Role of the addition of cabergoline to the management of acromegalic patients resistant to longterm treatment with octreotide LAR

The aim of this prospective open trial was to evaluate the efficacy in normalizing IGF-I levels of the addition of cabergoline to the treatment of acromegalic patients partially responsive to Octreotide-LAR (OCT-LAR), a long acting somatotastin analog (SSA). Fifty-two patients who did not achieve hormonal control after longterm therapy (at least, 12 months) with OCT-LAR (30 mg every 28 days intramuscularly) were given cabergoline in addition to the SSA treatment. Normalization of IGF-I levels was achieved in 40.4% of patients by 6 months after the addition of cabergoline (1.0–3.0 mg/week; mean, 2.19 ± 0.64), and these patients were considered responsive. Compared to non-responsive subjects, responsive patients had significantly lower mean %ULNR-IGF-I and GH levels. However, the rate of hyperprolactinemia and positive immunohistochemical staining for PRL was similar in both groups, before the addition of cabergoline. Responsive patients were followed for at least 12 months on combination treatment and persisted with normal IGF-I levels. Patients with baseline %ULNR IGF-I up to 220% and/or GH up to 5 ng/ml were those who benefited the most from combination treatment. No patients with %ULNR-IGF-I > 250% reached normalization of IGF-I levels. Our findings demonstrated that the addition of cabergoline, even at relatively low doses, is effective in both short- and long-term control of IGF-I levels in acromegalic patients partially responsive to octreotide LAR, particularly in those with mild/moderately elevated GH/IGF-levels, irrespective of prolactin status.