title: Dose relationship of limbic-cortical D2-dopamine receptor occupancy with risperidone.
abstract: BACKGROUND
  It has been suggested that the antipsychotic effect of antipsychotics is mediated by the antagonism of the dopamine D2 receptor in the limbic-cortical regions. Risperidone has an atypical property, but its effect on limbic-cortical regions has not been evaluated.
  
  
  OBJECTIVE
  In this study, we examined the relationship among doses of risperidone and limbic-cortical dopamine D2 receptor occupancy using positron emission tomography.
  
  
  METHODS
  Seven patients with schizophrenia were scanned during the steady state with risperidone. Their occupancies in limbic-cortical regions were determined using positron emission tomography with [11C]FLB 457.
  
  
  RESULTS
  The average occupancy ranged from 38% to 80% on doses of 1-6 mg/day. The saturation curve plotted against the drug level fit the data well.
  
  
  CONCLUSIONS
  Our results demonstrate that the D2 receptor occupancy with risperidone in the limbic-cortical regions seems to be similar to that of previous reports regarding the striatum, and it would be comparable to that of typical antipsychotics.
authors: National Institute of Radiological Sciences, Chiba-shi, Japan. suhara@nirs.go.jp
authors: F
authors: F
authors: Yasuno
authors: T
authors: T
authors: Suhara
authors: Y
authors: Y
authors: Okubo
authors: Y
authors: Y
authors: Sudo
authors: M
authors: M
authors: Inoue
authors: T
authors: T
authors: Ichimiya
authors: S
authors: S
authors: Tanada
mesh_terms: D000328:Adult; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism*; D018492:Dopamine Antagonists / Q000097:blood / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008032:Limbic System / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D017448:Receptors, Dopamine D2 / Q000187:drug effects*; D018967:Risperidone / Q000097:blood / Q000494:pharmacology*; D012559:Schizophrenia / Q000378:metabolism; D014055:Tomography, Emission-Computed
chemical_list: D018492:Dopamine Antagonists; D017448:Receptors, Dopamine D2; D018967:Risperidone