Dostinex® Pr
Paladin
Cabergoline
Dopamine Receptor Agonist
Pharmacology
Pharmacodynamic Properties: Cabergoline, the active ingredient in Dostinex, is a dopaminergic ergoline derivative endowed with a potent and long-lasting prolactin-lowering activity. It acts by direct stimulation of the D2-dopamine receptors on pituitary lactotrophs, thus inhibiting prolactin secretion. In rats the compound decreases prolactin secretion at oral doses of 3 to 25 µg/kg, and in vitro at a concentration of 45 pg/mL. In addition, cabergoline exerts a central dopaminergic effect via D2 receptor stimulation at oral doses higher than those effective in lowering serum prolactin levels.
The long-lasting prolactin-lowering effect of cabergoline is probably due to its long persistence in the target organ as suggested by the slow elimination of total radioactivity from the pituitary after a single oral dose in rats (t1/2 of approximately 60 hours).
The pharmacodynamic effects of cabergoline have been studied in healthy volunteers, puerperal women and hyperprolactinemic patients. After a single oral administration of cabergoline (0.3 to 1.5 mg), a significant decrease in serum prolactin levels was observed in each of the populations studied. The effect is prompt (within 3 hours from administration) and persistent (up to 7 to 28 days in healthy volunteers and hyperprolactinemic patients, and up to 14 to 21 days in puerperal women). The prolactin lowering effect is dose-related both in terms of degree of effect and duration of action.
With regard to the endocrine effects of cabergoline not related to the antiprolactinemic effect, available data from humans confirm the experimental findings in animals indicating that the test compound is endowed with a selective action with no effect on basal secretion of other pituitary hormones or cortisol. The pharmacodynamic actions of cabergoline not correlated with the therapeutic effect relate only to blood pressure decrease. The maximal hypotensive effect of a single dose usually occurs during the first 6 hours after drug intake and is dose-dependent both in terms of maximal decrease and frequency.