Effects of a dexamethasone-releasing implant on cochleae: A functional, morphological and pharmacokinetic study

Long-Term in vivo Release Profile of Dexamethasone-Loaded Silicone Rods Implanted Into the Cochlea of Guinea Pigs

“…In the study of Bas et al (45) for the implanted 1% loaded rods, the protective effect on hearing thresholds was unchanged through the end of the 13 week observation period. In the study of Liu et al (55) using a 2% load, protection of hearing thresholds appeared to start to deteriorate at 16 weeks after implantation although ABR thresholds were still significantly different between treatment and control group after 24 weeks. Stathopoulos et al (42) found no difference between two guinea pig groups implanted with either a control electrode dummy or a dexamethasone-eluting dummy in terms of spiral ganglia density, organ of Corti integrity, or fibrosis and ossification at 12 weeks after implantation.…”

“…The same group performed a study conducting physiological tests and histological examination after implanting the 2% dexamethasone loaded rods in guinea pigs in comparison to animals implanted with silicone rods without incorporated dexamethasone (55). Based on the data of the current study and total drug load of the rods used by Liu et al (55), it could be speculated that the rod loading used in their study led to perilymph drug concentrations between 50 and 100 ng/ml during the steady state phase (Figures 4A, 6). Implanted animals from both groups displayed an initial ABR threshold shift after implantation.…”

Hearing Changes After Intratympanically Applied Steroids for Primary Therapy of Sudden Hearing Loss: A Meta-analysis Using Mathematical Simulations of Drug Delivery Protocols

“…In this study an inner ear dexamethasone steady state concentration of 0.1 μg/ml was achieved in the scala tympani (15,16). In another study using a similar dummy and EIT animal model a down regulation of TNF-a in cochlear tissue was shown in comparison to control group (17). …”

Electric and Acoustic Stimulation in Cochlear Implant Recipients with Hearing Preservation

“…A variety of studies have shown that hearing loss induced by implant insertion trauma could be reduced with drugeluting materials placed during implantation, catheters for infusion, or drug-eluting devices themselves. [53][54][55][56][57][58][59][60][61] The efficacy and feasibility of such a drug-eluting system also has been demonstrated in humans. 62 Regardless of the method, corticosteroids reduce inflammatory processes caused by electrode insertion resulting in better preservation of cochlear structures, 63 and stabilization of hearing levels.…”