Evaluation of prednisolone and prednisolone sodium succinate concentrations in human plasma and inner ear perilymph during cochlear implantation 24 h after intratympanic injection.

BACKGROUND
The use of intratympanic (IT) steroids has drastically increased over the past 10-15 years to manage many otological pathologies.


OBJECTIVES
This study aimed to compare the concentrations of prednisolone and prednisolone sodium succinate (SS) in the plasma and inner ear perilymph of participants who underwent cochlear implantation 24 h after IT injection.


MATERIALS AND METHODS
It was a prospective comparative randomized study. Twenty participants received an IT injection of prednisolone SS ∼24 h before the cochlear implantation. The other five participants received an IT saline injection and represented the control group. Perilymph and blood were sampled during the cochlear implantation surgery.


RESULTS
Both prednisolone and prednisolone SS were still present in perilymph ∼24 h after the IT administration. Only prednisolone was present in the blood plasma of seven participants (35%).


CONCLUSION
IT injection of prednisolone SS resulted in high perilymph concentrations of prednisolone and prednisolone SS, which could stay in the perilymph for at least 24 h. Using a mini-endoscope during the IT injection may effectively detect barriers infront of the round window membrane, increasing the drug concentration in the inner ear.


SIGNIFICANCE
IT injection is an effective method for delivering prednisolone to the inner ear.