L-N-Acetylcysteine treatment is associated with improved hearing outcome in sudden idiopathic sensorineural hearing loss

Abstract

Conclusion: Combination therapy corticosteroids plus an oral antioxidant L-N-acetylcysteine (LNAC) was associated with improved hearing over corticosteroids alone, particularly at the 6-month follow-up and at high frequencies (i.e. 4000 Hz). This is the first report of a beneficial effect of LNAC in sudden idiopathic sensorineural hearing loss (SISNHL). Objective: To determine the association between antioxidant treatment and functional outcomes in SISNHL. Methods: This was a case-control study of adult patients with SISNHL, treated with oral prednisone plus intratympanic dexamethasone either alone or in combination with LNAC. The outcome measure was change in pure-tone thresholds at 500–4000 Hz. Hearing recovery was also recorded as the percentage of subjects with final pure-tone threshold average (PTA) within 50% of the difference between the initial value of the affected ear and the value of the unaffected ear. Comparisons were made between combination (corticosteroids plus LNAC) and single (no LNAC use) therapy groups. Results: At 6 months, the mean PTA improvements were 26.1 dB and 15.1 dB for the combination and single therapy groups, respectively (p = 0.046). Higher gains at 4000 Hz were noted with LNAC use. The percentage of patients with at least 50% recovery was 63% and 35% for the combination and single therapy groups, respectively (p = 0.0319).

Keywords::

• Inner ear
• cochlea
• glutathione
• free radicals
• oxidative stress
• antioxidant
• intratympanic dexamethasone
• prednisone

Acknowledgments

This paper was accepted for an oral presentation at the CORLAS Meeting, Bruges, Belgium, September 4–6, 2011.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.