[Atypical neuroleptics. Review of the available clinical data]

Pharmacological treatment of schizophrenia in based in the hypothesis that disturbances in central dopaminergic (DA) systems, i.e. increased DA-activity in the mesolimbic system, are involved in the pathogenesis of these psychotic disorders. Since neuroleptics exert a broad spectrum of pharmacological activities, during the last decade efforts have been undertaken to develop new antipsychotics, separating their antipsychotic action from their extrapyramidal (EPS) effects. Neuroleptics with this kind of properties have been designated atypical, although being a rather heterogenous group. In fact, some of the atypical antipsychotics are selective with respect to neurotransmitter system or regional brain activity like the benzamides, while others are non-selective at all such as the dibenzodiazepine derivate clozapine, and interfere with different receptor systems. In general, the atypical antipsychotics can be divided among two groups: DA-selective compounds and receptor non-specific agents. Of the DA-selective compounds, the group of the benzamides form a distinct chemical class, of which sulpiride has been the most thoroughly investigated, followed by remoxipride. Concerning the antipsychotic effects of the benzamides, sulpiride as well as remoxipride have been demonstrated to be equipotent as compared to classical neuroleptics like chlorpromazine and haloperidol, without however inducing either EPS or anticholinergic symptoms of importance. With respect to the dibenzodiazepine derivate clozapine, it has been demonstrated that this compound has not only potent antipsychotic properties but, more important, may be effective in severely ill treatment resistant patients, without most probably the risk of inducing EPS. Finally, the series of compounds, characterized by serotonin -S2- and dopamine -D2- antagonistic properties may be of importance, albeit they do not meet the presently common definition of atypicality.(ABSTRACT TRUNCATED AT 250 WORDS)