Atypical antipsychotic drugs dopamine receptor affinities

Clozapine (Clozaril), a 5-HT2A/2c-receptor antagonist, represents a class of atypical antipsychotic drugs with reduced incidence of extrapyramidal side effects compared to the classical neuroleptics, and possibly a greater efficacy for reducing negative symptoms of schizophrenia. Clozapine also has a high affinity for subtypes of dopamine receptors. 

No recognised classification system exists for atypical antipsychotics.Tentative terms based on receptor binding profiles have been applied to certain drug groupings.for example broad spectrum atypicals for clozapine, olanzapine and quetiapine. whilst risperidone and ziprasidone have been described as high affinity serotonin-dopamine antagonists . 

Atypical antipsychotic low affinity for dopamine receptors, higher for and S-HTja receptors less EPS adverse effects than other antipsychotic drugs. Tox ANS effects, agranulocytosis (infrequent but significant). 

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