Urinary beta 2-microglobulin: early indicator of high dose cisdiamminedichloroplatinum nephrotoxicity? Influence of furosemide.

To evaluate the efficacy of beta 2-microglobulin as an indicator of cisplatinum nephrotoxicity, creatinine clearance and urinary beta 2-microglobulin were measured in 19 patients during 5 h after administration of a single dose of 80 mg/m2 cisplatinum. Eleven patients received furosemide as a concomitant therapy. Serum creatinine and beta 2-microglobulin remained unchanged. A decrease of creatinine clearance was observed. Urinary beta 2-microglobulin increased between 1 and 3 h after administration. This suggests transient tubular damage immediately after the treatment course. The concomitant administration of furosemide does not modify these results. However, patients who developed long-term nephrotoxicity had no early rise of urinary beta 2-microglobulin excretion; thus, it is not possible to predict cumulative nephrotoxicity by measuring beta 2-microglobulin immediately after the first course of high-dose cisplatinum.