Comparative evaluation of pancreatic histopathology of rats treated with olanzapine, risperidone and streptozocin

Olanzapine and risperidone are widely prescribed atypical antipsychotics used in the treatment of schizophrenia and various other psychiatric disorders. Both of these drugs have been extensively reported to cause Type 2 diabetes mellitus and pancreatitis, however, the mechanism of olanzapine and risperidone-induced toxicity has not been so far unveiled. We, therefore, compared the streptozocin-induced pancreatic damage with that of pancreas isolated from olanzapine and risperidone treated rats. It was noticed that fibrotic growth, necrosis and derangement of the pancreatic islet cells caused by streptozocin were more pronounced than olanzapine and risperidone.

Estudio de biodisponibilidad comparativa de dos formulaciones de risperidona existentes en el mercado chileno / Comparative bioavailability study of two formulations of risperidone available in the Chilean market

BACKGROUND: Bioavailability of a particular drug can vary according to the formulation used. Therefore, studies of comparative bioavailability of different formulations of a same drug are worthwhile. AIM: To compare the bioavailability of two risperidone formulations available in the Chilean market. MATERIAL AND METHODS: The bioavailability of a local risperidone formulation (Spiron) was compared with the original formulation of the drug (Risperdal) in 12 healthy volunteers, aged 19 +/- 1 years. A single dose of 3 mg was given orally, using a randomized double blind protocol in two periods. Fifteen blood samples were obtained at regular intervals, until 24 h after drug administration. Risperidone plasma levels were measured by high pressure liquid chromatography. pharmacokinetic parameters were calculated using a computer program that is independent of compartmental analysis. RESULTS: The area under the curve of plasma concentration versus time, from 0 to infinite (ABC0-infinity) and from 0 to 24 h (ABC0-24), early exposure (ABC from 0 to maximal time) and maximal plasma concentrations were significantly lower for Spiron. Half life time and time to achieve the maximal concentration were similar for the two formulations. CONCLUSIONS: According to bioequivalence tests suggested by the Food and Drug Administration (FDA) of the United States (90 per cent confidence interval for the difference of long transformed mean pharmacokinetic parameters), the formulations Risperdal and Spiron, cannot be considered interchangeable.

Análisis de estudios clínicos con olanzapina / Analysis of clinical studies with olanzapine

Objetivo: Revisar las características del antipsicótico atípico olanzapina y analizar los estudios de eficacia clínica disponibles hasta ahora. Método: Se seleccionaron los trabajos más relevantes, los que fueron analizados desde el punto de vista de la eficacia clínica y de la seguridad del fármaco. Resultados: La olanzapina demostró eficacia sobre los síntomas positivos, negativos y depresivos de la esquizofrenia, mejorando la calidad de vida y disminuyendo las rehospitalízaciones. Tuvo escasos efectos colaterales y se asoció significativamente menos con la aparición de síntomas extrapiramidales y disquinesía tardía en comparación con el haloperidol. Conclusiones: La olanzapina parece representar una alternativa eficaz y segura para el tratamiento de la sintomatología esquizofrénica