Physiologic disposition of pergolide.

Pergolide, a synthetic ergoline, is a potent long-acting dopaminergic drug effective in Parkinson's disease and amenorrhea-galactorrhea. After 138 micrograms 14C-pergolide orally to healthy subjects, radioactivity was present in plasma and red blood cells. Salivary radioactivity was one third to one tenth that in plasma. Radioactivity in plasma appeared after 15 to 30 min, peaked at 1 to 2 hr, and was barely detectable after 96 hr. Plasma radioactivity was not attributable to pergolide, and the levels did not correlate well with the duration of the prolactin-lowering effect induced by pergolide. Pergolide became bound to several plasma proteins and could not be displaced by other drugs that are also bound or by possible metabolites of pergolide. Radioactivity was eliminated as pergolide metabolites in urine (55%), feces (40%), and breath (5%, as 14CO2).