NEUROLEPTIC BINDING TO SIGMA-RECEPTORS - POSSIBLE INVOLVEMENT IN NEUROLEPTIC-INDUCED ACUTE DYSTONIA

Several antipsychotic drugs, belonging to various chemical classes, we re compared for their affinity for the sigma, dopamine-D-2, and muscar inic receptors. Many neuroleptic drugs were found to bind with high af finity to sigma(2) receptors, and the binding affinity was clearly dif ferent from that observed for dopamine-D-2 receptors. The dopaminergic and muscarinic theories for the physiopathology of acute dystonia are not completely satisfactory. Since the sigma receptors were reported to play a role in the control of movement, the high affinity of some n euroleptics for these sites suggests their possible involvement in som e side effects, such as drug-induced dystonia. There was a correlation between the clinical incidence of neutroleptic-induced acute dystonia and binding affinity of drugs for the sigma receptor might be involve d in neuroleptic-induced acute dystonia, but this might be partially c orrected by the intrinsic anticholinergic properties of the drug. (C) 1997 Society of Biological Psychiatry.