Nephrotoxicity developed at a median of 4.5 days ( interquartile range [ IQR ] 2.2-4 .9 ) peaked at 5.7 days ( IQR : 3.8-9 .6 ) , and resolved in 70.6 % of the cases within 16.5 days ( IQR : 6.0-17 .8 ) after onset .