Sudden hearing loss associated with tacrolimus in a kidney-pancreas allograft recipient

A 38-year-old woman with type 1 diabetes underwent kidney-pancreas transpla ntation. Her postoperative course was complicated due to recurrent acute gr aft rejections and pancreatitis. After initial immunosuppression with micro emulsion cyclosporine, mycophenolate, mofetil, and prednisone with muromona b-CD3 induction, cyclosporine was switched to tacrolimus on day 44. The ini tial dosage was 5 mg twice/day but it was gradually increased to 10 mg twic e/day, aiming at 15-20 ng/ml. On day 17 of tacrolimus therapy the woman dev eloped sudden hearing loss with tinnitus. The serum tacrolimus level was 28 .3 ng/ml (therapeutic range 10-20 ng/ml) on day 20 of tacrolimus therapy, a nd peaked at 34.9 ng/ml on day 28. Two audiograms performed on days 28 and 29 confirmed bilateral hearing loss of 80% for speech perception, character ized as mild to moderate sensorineural hearing loss with speech reception t hreshold of 35 dB (normal < 20 dB) in both ears. The tacrolimus dosage was gradually reduced to 6 mg twice/day by day 36, with drug level 9.7 ng/ml, a fter which her hearing gradually recovered.