4. Endocrine and metabolic effects—

Endocrine and metabolic effects include hyperprolactinemia, gynecomastia, the amenorrhea-galactorrhea syndrome, and infertility. Most of these adverse effects are predictable manifestations of dopamine D2 receptor blockade in the pituitary; dopamine is the normal inhibitory regulator of prolactin secretion. Elevated prolactin is prominent with risperidone. Significant weight gain and hyperglycemia due to a diabetogenic action occur with several of the atypical agents, especially clozapine and olanzapine. These effects may be especially problematic in pregnancy. Aripiprazole and ziprasidone have little or no tendency to cause hyperglycemia, hyperprolactinemia, or weight gain.