title: Striatal dopamine D2 receptor binding of risperidone in schizophrenic patients as assessed by 123I-iodobenzamide SPECT: a comparative study with olanzapine.
abstract: The aim of this investigation was to compare the degree of striatal dopamine-(D2) receptor blockade by two atypical antipsychotic drugs, risperidone and olanzapine. The percentage of D2 receptor occupancy during treatment was calculated by comparing the results of 123I-iodobenzamide SPECT with those from healthy control subjects. Twenty inpatients suffering from schizophrenia or schizoaffective psychosis according to DSM IV/ICD-10 criteria were treated with clinically recommended doses of risperidone and compared with 13 inpatients treated with up to 20 mg olanzapine. Neuroleptic dose and D2 receptor blockade correlated strongly for both risperidone (Pearson r = -0.86, p = 0.0001) and olanzapine (Pearson r = -0.77, p = 0.002). There was no significant difference between the D2 receptor occupancy of the two substances when given in the clinically recommended dose range (unpaired t-test, t = -0.112, p = 0.911).
authors.affiliation: Department of Psychiatry, Ludwig-Maximilians-University Munich, Germany.
authors.forename: G J E
authors.initials: GJ
authors.lastname: Schmitt
authors.forename: E M
authors.initials: EM
authors.lastname: Meisenzahl
authors.forename: S
authors.initials: S
authors.lastname: Dresel
authors.forename: K
authors.initials: K
authors.lastname: Tatsch
authors.forename: B
authors.initials: B
authors.lastname: Rossmüller
authors.forename: T
authors.initials: T
authors.lastname: Frodl
authors.forename: U W
authors.initials: UW
authors.lastname: Preuss
authors.forename: K
authors.initials: K
authors.lastname: Hahn
authors.forename: H J
authors.initials: HJ
authors.lastname: Möller
mesh_terms: D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000378:metabolism* / Q000627:therapeutic use; D001549:Benzamides; D001569:Benzodiazepines; D003287:Contrast Media; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D065127:Dopamine D2 Receptor Antagonists; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D010890:Pirenzepine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000493:pharmacokinetics*; D011618:Psychotic Disorders / Q000000981:diagnostic imaging / Q000188:drug therapy*; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D018967:Risperidone / Q000493:pharmacokinetics* / Q000627:therapeutic use; D012559:Schizophrenia / Q000000981:diagnostic imaging / Q000188:drug therapy*; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D014150:Antipsychotic Agents; D001549:Benzamides; D003287:Contrast Media; D065127:Dopamine D2 Receptor Antagonists; D007457:Iodine Radioisotopes; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; D001569:Benzodiazepines; D010890:Pirenzepine; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide; D018967:Risperidone; D000077152:Olanzapine