Newborn hearing screening: Tobramycin and vancomycin are not risk factors for hearing loss

Objective To investigate the chance of detecting hearing loss with neonatal hearing screening in relation to exposure to tobramycin and vancomycin. Study design Automated auditory brainstem response (A-ABR) hearing screening was performed in all neonates with at least one risk factor. Data on drug administration were abstracted from patient files. Exposure to these drugs was related to the result of hearing screening. In patients failing hearing screening, exposure to ototoxic medication was assessed in the light of other risk factors for hearing loss. Results Six hundred twenty-five patients were analyzed; 45 neonates failed hearing screening. Tobramycin, vancomycin, and furosemide were used in 508, 130, and 174 patients, respectively. Exposure to vancomycin, tobramycin, or furosemide or a combination, defined in terms of treatment duration, total dose, or serum concentrations of antibiotics, was not related to failure to pass A-ABR screening. Ototoxic medication was not the most probable risk factor in any of the patients with serum concentrations outside the therapeutic range. Conclusions Routine therapeutic drug monitoring of vancomycin and tobramycin in neonates for ototoxicity reasons is not helpful in detecting patients at risk for clinically important hearing loss in the 2- to 4-kHz range. A longer period of audiometric follow-up is needed to determine any long-term effects.