Rapid and long-lasting suppression of prolactin secretion and shrinkage of prolactinomas after injection of long-acting repeatable form of bromocriptine (Parlodel LAR).

Five patients with PRL-secreting macroadenoma and nine patients with PRL-secreting microadenoma or idiopathic hyperprolactinaemia were treated with monthly administrations of long-acting bromocriptine suitable for repeatable injections (Parlodel LAR) for 1-12 cycles of treatment. A significant shrinkage of tumour mass and the recovery of visual field defects were observed in patients with macroprolactinoma. Plasma PRL levels decreased to 16.8 and 18.1% of pretreatment values, in macroprolactinoma and idiopathic or microadenomatous hyperprolactinaemic subjects, respectively, during the first cycle of treatment, reaching the normal range in three patients of each group. During the following cycles of treatment, two patients with macroprolactinoma and one patient with idiopathic or microadenomatous hyperprolactinaemia became normoprolactinaemic. Adverse reactions generally did not last beyond the first days of administration and decreased with the progression of the treatment. In conclusion, its effectiveness and the fact that it is well tolerated, may suggest that this form of bromocriptine may be used as a first therapeutic approach for patients with PRL-secreting adenomas, particularly when shrinkage of a macroadenoma is urgently required.