A case of tacrolimus-induced glucose intolerance following renal allografting

Living renal transplantation (Tx) was carried out on a 41-year-old male undergoing hemodialysis for a six-month period because of end-stage renal failure due to chronic glomerulonephritis. Tacrolimus (FK 506) was used as one of immunosuppressants. The graft worked immediately after Tx. However, his blood sugar level rose extremely high and use of insulin (IS) was required. At the second postoperative day, 0.3 mg/kg/day of FK506 was administered and the trough level (TL) was as high as 65 ng/ml. The serum IS level decreased from the pre-Tx value of 22 microU/ml to 12 microU/ml. With decrease in the dose of FK506, the TL was normalized, and the dose of IS could be decreased. FK506 has been reported to inhibit IS secretion. Therefore, we must be careful to evaluate the blood glucose level in the use of FK506 for patients with poor glucose tolerance.