Other receptor mechanism

Most of the newer atypical antipsychotic agents have higher affinities for other receptors than for the D2 receptor. For example, α adrenoceptor-blocking action correlates well with antipsychotic effect for many of the drugs. The receptor-binding characteristics of the newer antipsychotic drugs have led to a serotonin hypothesis as an alternative to the dopamine hypothesis of the nature of schizophrenia. Most of the atypical drugs cause less extrapyramidal dysfunction than standard drugs. With the exception of haloperidol, all antipsychotic drugs block H1 receptors to some degree.