Therapy
The normalization of plasma prolactin levels must be proposed. In some cases this objective can be easily achieved, for example in hypothyroidism, with an appropriate substitution treatment with thyroid hormones and, in the forms of hyperprolactinemia due to the use of drugs, interrupting their administration.
On the other hand, the therapeutic problem appears to be more complex in the microadenoma forms and in the so-called "idiopathic" forms which, however, in most cases are caused by microadenomas whose existence cannot be demonstrated with the current diagnostic means.
There is still no agreement on the need to negotiate, since many studies show that their long-term evolution is towards stabilization and not towards growth. It is however advisable to lower the hormone levels if hyperprolactinemia is associated with a series of disorders of reproductive function (menstrual irregularities, missed ovulation, etc.), of sexual life (frigidity, pain felt during sexual activity) and of mineralization bone (osteoporosis). In these cases the therapy can be medical, surgical or radiotherapeutic.
Medical therapy represents the first choice both in the forms of hyperprolactinemia from pituitary micro and macroadenomas, and in idiopathic forms. Medical therapy uses a series of drugs with a stimulating action on the receptors that are activated by dopamine (a brain hormone). The most widely used hypoprolactinemizing drugs are:
cabergoline (trade name Dostinex) and bromocriptine (Parlodel). Others are lisuride, lergotrile, pergolide, metergoline and dihydroergocriptine.
The drugs determine a rapid reduction of prolactin values and consequent remission of clinical symptoms in 95% of cases. They also lead to a reduction in the volume of macroadenomas in 60-70% of cases and to the complete disappearance of the lesion in 10-15% of cases of microadenoma. The wide choice of these dopaminergic drugs allows to overcome intolerance phenomena that can occur with one drug replacing it with another.
Carbegoline and bromocriptine inhibit the synthesis and release of prolactin by acting both at the hypothalamic and pituitary level. Furthermore they are able to reduce the size of the prolactin-secreting pituitary adenomas. Carbegoline has a very long duration of action, so a single dose a week is sufficient. Bromocriptine, on the other hand, must be administered several times during the same day. The side effects of carbegoline are also considerably lower than those of bromocriptine. When present, they manifest themselves from the first administration and consist of a drop in blood pressure, especially during standing, nausea and vomiting, neuropsychiatric disorders, sometimes hallucinations. To minimize the possibility of getting these effects, you need to start treatment with Dostinex in reduced doses: half a 0.5 milligram tablet every week for two weeks until you reach the dosage of 1-2 milligrams per week.
Treatment suspension is usually followed by resumption of tumor growth, so therapy must be continued indefinitely.
In some cases of physiological hyperprolactinemia (not due to pituitary adenomas), especially stress and sleep disorders, in women who do not wish to become pregnant, it is preferable to administer an estrogen-progestin contraceptive pill to regularize the menstrual cycle, since its side effects are usually lower than those given by the dopaminergic drugs described above.
Surgical therapy consists of the surgical removal of prolactin-secreting pituitary adenomas. It is carried out via the transphenoid and an endoscope is used (a small flexible tube equipped with a camera at its peak) which is introduced into one of the patient's two nostrils, previously anesthetized. The camera is connected to a digital video system. The endoscope must reach the spheroidal direction, and from there to the sella turcica, where the adenoma will be identified and removed. The indication to surgery should be placed only in case of intolerance or more or less total resistance to medical treatment, which occurs in one third of cases of microadenomas.
Radiation therapy today has a completely secondary role and exceptional indications. Its use is limited to the treatment of surgery failures.
Monitoring of pituitary adenomas
Patients with microadenoma, given the slow growth of the tumor, should be checked once a year with measurement of plasma prolactin levels and with a CT scan of the sella turcica; in the absence of growth, CT can be performed every 2-3 years. More sophisticated and more frequent controls are instead necessary in the presence of an increase in prolactin levels, the appearance of headache or visual disturbances, or changes in CT. Patients with macroadenoma require closer, annual or, better yet, semi-annual surveillance, combining the above tests with an MRI or magnetic resonance tomography (TRM).
