Risperidone chemical structure

Recently a number of novel, non-classical chemical structures, referred to as atypical neuroleptics, have been described clozapine (4.93), risperidone (4.94), olanzapine (4.95), and sertindole (4.96). These atypical neuroleptics have two distinguishing... 

This agent has a different chemical structure (Fig. 11—38) and a considerably simpler pharmacologic profile than clozapine (Fig. 11—39). Risperidone is especially atypical at lower doses but can become more conventional at high doses in that EPS can occur if the dose is too high. Risperidone thus has favored uses, not only in schizophrenia at moderate doses but also for conditions in which low doses of conventional antipsychotics have been used in the past, for example, for elderly patients with... 

Quetiapine also has a chemical structure related to that of clozapine (Fig. 11—36), but it has several differentiating pharmacologic (Fig. 11—41) and clinical features, not only as compared with clozapine (Fig. 11—37) but also as compared with risperidone (Fig. 11-39) and olanzapine (Fig. 11-40). Quetiapine is very atypical in that it causes virtually no EPS at any dose and no prolactin elevations. Thus, quetiapine tends to be the preferred atypical antipsychotic for patients with Parkinson s disease and psychosis. It is also useful in schizophrenia, bipolar disorder, and other types of psychosis, in which it has few extrapyramidal side effects. 

Fig. 13.1 Chemical structure of clozapine, some of its structural analogues, typical (chlorpromazine, haloperidol) and atypical antipsychotics (risperidone, ziprasidone, sertindole and amisulpride) unrelated to clozapine.

Chart 1.10 Chemical structures of clozapine (23), risperidone (24), olanzapine (25), seroquel (26). 

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