Nephrotoxicity, which may occur more often with telavancin than with vancomycin but has not been associated with dalbavancin or oritavancin With telavancin, QTc prolongation Nephrotoxicity with telavancin is more likely in patients with known kidney dysfunction, disorders that predispose to kidney dysfunction (eg, diabetes, hypertension, heart failure), or use of potentially nephrotoxic drugs.