Dopamine D2/3 receptor occupancy by quetiapine in striatal and extrastriatal areas

Quetiapine is next to clozapine an antipsychotic agent that exerts hardly any extrapyramidal side-effects at clinical efficacious doses. Some previous receptor occupancy studies reported preferential extrastriatal D2/3 receptor (D2/3R)-binding properties of second-generation antipsychotics and suggested this as possible reason for improved tolerability. This positron emission tomography (PET) investigation was designed to compare the occupancy of dopamine D2/3Rs by quetiapine in striatal and extrastriatal brain regions. Therefore, a cohort of 16 quetiapine-treated psychotic patients underwent an [18F]fallypride (FP) PET scan. Due to the high affinity of FP and its comparatively long half-li…