The use of glucocorticoids for secondary (salvage/rescue) therapy of idiopathic sudden hearing loss (ISSHL), including controlled and uncontrolled studies with intratympanic injections or continuous, catheter mediated applications, were evaluated by means of a meta-analysis in an attempt to define optimal local drug delivery protocols for ISSHL.
A total of 30 studies with 33 treatment groups between January 2000 and June 2014 were selected based on sufficiently detailed description of application protocols. Cochlear drug levels were calculated by a validated computer model of drug dispersion in the inner ear fluids based on the concentration and volume of glucocorticoids applied, the time drug remained in the middle ear, and on the specific timing of injections. Various factors were compared with hearing outcome, including baseline data, individual parameters of the application protocols, calculated peak concentration (C max), and total dose (area under the curve, AUC).
There was no dependence of hearing outcome on individual parameters of the application protocol, C max or AUC. Hearing gain and final hearing thresholds were independent of treatment delay.
Based on the available data from uncontrolled and controlled randomized and non-randomized studies no clear recommendation can be made so far for a specific application protocol for either primary or secondary (salvage) intratympanic steroid treatment in patients with ISSHL. For meta-analyses, change in pure tone average (PTA) may not be an adequate outcome parameter to assess effectiveness of the intervention especially with inhomogeneity of patient populations. Final PTA might provide a better outcome parameter.
*Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Germany
†Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri
Address correspondence and reprint requests to Stefan K. Plontke, Prof. Dr., med., Department of Otorhinolaryngology–Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, D-06120 Halle (Saale), Germany; E-mail: Stefan.Plontke@uk-halle.de
Funding: This work was supported by BMBF 01KG1427 (S.K.P.) and by NIH/NIDCD grant DC001368 (A.N.S.).
Disclosures: S.K.P. is a consultant for Otonomy, Inc., San Diego, USA and chief of the scientific advisory board of AudioCure Pharma GmbH, Berlin, Germany.
A.N.S. is a member of the scientific advisory board of Otonomy, Inc. and may receive income based on equity holdings. This work was not sponsored by any of the above companies.