Effects of prenalterol on renal function in patients after major vascular surgery

Hemodynamic and renal effects of prenalterol were studied in 13 mechanically ventilated patients on the first day after major vascular surgery. Prenalterol (1-[4-hydroxyphenoxy]-3-isopropylamino-2 propanol hydro-chloride), a partial beta-agonist with a predominant beta-1 and a weak beta-2-adrenoceptor activity, was infused into seven patients at rates of 0.5 and 1.0 microgram/kg.min (group A), and at a dose of 2.0 micrograms/kg.min in six patients (group B). Although no hemodynamic changes were observed in group A, systolic BP, mean BP, heart rate, and cardiac output increased significantly in group B. Catecholamine levels and plasma renin activity were unaltered in both groups, as was glomerular filtration rate. Renal blood flow did not change in group A but it increased by 25% in group B. Urine flow, fractional free water clearance, fractional sodium excretion, and fractional chloride excretion were unaltered in both groups. Fractional potassium excretion decreased by 20%, 22%, and 26% at the three infusion rates of prenalterol, respectively. We conclude that prenalterol does not directly influence renal function in the postoperative setting.