Endocrine Abstracts

The aim of the study: To investigate the anti-proliferative effect of cabergoline (CAB) which was used in different regimes of suppressive therapy during 12 months in patients with prolactinoma (PROL).

Subjects and methods: It was examined and underwent a 12 month course of treatment by selective dopamine agonist CAB 61 patients with PROL: microadenoma 42, macro&giant PROL - 19. (52 women/9 men) aged 16–66 years. The total duration of the disease ranged from 1 to 60 months, average (12.3±10.1) months. PROL was verified using MRI 1.5T. Pituitary volume was calculated by the Di Chiro-Nelson. Were estimated total and partial secretory activity (PSA) in PROL. PRL blood levels (ng/ml) were determined. Applied two modes of therapy: 1 – the mode of gradual increase of a CAB dose, since 0.5 mg/week with the subsequent control of the PRL blood level in each 4 weeks and titration CAB dose if necessary (increase in a week dose by 0.25–0.5 mg); 2 – the mode of high starting doses from calculation: the quantity of tablets CAB (0.5 mg) corresponded to frequency rate of increase of the PRL blood level in relation to the upper limit of age norm, but no more than 4 mg (8 tablets) a week. The statistical data analysis was carried out with SPSS version 9.0.

Results: At purpose of high starting doses of CAB after 1 mth of treatment PRL level in 58.1% of patients decreased to the reference values, including in patients with macroPROL after 1 month at 26.3% of patients had achieved target levels, after 3 months - at 84.2%, and by 6 months of treatment - at 100% patients. In all patients it was a statistically significant decreasing the pituitary volume after 12 months of treatment (P <0,001), but only in patients who were treated high starting high dose CAB recorded decrease in the size of adenoma by 50% or more of the basal volume: at 9 microPROL and 4 macroPROL.

Conclusions: The most expressed anti-proliferative effect is noted at application of high starting doses of CAB. Optimum therapeutic average and cumulative doses of CAB for achievement of maximum therapeutic effect at patients with microPROL are doses of 0.8 mg/week and 33.8 mg/year, respectively; for patients with macro&giant PROL – 1.3 mg/week and 67.6 mg/year, respectively. At patients with microPROL the positive therapeutic effect is reached on a smaller cumulative CAB dose which is associated with a lower risk of complications in the long term period.