A 29-year-old woman presents with 6 months of irregular menses and bilateral milky nipple discharge. She takes risperidone for schizophrenia. Vital signs: BP 118/76, HR 82, RR 16, Temp 37°C. Pregnancy test is negative. Serum prolactin is elevated at 68 ng/mL (normal <25). Visual field examination shows no deficits. MRI brain shows no sellar mass. Which of the following mechanisms best explains this patient's endocrine abnormality?
- A)Destruction of adrenal zona fasciculata
- B)Increased hypothalamic GnRH secretion
- C)Autoimmune destruction of thyroid follicular cells
- D)Increased posterior pituitary oxytocin release
- E)Decreased hypothalamic dopamine effect on lactotrophsGABARITO
Explicação
Risperidone blocks dopamine receptors. Dopamine normally tonically inhibits prolactin release from anterior pituitary lactotrophs, so reduced dopamine effect causes hyperprolactinemia with galactorrhea and menstrual irregularity. The negative pregnancy test an... Ver explicação completa e trilha adaptativa →