Occupancy of brain serotonin transporters during treatment with paroxetine in patients with social phobia: a positron emission tomography study with 11C McN 5652.
BACKGROUND
Although selective serotonin reuptake inhibitors (SSRIs) are widely used in the treatment of anxiety and depressive disorders, the occupancy of the serotonin reuptake transporter (SERT) achieved in humans at typical clinical doses by these agents remains poorly characterized.


OBJECTIVE
The purpose of this study was to determine the occupancy of the SERT achieved in vivo by the SSRI paroxetine in social phobia patients at typical antianxiety doses.


METHODS
Measures of SERT availability were obtained with positron emission tomography and the SERT radiotracer [(11)C](+)-McN 5652 in five patients with social phobia before and during treatment with paroxetine at usual therapeutic doses (20-40 mg per day).


RESULTS
Occupancy of the SERT by paroxetine was high in all subjects and in all regions measured after 3-6 months of continuous treatment.


CONCLUSIONS
The results of this study in an anxiety disorder sample are consistent with previously reported results in a depressed sample and suggest that paroxetine at therapeutic doses achieves very high occupancy levels of the SERT.
Kent
Justine M
JM
New York State Psychiatry Institute, New York, NY 10032, USA. JMK14@columbia.edu
Coplan
Jeremy D
JD
Lombardo
Ilise
I
Hwang
Dah-Ren
DR
Huang
Yiyun
Y
Mawlawi
Osama
O
Van Heertum
Ronald L
RL
Slifstein
Mark
M
Abi-Dargham
Anissa
A
Gorman
Jack M
JM
Laruelle
Marc
M
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects*; D001931:Brain Mapping; D002352:Carrier Proteins / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007546:Isoquinolines / Q000493:pharmacokinetics; D008279:Magnetic Resonance Imaging; D008297:Male; D008562:Membrane Glycoproteins / Q000187:drug effects* / Q000502:physiology; D026901:Membrane Transport Proteins; D008875:Middle Aged; D009419:Nerve Tissue Proteins; D017374:Paroxetine / Q000493:pharmacokinetics / Q000627:therapeutic use*; D010555:Personality Inventory; D010698:Phobic Disorders / Q000000981:diagnostic imaging / Q000188:drug therapy*; D050486:Serotonin Plasma Membrane Transport Proteins; D017367:Selective Serotonin Reuptake Inhibitors / Q000493:pharmacokinetics / Q000627:therapeutic use*; D014055:Tomography, Emission-Computed
D002352:Carrier Proteins; D007546:Isoquinolines; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D017374:Paroxetine; D050486:Serotonin Plasma Membrane Transport Proteins; D017367:Selective Serotonin Reuptake Inhibitors; C493230:SLC6A4 protein, human; C058079:McN 5652