[The biochemical effect profile of zotepine in comparison with other neuroleptics]

The clinical action of a neuroleptic depends on its biochemical and pharmacological profile which is related to pharmacokinetic and pharmacodynamic properties. All neuroleptics influence not only the various dopaminergic systems but also more or less markedly the alpha-adrenergic, acetylcholine, histamin, serotonin and GABA systems. In this regard we can describe zotepine (a tricyclic neuroleptic from the group of the dibenzothiepines, with a central seven-membered ring) as follows: It is to some extent comparable with chlorpromazin in respect of its antidopaminergic activity, but zotepine exercises a more marked blocking action on the D1 receptors than the classical neuroleptics. 5-HT1 and 5-HT2 receptors are also among the receptors that are most markedly blocked by zotepine. The action on the noradrenergic system is more pronounced than that of chlorpromazin, thioridazin or haloperidol. It exercises a merely medium-grade action on the cholinergic system. This receptor blocking profile could explain the rare occurrence or the mild manifestation of extrapyramidal motor disturbances in the clinical use of zotepine.