RESUMO
The dose limiting side effect of cisplatin is nephrotoxicity. The aim of this study was to investigate tubular function in children who have received cisplatin and forced diuresis. We performed a cohort study on 20 children under 15 years of age with various type of malignancy on cisplatin-based chemotherapy. Twenty-four-hour urine was collected in three periods: before the first, third, and fifth doses of cisplatin administration to check urine for sodium (Na), magnesium (Mg), uric acid, creatinine (Cr), phosphorus (P), calcium (Ca), beta-2 microglobulin, and N-acetyl-beta-D-glucosaminidase (NAG) levels. At the same time, blood samples were taken to check serum Cr, Na, Mg, Ca, P, and uric acid levels. Then, we compared the mean of glomerular filtration rate (GFR); fraction excretions (FE,%) of Na, Mg, and uric acid; tubular phosphorous reabsorption (TPR,%), 24-hour urine Ca (mg); urine beta-2 microglobulin (mcg/mL); and NAG (IU/L) in three periods of cisplatin administration. The FE of Na, Mg, and urine beta-2 microglobulin increased after administration of cisplatin but TPR, FE, uric acid, and NAG decreased in the 2nd and 3rd period compared to 1st period. GFR revealed a little change that was not significant. Urine calcium was decreased significantly in the second and third periods of cisplatin administration. Since the patients were hydrated for forced diuresis and received magnesium sulfate to prevent nephrotoxicity, we did not see significant tubular dysfunction. But we saw that urine calcium excretion decreased after cisplatin injection without any change in serum calcium in spite of preventive measures.
