The effect of fenoldopam, a dopaminergic agonist, on renal hemodynamics

Abstract

Fenoldopam, a dopaminergic agonist, was administered intravenously to 18 healthy male subjects in doses ranging from 0.025 to 1.0 microgram/kg/min for 2 hours. Three subjects were studied in a three-way crossover of fenoldopam at doses of 0.025, 0.10, and 0.50 microgram/kg/min. Fenoldopam decreased diastolic blood pressure and increased pulse rate without changing systolic blood pressure. Fenoldopam produced dose-related increases in para-aminohippuric acid clearance up to 75% at the 0.50 microgram/kg/min dose. This increase in renal blood flow was accompanied by increases in urine volume, water, and solute excretion; glomerular filtration rate was unchanged. Doses greater than 0.25 microgram/kg/min caused flushing and nasal congestion. The dopamine receptor antagonist metoclopramide (0.1 mg/kg/hr) did not block the systemic hemodynamic effects of fenoldopam but attenuated the increase in para-aminohippuric acid clearance. Fenoldopam plasma levels achieved steady state between 30 and 120 minutes after the start of the infusion and were linear with respect to infusion rate. Our findings show that intravenous fenoldopam causes systemic arteriolar vasodilation, accompanied by renal vasodilation and increased sodium excretion.

Lithium and the renal response to gludopa, fenoldopam and dopamine [letter; comment]

“…Possibly there is a difference in salt status of the subjects studied at the beginning of the studies, which might influence the results. In fact Schoors & Dupont (1990) observe a higher sodium excretion at baseline during the study day without lithium than was observed in our (Girbes et al, 1990) Allison et al (1987), who reported a dose-related decrease in diastolic blood pressure to a maximum of 6 mm Hg during fenoldopam infusion of 0.50 ,ug kgmin-. In hypertensive patients however, a marked decrease in blood pressure is found (Glueck et al, 1987;Murphy et al, 1987;Ventura et al, 1984 (1984).…”

Effect of Fenoldopam Mesylate in Critically Ill Patients at Risk for Acute Renal Failure is Dose Dependent

“…In low doses, it improves renal blood flow and glomerular filtration rate in both animals and healthy human volunteers. [10,11] Because of the receptor selectivity of fenoldopam, there is interest in its use as a renoprotective agent, although data regarding its effectiveness are contradictory. Small trials suggest fenoldopam can preserve renal function after ischemic injury during coronary artery bypass grafting or aortic aneurysm repair.…”

“…Like low-dose dopamine, it increases renal blood flow and glomerular filtration rate in both animals and healthy human volunteers. [10,11] Studies on the effectiveness of fenoldopam in preventing ARF in high-risk patients are conflicting. [12 -15] Furthermore, any salutary effects of fenoldopam on renal function may be dose dependent.…”

Lithium and the natriuretic response to gludopa, fenoldopam and dopamine [letter; comment]

“…Therefore, in the in vivo situation, the increase in PRA after fenoldopam could, at least in part, be related to the fall in blood pressure, resulting in a baroreflex-mediated increase in sympathetic tone, and hence Padrenoceptor-mediated renin release. Girbes et al (1990) did not provide any data on the blood pressure response to fenoldopam, but others have observed marked reductions in blood pressure in healthy volunteers, using similar doses (Allison et al, 1987). Using an infusion rate of fenoldopam of 0.05 ,ug kg-' min-1, a nondepressor dose which increases renal blood flow, Hughes et al (1988) could not demonstrate any change in PRA.…”

“…Schoors refers to Allison et al (1987), who reported a dose-related decrease in diastolic blood pressure to a maximum of 6 mm Hg during fenoldopam infusion of 0.50 ,ug kgmin-. In hypertensive patients however, a marked decrease in blood pressure is found (Glueck et al, 1987;Murphy et al, 1987;Ventura et al, 1984).…”