Clozapine and D1/D2 Antagonism in Extrapyramidal Functions

Abstract

One of the main advantages of clozapine is that it rarely produces extrapyramidal syndromes and tardive dyskinesia. This advantage is linked to the atypical biochemical profile of clozapine, especially its combined and low blockade of D₁ and D₂ receptors. The level of D₂ receptor blockade is too low to induce extrapyramidal side-effects, and D₁ antagonists have a lower extrapyramidal side-effect potential than traditional D₂ neuroleptics, especially with respect to dystonia. The combined and balanced D₁/D₂ receptor blockade may prevent the development of a dysbalance between D₁/D₂ receptor function (in favour of D₁) which otherwise might lead to tardive dyskinesia.