The mechanism of action of second-generation neuroleptics (risperidone)
Neuroleptic, or antipsychotic, agents are a group of drugs used to treat schizophrenia and other types of psychoses. Risperidone is a newer ‘atypical’, or ‘second-generation’, neuroleptic and is more selective than the older ‘typical’ neuroleptics. Risperidone can bind to dopamine D2, 5-HT2 and α2 adrenergic receptors in the brain. The efficacy of neuroleptics is thought to be due to antagonism of dopamine receptors in the mesolimbic and mesofrontal systems. The atypical neuroleptics, which have little or no affinity for D1 receptors, do not exhibit some of the side effects associated with D1 antagonism that the older neuroleptics have. The adverse effects associated with atypical neuroleptics, such as tachycardia, impotence and dizziness, are due to the non selective binding to α adrenoreceptors.
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References
Antipsychotic agents and lithium. In: Basic and clinical pharmacology, 8th edition. Katzung BG. USA: The McGraw Hill Companies, Inc, 2001:478–497.
Canadian Society of Hospital Pharmacists. Atypical antipsychotics. Raymond C. http://www.cshp-bc.com/events/speaker%20handouts/Colette%20Raymond%20AGM%202002.pdf. Accessed on 31 January 2003.