From postinfusion to end of bypass , the median percentage of time vancomycin concentrations remained greater than 15 g/mL was 100 % ( interquartile range [ IQR ] , 72.6 % -100 % ) for weight-based dosing versus 43.7 % ( IQR , 28.7 % -53.4 % ) for standard dosing ( P = .0005 ) .