The effect of quinagolide and cabergoline, two selective dopamine receptor type 2 agonists, in the treatment of prolactinomas

• Published in: Clinical endocrinology (Oxford) 2000-07, Vol.53 (1), p.53-60
• Main Authors: Di Sarno, Antonella, Landi, Maria Luisa, Marzullo, Paolo, Di Somma, Carolina, Pivonello, Rosario, Cerbone, Gaetana, Lombardi, Gaetano, Colao, Annamaria
• Format: Article
• Language: English
• Subjects: Adult; Aminoquinolines - adverse effects; Aminoquinolines - therapeutic use; Biological and medical sciences; Cabergoline; Cross-Over Studies; Dopamine Agonists - adverse effects; Dopamine Agonists - therapeutic use; Ergolines - adverse effects; Ergolines - therapeutic use; Female; Hormones. Endocrine system; Humans; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Pharmacology. Drug treatments; Pituitary Neoplasms - blood; Pituitary Neoplasms - drug therapy; Pituitary Neoplasms - pathology; Prolactin - blood; Prolactinoma - blood; Prolactinoma - drug therapy; Prolactinoma - pathology; Receptors, Dopamine D2 - agonists; Treatment Outcome
• ISSN: 0300-0664; 1365-2265
• DOI: 10.1046/j.1365-2265.2000.01016.x

OBJECTIVE To compare effectiveness and tolerability of quinagolide (CV 205–502) and cabergoline (CAB) treatments in 39 patients with prolactinoma. STUDY DESIGN All 39 patients were treated first with quinagolide for 12 months and then with cabergoline for 12 months. A wash‐out period was performed in all patients after 12 months of both treatments in order to evaluate recurrence of hyperprolactinaemia. PATIENTS Twenty‐three patients with microprolactinoma (basal serum PRL levels 1620–18750 mU/l) and 16 patients with macroprolactinoma (basal serum PRL levels 4110–111000 mU/l), previously shown to be intolerant of bromocriptine. All patients had gonadal failure and 11 patients with macroprolactinoma had visual field defects. Five patients with macro‐ and one with microprolactinoma had previously undergone surgery. STUDY PROTOCOL The starting doses of quinagolide and CAB were 0.075 mg/day and 0.5 mg/week, respectively, subsequently increased up to 0.6 mg once daily and 1.5 mg twice weekly, respectively. Serum PRL levels were measured monthly for the first 3 months and then quarterly for 12 months. PRL levels were assayed weekly for the first month and then monthly during the wash‐out period. Tumour shrinkage was evaluated by serial magnetic resonance imaging (MRI) studies of the hypothalamus–pituitary region at study entry and after 6 and 12 months of both treatments in micro‐ and macroprolactinomas. RESULTS After 12 months of quinagolide treatment, serum PRL levels normalized in all 23 patients with microprolactinoma (100%) and in 14 out of 16 with macroprolactinoma (87.5%). A tumour volume reduction of greater than 80% was documented by MRI studies in five of 23 (21.7%) patients with microprolactinoma and in four of 16 (25%) with macroprolactinoma. All patients had recurrence of hyperprolactinaemia after 15–60 days withdrawal of quinagolide treatment. However, before starting CAB treatment basal PRL levels were significantly lower than before quinagolide treatment both in microprolactinomas (4667.4 ± 714.7 vs. 2636.1 ± 262.3 mU/l, P = 0.006) and in macroprolactinomas (24853.1 ± 7566.7 vs. 3576.6 ± 413.0 mU/l, P = 0.013). After 12 months of CAB treatment, serum PRL levels normalized in 22 out of 23 patients with microprolactinoma (95.6%) and in 14 out of 16 with macroprolactinoma (87.5%). No difference in PRL nadir was found after quinagolide and CAB treatments both in micro 174.6 ± 30.6 vs. 169.8 ± 37.9 mU/l, P = 0.5) and in macroprolactinomas (277.5 ± 68.4