Are gentamicin and/or vancomycin associated with ototoxicity in the neonate? A retrospective audit

Abstract

Background: Aminoglycoside-induced ototoxicity has been reported in neonates but its incidence is poorly defined, whereas vancomycin-induced ototoxicity has not been reported in neonates.

Objective: To compare hearing test results in infants in a neonatal intensive care unit (NICU) who were or were not treated with extended interval gentamicin dosing and/or standard vancomycin dosing.

Method: A database of otoacoustic emissions (OAE), over a 5-year period of NICU admissions, was combined with databases of gentamicin and vancomycin dosing to compare patients treated or not treated with these antibiotics.

Results: A total of 2,347 OAE results was available. OAE failure rates were: no gentamicin and no vancomycin (noGnoV), 7% (85/1,233); gentamicin but no vancomycin (GnoV), 4% (42/949); vancomycin but no gentamicin (VnoG), 22% (9/41) and gentamicin and vancomycin (GandV), 14% (17/124). Compared to noGnoV there was a decreased risk of OAE failure in GnoV (p = 0.022, OR 0.64, 95% CI 0.44-0.94) and an increased risk in VnoG (p = 0.003, OR 3.46, 95% CI 1.54-7.75) and GandV, (p = 0.006, OR 2.20, 95% CI 1.26-3.83).

Conclusions: Gentamicin, as used and evaluated in this audit, showed no evidence of an increased risk of ototoxicity; what was observed was a statistically significant decrease in OAE failure rate. Vancomycin, by contrast, was associated with ototoxicity.