title: Effects of a chronic treatment with octreotide in patients with functionless pituitary adenomas.
abstract: The effects of a chronic treatment with octreotide were evaluated in 19 patients affected with functionless pituitary adenomas. Octreotide caused a significant decrease of GH and IGF-I levels in all the patients and no significant change in thyroid, adrenal and gonadal function. In contrast, during the therapy, the glucose response to an oral glucose tolerance test considerably increased and was delayed, while the insulin response decreased and was delayed. Serum alpha-subunit (alpha-SU) was above normal in 10 of 16 patients in which this evaluation was performed: octreotide caused a significant decrease (p < 0.01) of alpha-SU levels in 6 of these 10 patients. Octreotide did not induce any significant change in visual fields except in 1 patient, who had a great improvement of visual perimetry and a decrease of alpha-SU levels but unmodified CT scan features. In our series of patients, octreotide was ineffective in reducing tumor mass. The efficacy of octreotide might rely on the presence of somatostatin receptors on adenoma-cell membranes. Therefore patients with functionless adenomas to be treated with octreotide might be identified with pituitary scintiscan using the recently available labeled 111In-octreotide.
authors.affiliation: Department of Medical-Surgical Endocrinology, University Federico II, School of Medicine, Naples, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Merola
authors.forename: A
authors.initials: A
authors.lastname: Colao
authors.forename: D
authors.initials: D
authors.lastname: Ferone
authors.forename: A
authors.initials: A
authors.lastname: Selleri
authors.forename: A
authors.initials: A
authors.lastname: Di Sarno
authors.forename: P
authors.initials: P
authors.lastname: Marzullo
authors.forename: B
authors.initials: B
authors.lastname: Biondi
authors.forename: R
authors.initials: R
authors.lastname: Spaziante
authors.forename: E
authors.initials: E
authors.lastname: Rossi
authors.forename: G
authors.initials: G
authors.lastname: Lombardi
mesh_terms: D000236:Adenoma / Q000188:drug therapy*; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D005951:Glucose Tolerance Test; D015292:Glycoprotein Hormones, alpha Subunit / Q000097:blood; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D010911:Pituitary Neoplasms / Q000188:drug therapy*; D014057:Tomography, X-Ray Computed; D014794:Visual Fields
chemical_list: D001786:Blood Glucose; D015292:Glycoprotein Hormones, alpha Subunit; D007328:Insulin; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D015282:Octreotide