Dopamine D2 receptor occupancy (D2RO) significantly influences the clinical effectiveness and safety of many antipsychotic drugs. Maintaining a D2RO range of 65%-80% provides the best antipsychotic effects while minimizing adverse reactions. Data from a Phase III trial were used to establish an exposure-response relationship for monthly intramuscular Risperidone ISM (75 and 100 mg) or placebo administered to adults with schizophrenia.
View Article and Find Full Text PDFAims: The aims of this study were to develop a population pharmacokinetic (PK) model for risperidone ISM® and to investigate the relationships between active moiety exposure, as described by apparent clearance (CL), and several covariates using all data from five clinical studies.
Methods: A population PK model was developed using active moiety concentrations from a study in healthy volunteers and two studies in patients with schizophrenia. Data from a comparative bioavailability study in medically stable patients and a Phase III study in patients with acute exacerbation of schizophrenia were then incorporated, using empirical Bayesian feedback and model refinement in NONMEM.