clinically chosen oral medication and then converted to biweekly RLAI for the first 6 months (6-6 months matched mirror comparison) and then for another 18 months. Clinical status in the two treatment periods and in the 18 months of follow-up was compared with measures including BPRS improvement (primary outcome), CGI variants and SF-36 ratings.

RESULTS: RLAI (at a mean dose of 47 mg/2 weeks at six and up to 23.1+/-3.3 months) was associated with major improvements in all outcome measures (p<0.001). Initial BPRS scores fell by an average of 50% within six months; hospitalizations declined from 19.8% to 0%, and rates of adverse events were reduced by 2.5- to 7.4-fold. Such benefits were sustained during 18 months of follow-up with RLAI-treatment.

CONCLUSIONS: The findings are limited by the lack of a parallel control treatment, such as with oral risperidone or another antipsychotic, lack of blinded assessments, and a moderate number of subjects. Nevertheless, the findings add to indications that RLAI can be an effective and well-tolerated treatment-option for chronically psychotic patients.