Aminoglycoside ototoxicity susceptibility in cystic fibrosis

Ototoxicity is a recognised dose-related complication of aminoglycoside antibiotics. Predisposition to these ototoxic effects, even when levels are within the therapeutic range, is associated with an inherited mitochondrial DNA mutation known as m.1555A>G.1 2 We report a case of a 22-year-old woman with cystic fibrosis (CF), genotype delta F508 homozygous, with bilateral high frequency hearing loss. This was discovered when an audiogram (not previously performed) was requested for routine screening by our centre before commencement of nebulised TOBI (preservative-free pH-adjusted preparation of tobramycin for inhalation). She had a history of diabetes mellitus, exocrine pancreatic insufficiency and developed chronic Pseudomonas aeruginosa infection when aged 5 …