What is the best initial treatment for a hyperprolactinaemia diagnosed in a 42-year-old woman?

The best initial treatment for hyperprolactinaemia, particularly in a 42-year-old woman, is the use of a dopamine agonist, specifically cabergoline. This medication effectively works by directly stimulating dopamine receptors, which in turn inhibits prolactin secretion from the pituitary gland. In cases of prolactinoma, which is the most common cause of elevated prolactin levels, cabergoline is highly effective at reducing tumor size and alleviating symptoms associated with hyperprolactinaemia, such as galactorrhea and menstrual irregularities.

Dopamine agonists are preferred as the first-line therapy because they are non-invasive and have a high success rate. Cabergoline has a favorable side effect profile compared to other treatment options and can be administered less frequently due to its long half-life.

Other treatment modalities such as radiotherapy and transsphenoidal surgery are typically reserved for cases where medical management fails, or in scenarios where there is significant compressive symptoms or concern about malignancy. Octreotide, while useful in conditions of acromegaly and certain neuroendocrine tumors, is not effective in treating hyperprolactinaemia since it acts on different hormonal pathways unrelated to prolactin regulation