Intravenous urography with iopamidol in children with reflux and obstructive nephropathy: effects on glomerular and tubular functions and the renin-angiotensin-aldosterone system

Twenty-seven children [2 with chronic renal failure (CRF)] with reflux or obstructive nephropathy underwent intravenous urography with iopamidol 370, a nonionic contrast medium 1 (CM), osmolality 796 mosmol/kg, for renal growth evaluation. Mean iopamidol dosing was 1.69 ml/kg (range 1.22–2.42); the 2 children with CRF received 2 and 2.42 ml/kg respectively. One hour after infusion a significant decrease in haematocrit, haemoglobin, plasma sodium (Na+), chloride (Cl−), renin activity and aldosterone was observed, consistent with a possible plasma volume expansion due to the slightly hypertonic CM. At the same time there was a significant increase in fractional excretion of Na+, Cl− and potassium, probably due to the haemodynamic effects and tubular response to a substance acting as on osmotic diuretic. The −24 to +48 h monitoring of albuminuria, beta-2-microglobulin excretion, and in 4 children excretion ofN-acetyl-β-glucosaminidase and alanine-aminopeptidase did not show any relevant nephrotoxicity. No untoward effect of clinical relevance was observed.