title: Effect of 4 weeks of octreotide treatment on prolactin, thyroid stimulating hormone and thyroid hormones in acromegalic patients. A double blind placebo-controlled cross-over study.
abstract: We aimed to test the hypothesis, that octreotide has a suppressive effect on unstimulated and TRH-stimulated PRL levels in both normo- and hyperprolactinaemic acromegalic patients, and besides to evaluate the effect of octreotide on unstimulated TSH and thyroid hormones. The present study is a doubleblind placebo-controlled cross-over trial; the 12 acromegalic patients were treated with octreotide or placebo (300 micrograms/d) for 4 weeks separated by a 12 weeks washout period. Before and after each 4 weeks period a TRH-test (200 micrograms iv) was performed and serum GH and PRL levels were determined. Serum TSH and thyroid hormones were determined after 0, 2, 3, and 4 weeks. In the whole group unstimulated PRL levels were 18 micrograms/l +/- 5 before and 7 micrograms/l +/- 1 during octreotide treatment (p < 0.01). The PRL lowering effect of octreotide was significantly more pronounced in hyperprolactinemic patients compared to normoprolactinaemic patients (p < 0.05). Patients with the highest pretreatment PRL levels had the most pronounced percentage suppression of unstimulated PRL levels during octreotide treatment. Eight out of 12 patients had a TRH-stimulated PRL response > or = 100%, both during placebo and octreotide treatment, but in the group as a whole maximal TRH-stimulated PRL levels were suppressed during octreotide treatment, PRL levels were 50 micrograms/l +/- 20 before and 18 micrograms/l +/- 3 during octreotide treatment (p < 0.05). Unstimulated GH levels were 48 mU/l +/- 15 before and 13 mU/l +/- 2 during octreotide treatment (p < 0.01). Serum total T3 was significantly reduced during octreotide treatment (p < 0.05); serum TSH, total T4 or free T4 index were not significantly changed during treatment. We conclude that patients with acromegaly and hyperprolactinemia will normalize PRL levels during 4 weeks of octreotide treatment and octreotide will reduce total T3 levels in acromegalic patients.
authors.affiliation: Department of Medical Endocrinology, Odense University Hospital, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Andersen
authors.forename: T B
authors.initials: TB
authors.lastname: Hansen
authors.forename: J
authors.initials: J
authors.lastname: Bollerslev
authors.forename: P
authors.initials: P
authors.lastname: Bjerre
authors.forename: H D
authors.initials: HD
authors.lastname: Schrøder
authors.forename: C
authors.initials: C
authors.lastname: Hagen
mesh_terms: D000172:Acromegaly / Q000097:blood*; D000328:Adult; D000368:Aged; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006728:Hormones / Q000097:blood* / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000494:pharmacology*; D011388:Prolactin / Q000097:blood; D013963:Thyroid Hormones / Q000097:blood; D013972:Thyrotropin / Q000097:blood
chemical_list: D006728:Hormones; D013963:Thyroid Hormones; D011388:Prolactin; D013972:Thyrotropin; D015282:Octreotide