Effectiveness of a single injectable dose of bromocriptine long acting in the treatment of macroprolactinomas

The aim of the present study was to investigate the effect of a new galenic injectable form of bromocriptine (Parlodel LA), characterized by sustained release of bromocriptine for 4-6 weeks, in 3 patients with prolactin-secreting macroadenomas through a 42-day follow-up. The following parameters were considered: decrease of plasma prolactin levels, reduction of tumor size studied by seriate CT scan controls and recovery of eventual visual fields impairments. Parlodel LA induced a sharp decrease of plasma prolactin levels for at least 42 days, without reaching normal values. This treatment also caused a rapid and marked shrinkage of tumors in all patients. Moreover, in two patients with constriction of visual fields a clear and progressive improvement in one and only a slight amelioration in the other were observed. There were almost no side effects except for mild nausea in one patient and transient orthostatic in another. These results demonstrate that Parlodel LA produces a long-lasting reduction of plasma prolactin levels and a rapid shrinkage of the tumor with almost no side effects.