Short- and long-term efficacy of combined cabergoline and octreotide treatment in controlling igf-I levels in acromegaly.
OBJECTIVE
Nearly 40% of acromegalic patients fail to control GH/IGF-I levels with somatostatin analogues (SA). Dopaminergic agonists (DA) are even less effective, but combination therapy with SA and DA normalizes IGF-I levels in 33-56% of patients not controlled by octreotide alone in short-term studies. This study was designed to evaluate short- and long-term efficacy of cabergoline in controlling IGF-I levels in acromegalic patients receiving octreotide.


METHODS
Open-label, single arm, prospective trial. Nineteen patients (14 females, 29-78 years of age) with high IGF-I on octreotide-LAR (30 mg/month IM) for > or =6 months were enrolled. Study I: Cabergoline (PO) was started at 1.0, increased to 2.0 and 3.5 mg/week, and withdrawn at 6-week intervals. IGF-I, GH, and PRL were measured at baseline and at 6-week intervals. Study II: Responder patients (IGF-I < or =1 ULN) resumed cabergoline at individual lowest effective doses and were evaluated at 6-month intervals for > or =12 months. Study III: Responders were withdrawn from octreotide and hormonally evaluated at 3-month intervals.


METHODS
Serum IGF-I (IRMA), GH (ICMA) and PRL (ICMA) levels were determined by commercially available kits.


RESULTS
Addition of cabergoline to octreotide-LAR normalized IGF-I levels in 7 of 19 patients (37%) during both short- and long-term follow-up (12-27 months, mean: 18 months). Octreotide withdrawal increased IGF-I levels in only 2 of 6 responder patients. Normalization of IGF-I levels by cabergoline was strongly associated with IGF-I < or =2.2 ULNR and/or GH < or =4.0 ng/ml under octreotide treatment.


CONCLUSIONS
Addition of cabergoline to octreotide was effective in both short- and long-term control of IGF-I in acromegaly, especially in patients with mild/moderately elevated GH/IGF-I levels during octreotide.
Mattar
Priscilla
P
Neuroendocrine Unit, Division of Endocrinology, Department of Medicine, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.
Alves Martins
Manoel Ricardo
MR
Abucham
Julio
J
D000172:Acromegaly / Q000097:blood / Q000188:drug therapy*; D000328:Adult; D000368:Aged; D000077465:Cabergoline; D018491:Dopamine Agonists / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D004873:Ergolines / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000037:antagonists & inhibitors*; D008875:Middle Aged; D015282:Octreotide / Q000627:therapeutic use*; D013004:Somatostatin / Q000031:analogs & derivatives
D018491:Dopamine Agonists; D004873:Ergolines; D013004:Somatostatin; D007334:Insulin-Like Growth Factor I; D000077465:Cabergoline; D015282:Octreotide