Neuroleptic-induced dopamine hyposensitivity.

In contrast to dopaminergic hypersensitivity induced by most neuroleptic drugs including fluphenazine, thioridazine induced hyposensitivity to subsequent apomorphine stereotypy in rats. The difference between thioridazine and fluphenazine may relate in part to anticholinergic properties of thioridazine, but appears to involve additional mechanisms. Differences in dopaminergic sensitization may be important to the management and prevention of tardive dyskinesia an iatrogenic disorder associated with chronic exposure to neuroleptics.