Vancomycin injection and Ototoxicity

Intravenous use of vancomycin may cause damage to the auditory branch of the eighth cranial nerve. Permanent hearing loss has been reported. Tinnitus sometimes precedes the onset of deafness, which may progress despite withdrawal of the drug. Therapy with vancomycin, particularly if prolonged (> 10 days), should be administered cautiously in patients with preexisting auditory impairment or tinnitus, since it may delay the recognition or confound the diagnosis of a drug-induced ototoxic effect. To minimize the risk of toxicity, the usual dosage should not be exceeded, use with other ototoxic agents should be avoided, and serum drug concentrations should be periodically determined and dosage adjusted to maintain desired levels. Ototoxicity has generally been associated with serum vancomycin levels of 80 to 100 mcg/mL, although toxic reactions have also been reported at levels as low as 25 mcg/mL. Serial audiograms should be obtained in patients old enough to be tested, and the dosage reduced or therapy withdrawn promptly if signs and symptoms of toxicity develop.

Oral vancomycin is generally not associated with systemic toxicity due to poor absorption from the gastrointestinal tract. However, clinically significant serum concentrations have been reported in some patients following multiple oral doses of vancomycin for active Clostridium difficile pseudomembranous colitis. Therefore, when vancomycin is administered orally, clinicians may want to heed the usual warnings and precautions associated with intravenous use of the drug.