Odapipam (NNC 756) is a selective, high affinity and benzazepine dopamine D₁ receptor antagonist with a K_d of 0.18 nM. Odapipam is also a superior positron emission tomography (PET) radiotracer^[1][2]. IC50 & Target: Dopamine D₁ receptor^[1] In Vivo: The metabolism of Odapipam has been studied with phenobarbital-induced rat liver microsomes. During the incubation of Odapipam, five different metabolites are formed. The electron-ionization (EI⁺) mass spectra of the metabolites indicated the formation of N-desmethyl-Odapipam, 1-hydroxy-Odapipam, the two isomers of 3′-hydroxy-Odapipam and a metabolite which is dehydrogenated in the dihydrobenzofuran moiety^[3].