Early Prediction of Clinical Response in Patients With Schizophrenia Treated by Paliperidone ER

Early Prediction of Clinical Response, Metabolic Change, and Pharmacokinetics in Taiwanese Patients With Schizophrenia Patients Treated by Paliperidone ER: an Open-Label Study

Paliperidone ER is a new psychotropic medication for schizophrenia treatment. The studies of 6-week acute treatment and 52-week maintenance treatment showed positive results in patients with schizophrenia and its clinical improvement may start at Day 4. Some second-generation antipsychotics have been found that using the first 2 weeks' treatment results to predict the fourth or sixth week's treatment response is acceptable.

The primary aim of this study is to investigate:

1. . whether the early prediction model used in other atypicals could also be applied in paliperidone ER.
2. . The changes of metabolic parameters and pharmacokinetics after paliperidone ER treatment in this study

Patients diagnosed with schizophrenia or schizoaffective disorders will be enrolled in the 6-week trial. Eligible patients will receive 9mg paliperidone ER first. Then, the dosage of paliperidone could be adjusted two weeks later according to clinical judgement. They will be followed and receive assessment of pharmacokinetics, metabolic parameters ( lipid profiles, glucose, insulin, adiponectin, leptin, and prolactin, etc.), and the treatment response.

Inclusion Criteria:

• diagnosis of schizophrenia or schizoaffective disorder according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)
• a minimal baseline total score of 60 on the PANSS
• those who had not received long-acting antipsychotic injection for the preceding 6 months
• physically healthy and standard clinical laboratory test results within laboratory reference ranges, or if outside the ranges, judged to be clinically insignificant by the investigators.

Exclusion Criteria:

• diagnosis of substance (including alcohol) dependence in the previous 6 months
• a medical condition that could affect absorption, metabolism, or excretion of the study drug
• substantial risk of suicide or violent behavior
• pregnancy or breastfeeding
• documented organic disease of the central nervous system
• unstable or critical untreated medical illness
• history of clozapine treatment in the previous 3 months
• participation in an investigational drug trial in the 30 days before screening.