Japanese study of FK 506 on kidney transplantation: 2. Follow-up study of FK 506-treated patients.

Thirty-seven primary renal transplant patients were enrolled in the early phase II study on kidney transplantation. All grafts survived during the follow-up period. However, 10 of the 37 patients were changed from FK 506 to conventional drugs, and 3 were treated concomitantly with azathioprine (AZA) or mizoribine (MZR) in the 3-month period of observation. After 3 months posttransplantation, an additional 10 patients were treated continuously with AZA or MZR. In addition, 3 were converted from FK 506 to conventional drugs. No additional conversion was observed after 4 months. Trough level monitoring was effective enough to regulate the FK 506 dosage. Nephrotoxicity and hyperglycemia were associated with a high trough level of FK 506 (whole blood, > 20 ng/ml).