Endocrine effects antipsychotic drugs

The first phenothiazine antipsychotic drugs, with chlorpromazine as the prototype, proved to have a wide variety of central nervous system, autonomic, and endocrine effects. Although efficacy of these drugs is primarily driven by D2-receptor blockade, their adverse actions were traced to blocking effects at a wide range of receptors including a adrenoceptors and muscarinic, Hi histaminic, and 5-HT2 receptors. 

Other side effects characteristic of most neuroleptic-antipsychotic drugs include autonomic effects such as postural hypotension and impaired sexual function. Increased plasma prolactin represents an endocrine effect. 

Hypothalamus and Endocrine Systems Endocrine changes occur because of effects of antipsychotic drugs on the hypothalamus or pituitary, including their antidopaminergic actions. Most older antipsychotics and risperidone increase prolactin secretion, probably due to a blockade of the pituitary actions of the tuberoinfundibular dopaminergic neurons. These neurons project from the arcuate nucleus of the hypothalamus to the median eminence, where they deliver DA to the anterior pituitary via the hypophyseoportal blood vessels. Dj receptors on lactotropes in the anterior pituitary mediate the tonic prolactin-inhibiting action of DA (see Chapter 55). 

Endocrine A raised prolactin concentration occurs not uncommonly as an adverse effect of antipsychotic drugs but is less often associated with antidepressants. In a comprehensive review of case reports and prospective and retrospective studies, it was documented that all antidepressant classes, except mirtazapine, have been reported to cause hyperprolactinemia [2 ]. However, the findings were mostly derived from case reports and were inconsistent for individual agents within each antidepressant class. 

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