A comparison between intensive and conventional cabergoline treatment of newly diagnosed patients with macroprolactinoma

Abstract

Context: Intensive treatment with cabergoline may lead to earlier reduction in prolactin and tumour volume in comparison to conventional schedule.

Objective: To compare the efficacy and safety of two different dosing schedules of cabergoline in patients with macroprolactinoma.

Design: Prospective, randomized trial in drug naive patients assigned to conventional (4 weekly escalation by 0·5 mg per week, group A) or intensive (weekly increase by 1 mg per week followed by 4 weekly escalation, group B) treatment with cabergoline.

Outcome measure: The duration required to achieve normoprolactinemia and tumour shrinkage of >50% as a composite end-point.

Results: 38 patients (19 in each group) completed the study with a mean follow-up of 64·3 ± 24·9 weeks. More subjects (22%) achieved the composite end-point in group B (18/19) as compared to the group A (14/19) (P = 0·18). The duration of cabergoline treatment required to achieve the composite end-point was 13·1 ± 9·5 weeks vs 19·3 ± 15·7 weeks (P = 0·34) in the group A and B, respectively. A reduction in prolactin of ≥90% by the fourth week of cabergoline therapy predicted subsequent normalization of prolactin (AUC 0·78; P = 0·04). A further increase in cabergoline dosage after normalization of prolactin in patients with tumour reduction of <50%, led to further tumour shrinkage by 31·2% in an additional 26·3% of patients.

Conclusions: Intensive treatment with cabergoline is not superior to the conventional recommended dosage schedule in respect to the time necessary to achieve normoprolactinemia and ≥50% tumour shrinkage.

Clinical trial registry: NCT 01143584.

Trial registration: ClinicalTrials.gov NCT01143584.