Relationship of neuroleptic drug effects at brain dopamine, serotonin, alpha-adrenergic, and histamine receptors to clinical potency

The authors examined the potencies of 22 neuroleptic drugs competing for binding sites associated with dopamine, serotonin, alpha- adrenergic, and histamine receptors in brain membranes. They found that although many neuroleptics are quite potent in competing at several of these receptor sites, the average antipsychotic clinical potency correlates closely only with the drug affinity for dopamine receptors labeled by 3H-spiroperidol At clinically effective doses, however, substantial occupancy of serotonin, alpha-adrenergic, and histamine receptors often occurs and may account for some of the auxiliary actions of neuroleptics.