Dopamine does not enhance furosemide-induced natriuresis in patients with congestive heart failure

The objective of this study was to determine whether the addition of low-dose (renal-dose) dopamine to furosemide therapy enhances natriuresis in patients with compensated congestive heart failure, New York Heart Association Class II or III. We performed a randomized, controlled, open-label, crossover study wherein urinary sodium, creatinine, and furosemide excretion rates and GFR determined by inulin clearance rates were measured during each of three treatment interventions: furosemide infusion alone, dopamine infusion alone, and furosemide and dopamine infusions administered concurrently. Six of eight recruited subjects (4 male, 2 female) were able to complete the study. The baseline sodium excretion rate after equilibration on a metabolic diet was 6.7 +/- 0.7 mEq (mean +/- SE) over 3 h. Infusion of dopamine alone caused a slight nonsignificant increase in natriuresis to 36.7 +/- 8.5 mEq/3 h. Furosemide alone markedly increased sodium excretion to 276.6 +/- 47.2 mEq/3 h. No significant additional increment in natriuresis occurred when dopamine and furosemide were administered concurrently (253.8 +/- 73.6 mEq/3 h). Neither dopamine, furosemide, or their coadministration affected GFR. In conclusion, infusion of low-dose dopamine does not enhance furosemide-induced urinary sodium excretion rates in patients with compensated congestive heart failure, New York Heart Association Class II or III.