Therapeutic Occupancy of the D2/3-preferring Dopamine Receptor Agonist Pramipexol Parkinson's Disease ([18F]-fallypride PET study)

It was the aim of the study to measure the occupancy of dopamine D2/3 receptors using the D2/3 receptor antagonist [18F]-fallypride (FP) and PET in patients with Parkinson's disease (PD) on and off medication with the D3-preferring agonist pramipexol. The therapeutic occupancy of brain dopamine receptors by various neuroleptics has been repeatedly investigated using [11C]-raclopride PET and [123I]-IBZM SPECT competition paradigms in schizophrenia. It was generally shown that therapeutic response is obtained with blockade of 60–80% of striatal D2/3 receptors with lower D2/3 occupancy during treatment with clozapi…