title: Striatal D(2) receptor occupancy in bipolar patients treated with olanzapine.
abstract: We explored the relationship between striatal dopamine-2 (D(2)) receptor occupancy and extra-pyramidal symptoms (EPS) in bipolar patients receiving olanzapine. Seventeen patients with a DSM-IV diagnosis of bipolar disorder were treated with 5-45 mg/day olanzapine for at least 14 days. After that period, D(2) receptor occupancy was determined using Iodobenzamide (IBZM) and SPECT. EPS were assessed by the Simpson-Angus Scale (SAS) and Barnes-Akathisia Scale (BAS). We found a dose-dependent increase in occupancy: 5 mg led to 28-50%, 10 mg to 40-68%, 15 mg to 69%, 20 mg to 57-66%, 30 mg to 66% and 45 mg to 80% D(2) receptor occupancy; and a significant correlation between plasma levels and occupancy (R(2)=.55, P=.001). Similar to schizophrenic patients, bipolar patients did not exhibit EPS at D(2) occupancy levels of 28 to 80%. Although we did not find an increased vulnerability for acute EPS in bipolar patients receiving olanzapine at clinical relevant doses, this needs to be replicated with larger sample sizes.
authors.affiliation: Department of General Psychiatry, Medical University Vienna, Vienna, Austria.
authors.forename: Trawat
authors.initials: T
authors.lastname: Attarbaschi
authors.forename: Julia
authors.initials: J
authors.lastname: Sacher
authors.forename: Thomas
authors.initials: T
authors.lastname: Geiss-Granadia
authors.forename: Nikolas
authors.initials: N
authors.lastname: Klein
authors.forename: Nilufar
authors.initials: N
authors.lastname: Mossaheb
authors.forename: Rupert
authors.initials: R
authors.lastname: Lanzenberger
authors.forename: Susanne
authors.initials: S
authors.lastname: Asenbaum
authors.forename: Robert
authors.initials: R
authors.lastname: Dudczak
authors.forename: Siegfried
authors.initials: S
authors.lastname: Kasper
authors.forename: Johannes
authors.initials: J
authors.lastname: Tauscher
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001569:Benzodiazepines / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D049268:Positron-Emission Tomography / Q000379:methods; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D017367:Selective Serotonin Reuptake Inhibitors / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use*; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
chemical_list: D001569:Benzodiazepines; D000077152:Olanzapine; D017448:Receptors, Dopamine D2; D017367:Selective Serotonin Reuptake Inhibitors