BACKGROUND: Selective action at limbic cortical dopamine D(2)-like receptors could mediate atypical antipsychotic efficacy with few extrapyramidal side-effects. AIMS: To test the hypothesis that quetiapine has 'limbic selective' D(2)/D(3) receptor occupancy in vivo. METHOD: The high-affinity D(2)/D(3) ligand [(123)I]-epidepride and single photon emission tomography were used to estimate D(2)/D(3) specific binding and an index of relative percentage D(2)/D(3) occupancy in striatal and temporal cortical regions for quetiapine-treated patients (n=6). Quetiapine-, and previously studied typical-antipsychotic- and clozapine-treated patients were compared. RESULTS: Mean (s.d.) relative percentage D(2)/D(3) receptor occupancy by quetiapine was 32.0% (14.6) in striatum and 60.1% (17.2) in temporal cortex (mean daily dose 450 mg: range 300-700 mg/day). Quetiapine treatment resulted in limbic selective D(2)/D(3) blockade similar to clozapine and significantly higher than typical antipsychotics. CONCLUSIONS: Preliminary data suggest that limbic selective D(2)/D(3) receptor blockade is important for atypical drug action.
BACKGROUND: Selective action at limbic cortical dopamine D(2)-like receptors could mediate atypical antipsychotic efficacy with few extrapyramidal side-effects. AIMS: To test the hypothesis that quetiapine has 'limbic selective' D(2)/D(3) receptor occupancy in vivo. METHOD: The high-affinity D(2)/D(3) ligand [(123)I]-epidepride and single photon emission tomography were used to estimate D(2)/D(3) specific binding and an index of relative percentage D(2)/D(3) occupancy in striatal and temporal cortical regions for quetiapine-treated patients (n=6). Quetiapine-, and previously studied typical-antipsychotic- and clozapine-treated patients were compared. RESULTS: Mean (s.d.) relative percentage D(2)/D(3) receptor occupancy by quetiapine was 32.0% (14.6) in striatum and 60.1% (17.2) in temporal cortex (mean daily dose 450 mg: range 300-700 mg/day). Quetiapine treatment resulted in limbic selective D(2)/D(3) blockade similar to clozapine and significantly higher than typical antipsychotics. CONCLUSIONS: Preliminary data suggest that limbic selective D(2)/D(3) receptor blockade is important for atypical drug action.
Authors: James M Stone; Rodrigo A Bressan; Kjell Erlandsson; Peter J Ell; Lyn S Pilowsky Journal: Psychopharmacology (Berl) Date: 2005-09-14 Impact factor: 4.530
Authors: Erik Ryding; Mats Lindström; Björn Brådvik; Martin Grabowski; Peter Bosson; Lil Träskman-Bendz; Ingmar Rosén Journal: Eur J Nucl Med Mol Imaging Date: 2004-03-11 Impact factor: 9.236
Authors: Robert M Kessler; Neil D Woodward; Patrizia Riccardi; Rui Li; M Sib Ansari; Sharlett Anderson; Benoit Dawant; David Zald; Herbert Y Meltzer Journal: Biol Psychiatry Date: 2009-02-28 Impact factor: 13.382