The association between the cumulative dose of aminoglycoside exposure and hearing loss in children with cystic fibrosis

Abstract

<b>Introduction-Aim:</b> Pulmonary exacerbations increase the requirement of aminoglycoside (AG) antibiotics in patients with cystic fibrosis (CF). Some studies show that AGs have cumulative effect for ototoxicity. We aimed to investigate the relationship between&nbsp;AG exposure and hearing loss in patients with CF. <b>Materials-Methods:</b> The ongoing multicenter study included 55 patients with CF aged between 5-18 with a history of AG exposure.&nbsp;Standard pure tone audiometry, extended high frequency audiometry and DPOAE tests were perfomed. The patients were screened for m.1555A&gt;G mitochondrial mutation. <b>Results:</b> Mean age was 12 ±3.6 years and 56.4% (n=31) were male. 27.3% (n=15) of them had received parenteral AG more than 5 courses/lifetime.&nbsp;Hearing loss was detected in 7 ears in at least one frequency in standard audiometry. A decrease in high frequency audiometry thresholds was observed in 25 (24.2%) of 103 ears which were normal in standard audiometry. A decrease in high frequency hearing thresholds was detected in at least one ear in 14 patients (25.4%).&nbsp;While the rate of hearing loss was found to be 20% (n=8) in those who had a history of taking less than 5 courses of AG, it was 40% (n=6) in patients received more than 5 courses(p=0.12). No m1555A&gt;G mutation was detected in 28 patients whose mutation analysis were completed. <b>Conclusion:</b> As AG ototoxicity occurs primarily at high frequencies, extended high frequency audiometry is important in early detecting otoxicity.&nbsp;All CF patients with a history of AG exposure should be evaluated for hearing loss since hearing loss may only be noticed in late period by patients and caregivers.