Safety and efficacy of long-acting risperidone in schizophrenia: a 12-week, multicenter, open-label study in stable patients switched from typical and atypical oral antipsychotics.

BACKGROUND

The safety and efficacy of the first long-acting injectable atypical antipsychotic, risperidone, were assessed in stable patients with schizophrenia switched from oral antipsychotic medications.

METHOD

Data were collected between July 1, 2001, and October 25, 2002. The study population included patients from clinics, hospitals, and physicians' offices. After a 4-week run-in period, symptomatically stable patients with schizophrenia (DSM-IV) who had been taking haloperidol (N = 46), quetiapine (N = 45), or olanzapine (N = 50) received 25 mg of long-acting risperidone. The oral antipsychotics were continued for 3 weeks after the first injection of long-acting risperidone. Injections were administered every 2 weeks at 25 mg up to a maximum dose of 50 mg for 12 weeks in this multicenter, open-label study.

RESULTS

Long-acting risperidone was well tolerated. Of the 141 patients who participated in the study, the most frequently reported adverse events were insomnia (16%), headache (15%), psychosis (11%), and agitation (11%). The mean increase in body weight was 0.4 kg. No other clinically relevant laboratory abnormalities or significant electrocardiogram changes were observed during the 12-week treatment. Extrapyramidal Symptom Rating Scale total scores were reduced during treatment with long-acting risperidone. Improvements in symptoms of schizophrenia were observed with long-acting risperidone at week 4 and continued through the 12-week treatment with significant reductions in total Positive and Negative Syndrome Scale (PANSS) scores at week 8 (-2.5, p <.01) and week 12 (-3.9, p <.001). At endpoint, 37% (50/135) of these stable patients were rated as clinically improved (> or = 20% decrease in PANSS total scores).

CONCLUSIONS

Switching treatment from oral antipsychotics to long-acting risperidone without an intervening period of oral risperidone was safe and well tolerated. Long-acting risperidone also significantly reduced the severity of symptoms in these stable patients with schizophrenia.