title: Fluctuating plasma levels of the active moiety of risperidone is related to occurrence of extrapyramidal symptoms.
abstract: In the present study, we compared the plasma levels of the active moiety (i.e. risperidone plus 9-hydroxyrisperidone) in a steady state in 54 Japanese schizophrenic patients with or without emerging extrapyramidal symptoms (EPS and non-EPS groups, respectively) who were treated with 4 mg/day risperidone. No differences were observed in the plasma levels of the active moiety at 4 and 8 weeks after risperiodne administration in both groups. However, the EPS group patients showed a greater number of fluctuations/larger fluctuations in the plasma active moiety levels than those in the non-EPS group. These results suggest that a stable plasma active moiety level maybe important for preventing EPSs during treatment with risperidone.
authors.affiliation: Department of Psychiatry, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan.
authors.forename: Reiji
authors.initials: R
authors.lastname: Yoshimura
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Ueda
authors.forename: Atsuko
authors.initials: A
authors.lastname: Ikenouch-Sugita
authors.forename: Wakako
authors.initials: W
authors.lastname: Umene-Nakano
authors.forename: Hikaru
authors.initials: H
authors.lastname: Hori
authors.forename: Shingo
authors.initials: S
authors.lastname: Kakihara
authors.forename: Jun
authors.initials: J
authors.lastname: Nakamura
keywords: 9-hydroxyrisperidone; Risperidone; adherence; extrapyramidal symptoms; schizophrenia