Discordant responses of prolactinoma to two different dopamine agonists.
AbstractA 19-year-old woman presented with headaches, temporal lobe epilepsy and primary amenorrhoea. There was a family history of multiple endocrine adenomatosis. Investigation revealed normal visual fields and acuity, hyperprolactinaemia (48 000 mU/l) and a very large pituitary tumour with extrasellar spread. Treatment with bromocriptine reduced the tumour size and the prolactin level to 2440 mU/l. Six months after the start of therapy, resistance to bromocriptine developed and the prolactin concentration progressively rose to pretreatment levels, despite increasing the dose of bromocriptine to 40 mg/d. At this stage treatment with a second dopamine agonist, pergolide, was effective in reducing the prolactin concentration to normal within four months. Serial CT scans at 1, 6 and 12 months on dopamine agonist therapy showed a progressive decrease in tumour size, which seemed to be maintained even during the period of rising prolactin concentrations due to bromocriptine resistance. This case illustrates that during dopamine agonist therapy a discrepancy may exist in the clinical response as judged by reduction in tumour size and decrease in the circulating prolactin level. Furthermore, in patients with prolactinomas, pergolide may induce a response when resistance to bromocriptine develops.
CitationDiscordant responses of prolactinoma to two different dopamine agonists. 1986, 24 (4):421-6 Clin Endocrinol
- Effect of dopamine agonist withdrawal after long-term therapy in prolactinomas. Studies with high-definition computerised tomography.
- Authors: Johnston DG, Hall K, Kendall-Taylor P, Patrick D, Watson M, Cook DB
- Issue date: 1984 Jul 28
- Effect of bromocriptine and pergolide on pituitary tumor size and serum prolactin.
- Authors: Horowitz BL, Hamilton DJ, Sommers CJ, Bryan RN, Boyd AE 3rd
- Issue date: 1983 May-Jun
- Diagnosis and drug therapy of prolactinoma.
- Authors: Ciccarelli E, Camanni F
- Issue date: 1996 Jun
- The effect of dopamine agonist therapy on large functionless pituitary tumours.
- Authors: Grossman A, Ross R, Charlesworth M, Adams CB, Wass JA, Doniach I, Besser GM
- Issue date: 1985 May
- Failure of bromocriptine to maintain reduction in size of a macroprolactinoma.
- Authors: Breidahl HD, Topliss DJ, Pike JW
- Issue date: 1983 Aug 13