Dopamine D1 receptor antagonism in schizophrenia: is there reduced risk of extrapyramidal side-effects?

The first selective D1 dopamine receptor antagonist, SCH23390, has been reported to be active in preclinical tests that predict antipsychotic activity in schizophrenic patients. This is particularly exciting because it has been claimed that this compound is 'atypical', in that it has a reduced propensity to induce extrapyramidal side-effects. However, in considering the evidence from preclinical screening tests for antipsychotic activity and extrapyramidal side-effects of potential neuroleptic drugs, Jarmo Hietala and colleagues conclude that the majority of available data is not compatible with the postulated atypical profile of SCH23390.