Aminoglycoside antibiotics cochleotoxicity in paediatric cystic fibrosis (CF) patients: A study using extended high-frequency audiometry and distortion product otoacoustic emissions

Abstract

Despite known ototoxic effects of aminoglycoside (AG) antibiotics, audiological assessment is not routinely undertaken in UK CF patients. Consequently, the incidence of hearing loss is not well established.

Objective: To document the incidence of hearing loss in cystic fibrosis (CF) children.

Design: Hearing function of 45 children from Great Ormond Street Hospital was assessed using pure-tone audiometry up to 20kHz and DPOAEs up to 8kHz.

Study sample: 39/45 of participants had received intravenous (IV) AGs, 23 of which received repeated IV AGs every 3 months.

Results: In this high exposure group, 8 (21%) had clear signs of ototoxicity; average 8-20kHz thresholds were elevated by ∼50dB and DPOAE amplitudes were >10dB lower at f2 3.2-6.3 kHz. The remaining 31/39 (79%) of AG exposed patients had normal, even exceptionally good hearing. The 21% incidence of ototoxicity we observed is substantial and higher than previously reported. However, our finding of normal hearing in children with equal AG exposure strongly suggests that other unknown factors, possibly genetic susceptibility, influence this outcome.

Conclusions: We recommend comparable auditory testing in all CF patients with high AG exposures. Genetic analysis may help explain the dichotomy in response to AGs found.