Risperidone in the treatment of Schizophrenia

Abstract

Risperidone is a second generation antipsychotic agent, with potent serotonin 5-HT2A and dopamine D2 receptor blocking effects. Specifically, risperidone possesses a unique balance of serotonin and dopamine antagonism, namely that its affinity for 5-HT2A receptors is significantly greater than its affinity for D2 receptors. Risperidone is well-established medication, with the proven effects on positive and negative symptoms of schizophrenia. The aim of research was to establish the effectiveness and safety of risperidone in patients with schizophrenia. The sample consisted of 60 subjects, age ranged was between 18-60 years, both genders, who met the criteria for the diagnosis various types of schizophrenia, according to ICD-10 (International Statistical Classification of Diseases). They were enrolled in the study as outpatient and inpatient setting. All subjects signed informed consent before entering into this study which had been conducted at the Psychiatric Clinic, University Clinical Center Sarajevo. Study was designed for 8-week, open-label, flexible-dose observational study. The subjects had to have a total score > -40 on Positive and Negative scale -two parts of the Positive and Negative Syndrome Scale (PANSS), and to be able to discontinue current antipsychotic medications. The primary efficacy parameter was the percent of score difference between baseline and week 8 of therapy on two above-mentioned PANSS subscales. The difference was considered as significant improvement if decrease from the baseline was 20% or more. The secondary efficacy parameter was subjective clinical evaluation of efficacy with five possible answers: very good, good, moderate, not satisfactory, not possible to evaluate. It was measured at the end of observational period by the investigator. All 60 enrolled patients completed the study. After the 8 weeks of treatment, 54/60 patients (90%) had clinically significant improvement of 20% or more decreased total PANSS score (Positive and Negative subscale). In 6/60 patients (10%) clinical improvement was also reported with less of 20% decreased total PANSS score. The side effects were registered in 8/60 patients (13.32%). The mild extrapyramidal symptoms registered in 1/60 (11.66%) patients, whom dose of risperidone was reduced. Increase of prolactine in 7/60 (11.66%), patients, whose dose of risperidone also were reduced. Average weight gain was 0.84 kg. In this study Risperidone has shown very good effectiveness and safety.