THE ASSOCIATION BETWEEN AMINOGLYCOSIDE EXPOSURE AND OTOTOXICITY IN CHILDREN WITH CYSTIC FIBROSIS.

ABSTRACT

INTRODUCTION: Pulmonary exacerbations increase the requirement of aminoglycoside (AG) antibiotics in people with cystic fibrosis (pwCF). Several studies have shown that AGs have a cumulative effect on ototoxicity. We aimed to investigate the relationship between AG exposure and ototoxicity by using three different methods in patients with CF. MATERIALS-METHODS: The multicenter study included 121 pwCF aged between 5-18 years with a history of parenteral AG exposure. Standard pure tone audiometry (sPTA), extended high frequency audiometry (EHF-PTA), and distortion-product otoacoustic emissions (DPOAE) tests were performed. Mitochondrial mutation analysis for m1555G>A was performed in 61 patients. RESULTS: Median age was 12.85 years and 52.1% (n=63) were male. 18.2% (n=22) of the patients had received parenteral AGs more than 5 courses/lifetime. Ototoxicity was detected in at least one of the tests in 56.2% (n= 68) of the patients. Only 10.7 % (n=13) of the patients had reported a symptom indicating ototoxicity. 30.3% (n=30) of the patients had ototoxicity in the low-exposure group while it was 45.5% (n=10) in the high-exposure group according to EHF-PTA (p>0.05). Median number of parenteral amikacin courses was significantly higher in the ototoxic group [2(1.25-5.75) vs 2(1-3); p=0.045]. No m1555A>G mutation was detected in 61 patients who screened for mitochondrial mutation analysis. CONCLUSION: As AG ototoxicity occurs primarily at high frequencies, EHF-PTA is important in early detecting otoxicity. EHF-PTA and DPOAE detected ototoxicity in some patients with normal PTA results. All pwCF with a history of AG exposure should be evaluated for hearing loss since symptoms may only be noticed in the late period.