Endocrine Abstracts

Current treatment for acromegaly includes dopamine agonists (DA), somatostatin receptor ligands (SRL) and GH receptor antagonists (GHRA). DA in monotherapy, is less than 10% effective achieving control of the disease, and its efficacy in addition to ongoing SRL is less studied, without obvious determining factors of response. We report 2 operated patients with incomplete response to SRL and to whom Cabergoline addition led to disease control.

Case 1: A man 36 years old was transesphenoidally operated of an intrasellar GH producing macroadenoma. Basal GH and after glucose (OGTT; GHOGTT) was 16.1 and 16.2 ng/ml, and IGFI 907 ng/ml (N <284). Four months after surgery GHOGTT was 5.4 ng/ml and IGFI 708 ng/ml. Treatment with Octreotide, 20 mg every 4 weeks, reduced GHOGTT 2.81 and IGFI to 470. Addition of Cabergoline began with 1 mg leading to 1.5 mg per week, obtaining reduction of IGFI under upper limit for age, with nadir of 113 ng/ml and basal GH of 0.2 ng/ml.

Case 2: A man 57 years old with long term acromegaly presented GHOGTT of 48 ng/ml, IGFI of 846 ng/ml, and normal prolactin. MRI showed a macroadenoma with right cavernous invasion. After surgery GHOGTT reduced to 5.15 and IGFI to 506. Treatment with Somatuline Autogel (120 mg monthly) got a GHOGTT of 1.11 and IGFI of 207. Addition of Cabergoline (up to 3 mg/week) reduced GHOGTT to 0.62 and IGFI to 140 with reduction in Somatuline to 90 mg/week. Employed drugs were well tolerated in both cases.

Combined treatment of SRL and DA resulted in control of the disease. Both reached most restrictive criteria of control (GHOGTT < 1 ng/ml and levels of IGFI under upper limits for age). One case could benefit lower dose of SRL.

The association of Cabergoline and SRL deserves a relevant role in the acromegaly treatment. It might be tried sistematically before the expensive use of Pegvisomant.