IV tobramycin was associated with a greater urinary protein leak [ mean difference between treatments 0.59 mg/24hr ( 0.30 to 0.87 ) , p = 0.0005 ] and higher urinary levels of markers of acute renal tubular injury : N-acetylglucosaminidase [ 0.72 IU/mmol ( 0.37 to 1.07 ) , p = 0.0004 ] , alanine aminopeptidase [ 1.19 IU/mmol ( 0.70 to 1.68 ) , p = 0.0001 ] , and 2-microglobulin [ 0.44 g/mmol ( 0.16 to 0.72 ) , p = 0.0046 ] than TNS .