A Prospective Study on the Vestibular Toxicity of Gentamicin in a Clinical Setting

Objective Gentamicin is a widely used aminoglycoside with ototoxicity as a known adverse effect. Because of the difficulty in clinical recognition, the prevalence of gentamicin ototoxicity in practice is thought to be higher than reported. This study aimed to prospectively assess the effect of gentamicin on vestibular function and whether ototoxicity is underrecognized. Study Design Single-center, prospective, nonblinded trial. Setting Inpatient tertiary hospital setting followed by vestibular outpatient clinic review. Patients Forty-eight patients undergoing a urologic procedure were recruited, with 24 and 17 patients having one or two follow-up tests, respectively, after initial gentamicin administration. Intervention(s) Single dose of gentamicin during a urologic procedure. Main Outcome Measure(s) Gains for the vestibuloocular reflex (VOR) were measured using the video head impulse test before receiving gentamicin and at two other timepoints after gentamicin. The gains in VOR were then compared with previous testing sessions to determine if there was a deterioration after gentamicin use. Results Before receiving gentamicin, the gains for horizontal VOR were measured for 48 patients. The gains were measured a second time for 24 patients at varying durations postgentamicin (1-56 d) and a third time for 17 patients (14-152 d) postgentamicin. The mean VOR gain for Timepoints 1, 2, and 3 were 0.72 +/- 0.13, 0.75 +/- 0.16, and 0.79 +/- 0.18, respectively. Linear-mixed model with repeated-measure analysis revealed no significant difference in VOR gain between Timepoints 1 and 2 (p = 0.19). Conclusion There was no significant effect observed on mean VOR gain decrement after a single dose of gentamicin.