TREATMENT OF MACROPROLACTINOMA WITH THE NEW POTENT NONERGOT D2-DOPAMINE AGONIST QUINAGOLIDE AND EFFECTS ON PROLACTIN LEVELS, PITUITARY-FUNCTION, AND THE RENIN-ALDOSTERONE SYSTEM - RESULTS OF A CLINICAL LONG-TERM STUDY
T. Nickelsen et al., TREATMENT OF MACROPROLACTINOMA WITH THE NEW POTENT NONERGOT D2-DOPAMINE AGONIST QUINAGOLIDE AND EFFECTS ON PROLACTIN LEVELS, PITUITARY-FUNCTION, AND THE RENIN-ALDOSTERONE SYSTEM - RESULTS OF A CLINICAL LONG-TERM STUDY, Arzneimittel-Forschung, 43-1(4), 1993, pp. 421-425
The oral non-ergot D2-dopamine agonist quinagolide (CV205-502, CAS 870
56-78-8) has proven to be highly effective in suppressing elevated pro
lactin (PRL) levels. It was the aim of this study to search for possib
le interference of the drug with other endocrine systems which are par
tly under dopaminergic control, and to compare such effects to those o
f previously investigated prolactin inhibitors. Twelve patients suffer
ing from macroprolactinoma were treated for at least 6 months with dai
ly doses ranging from 50 up to 300 mug During the first two months, in
dividual doses were gradually increased either until serum PRL levels
reached the normal range (n = 7) or until side effects made a further
dose increase intolerable (n = 5). Mean basal PRL levels fell from 255
+/- 65 (SEM) ng/ml before treatment to 19 +/- 8 ng/ml, after the defi
nite dose was reached (p < 0.01). Luteinizing hormone (LH) rose from 0
. 6 +/- 0. 8 (SD) to 1.7 +/- 1.6 mU/ml (p < 0.05). While basal levels
of aldosterone, renin, follicle-stimulating hormone (FSH), triiodothyr
onine (T3), testosterone, and estradiol in females were not affected b
y the treatment, we found a significant rise in thyroxine (T4) and a d
ecrease of estradiol in males. Blood pressure and renal clearances of
creatinine, sodium, potassium, and chloride failed to show any signifi
cant change. Following stimulation with metoclopramide, aldosterone an
d renin rose sharply before treatment was initiated When the test was
repeated during treatment, the increase of plasma renin was slightly d
ampened, whereas the rise of aldosterone remained unaffected The respo
nse of thyrotropin (TSH), LH and FSH to stimulation with thyrotropin-r
eleasing hormone (TRH) and luteinizing hormone-releasing hormone (LHRH
) dit not change during quinagolide treatment. It is concluded that qu
inagolide long-term treatment does not affect hormonal systems other t
han prolactin in a clinically relevant way.