Progressive Hearing Loss among Patients with Cystic Fibrosis and Parenteral Aminoglycoside Treatment.

Objective: Hearing loss is a significant and growing problem as patients with cystic fibrosis (CF) live longer and experience frequent courses of intravenous aminoglycoside antibiotics (hereafter, "IVs"). This study seeks to document that risk in a large adult population with CF, accounting for age and aminoglycoside exposure.

Study Design: Retrospective case review of patients with CF who had multiple audiograms over years.

Setting: Tertiary care cystic fibrosis setting.

Subject And Methods: The first and last audiograms recorded over a 10-year period were compared for 165 adult patients with CF. Patients were divided into 3 study groups: 34 patients with no intervening aminoglycoside IVs (0 IVs), 103 patients with 1 to 9 IVs, and 28 patients with ≥10 IVs. Threshold shift (TS) between the audiograms were examined for the 3 groups before and after age/sex adjustments. Two new hearing loss metrics were tested.

Results: At first examination, 48% of patients (average age, 30.0 years) already had hearing loss. At last examination (average, 4.4 years later), 64% of the patients had hearing loss even with age/sex adjustment. Use of the age/sex hearing threshold adjustment eliminated the TS in the 0 IVs group. Two new metrics calculated for each patient demonstrated that 48% of patients who had 1 to 9 IVs had ototoxic scores, while almost 80% of the ≥10 IV group had ototoxic scores.

Conclusion: The majority of adult patients with CF are (often repeatedly) exposed to parenteral aminoglycosides and lose hearing at a rate that far exceeds that predicted from aging alone.