ATYPICAL NEUROLEPTICS, PHARMACOLOGY AND C LINICAL RELEVANCE

Since the development of clozapine the investigation of atypical neuro leptic compounds has become increasingly relevant. Compared with class ic neuroleptics they are distinguished by either fewer or absent (cloz apine) extrapyramidal side effects, some of them also by lower increas es of serum prolactin concentrations. Pharmacologically they are a gro up of heterogeneous substances. At the level of transmitter systems a high 5HT2/D2-ratio is regarded as the best criterion to distinguish be tween atypical and classic neuroleptics. Further differences involve: the preferred effects of atypical neuroleptics on mesolimbic D2 recept ors compared to striatal dopaminergic neurotransmission; a higher pote ncy of some atypical neuroleptics to antagonize D1-receptors; the incr ease of serum corticosterone concentrations by some of the atypical ne uroleptics. The possible effects of atypical neuroleptics and their cl inical relevance are discussed.