Furosemide use ( odds ratio [ OR ] 2.91 , 95 % CI 1.64-5 .15 ) , hypertension ( OR 2.74 , 95 % CI 1.5-5 .0 ) , and vancomycin trough concentration 16.2 g/mL ( OR 2.33 , 95 % CI 1.25-4 .44 ) were each associated with nephrotoxicity during vancomycin therapy .