The pharmacology of fenoldopam.

Fenoldopam is a selective dopamine1 (DA1) receptor agonist. Most of the DA1 receptor agonist activity of fenoldopam resides in the R-enantiomer, which also shows weaker alpha 2-adrenoceptor antagonist activity Fenoldopam produces vasodilation in vascular beds that are rich in vascular DA1 receptors, eg, renal and mesenteric receptors, and produces an increase in renal blood flow at doses that do not affect blood pressure. At higher doses, fenoldopam lowers blood pressure but still maintains renal perfusion. In addition to its renal vasodilator activity, fenoldopam is natriuretic, possibly resulting from a direct effect of DA1 receptors on the proximal convoluted tubule. In animals with spontaneous or drug-induced renal failure, fenoldopam improves renal function.