Effect of fenoldopam on the acute and subacute nephrotoxicity produced by amphotericin B in the dog.

The effect of the selective dopamine DA1 receptor agonist fenoldopam (1 microgram/kg/min i.v.) on the acute nephrotoxic response to amphotericin B (2 mg/kg i.v.) has been studied in the anesthetized dog. Animals were prepared for the measurement of blood pressure, renal blood flow, urine flow, glomerular filtration rate and sodium and potassium excretion. Amphotericin B was given over 20 min and the animals were followed for an additional 160 min. The fenoldopam infusion was started 20 min before amphotericin B and was continued for the duration of the experiment. In control animals, amphotericin B markedly increased renal vascular resistance without affecting blood pressure and thus produced a significant reduction in renal blood flow. The renal vasoconstrictor response to amphotericin B was not attenuated by fenoldopam. Concomitant with the renal vasoconstriction produced by amphotericin B was a marked reduction in glomerular filtration rate, sodium excretion and urine flow rate, which lasted for at least 160 min after amphotericin B treatment. Fenoldopam did not have any effect on the initial reductions in glomerular filtration rate, sodium excretion and urine flow rate but did produce a significant return of these parameters toward control levels by 160 min, despite the continued renal vasoconstriction. The effect of fenoldopam (0.5 microgram/kg/min) given continuously by i.v. infusion on the subacute nephrotoxic response produced by amphotericin B given every other day for 8 days was also investigated. One day after the start of the fenoldopam infusion, venous samples were drawn for the analysis of serum creatinine and blood urea nitrogen.(ABSTRACT TRUNCATED AT 250 WORDS)