Sudden Hearing Loss Associated with High Levels of Calcineurin Inhibitors after Liver Transplantation

Hearing impairment in patients after liver transplantation (OLT) has only been reported sporadically. However, potential ototoxic side effects may be related to immunsuppression. We report a se- ries of 5 patients who developed sudden hearing loss after OLT and presented high levels of calcineurin inhibitors at the same time. In 4/5 patients, sudden hearing loss was bilateral. Patientsmain characteristic were very heterogenous (e.g. age, time since OLT, underlying liver disease). Sudden hearing loss occured under high levels of tacrolimus (n=3, mean serum levels at the time of hearing loss: 24 ng/ml) and cyclosporine A (n=2, 343 ng/ml), respectively. Further immunosuppression consisted of prednisolone (n=4) and azathioprine (n=1). There were no other risk factors such as admin- istration of ototoxic drugs. Levels of immunsuppressants were rap- idly corrected after the event. Nevertheless, in 4/5 patients hearing aids (3/4 bilateral) became necessary during follow-up. Further- more, two patients suffer from tinnitus since the hearing loss. In conclusion, high levels of calcineurin-inhibitors after OLT seem to be a risk factor for sudden hearing loss. In most cases, hearing loss was irreversible and resulted in need of a hearing aid. Neuro- toxicity may be a probable mechanism. Further evaluations are necessary to allow a better understanding of the problem.