330 influence of biological maturation on the determin-ants of response to furosemide

ABSTRACT The effect of age on the determinants of the diuretic response to furosemide was evaluated in 22 infants (9 premature infants 2-6 days old and 13 infants 1 to 36 months old). The

urinary excretion of furosemide, and therefore the presentation of the drug to its site of action, was significantly slower (p < 0.005) in the premature infants (t½ = 26.5 ± 31.2 h) than

in the older children (t½ = 1.79 ± 1.26 h). Despite the prolonged time of drug excretion, the younger infants excreted significantly less of the administered dose in the urine (20.7 ± 17.5%

vs. 49.2 ± 22.9%; p < 0.01). All but one infant in each group exhibited an increase in urine flow after furosemide administration and demonstrated a linear relationship between furosemide

excretion rate and diuretic response. The increase in urine flow rate per unit furosemide excretion rate was significantly greater in the premature infants (p < 0.001). The results

suggest that the immaturity in at least two aspects of renal function contribute to the pattern of diuretic response seen in very young infants. Immaturity of organic ion transport limits

the rate and amount of drug reaching its site of action. However, the inability of parts of the tubule not effected by the diuretic to compensate for the increased electrolyte and water loss

leads to an enhanced sensitivity to the drug which is excreted. ARTICLE PDF AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * Dept. of Pediatrics, Div. Clin. Pharm., Univ. of Minn. Med. School,

Minneapolis, 55455 Thomas P Green & B L Mirkin Authors * Thomas P Green View author publications You can also search for this author inPubMed Google Scholar * B L Mirkin View author

publications You can also search for this author inPubMed Google Scholar RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Green, T., Mirkin, B. 330

INFLUENCE OF BIOLOGICAL MATURATION ON THE DETERMIN-ANTS OF RESPONSE TO FUROSEMIDE. _Pediatr Res_ 15 (Suppl 4), 495 (1981). https://doi.org/10.1203/00006450-198104001-00341 Download citation

* Issue Date: 01 April 1981 * DOI: https://doi.org/10.1203/00006450-198104001-00341 SHARE THIS ARTICLE Anyone you share the following link with will be able to read this content: Get

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