Severe elevations of FK506 blood concentration due to diarrhea in renal transplant recipients

BACKGROUND: The rate of metabolism in the intestine of oral administered FK506 decreases as FK506 passes on to the lower intestine. In transplant recipients with diarrhea given oral FK506, the main areas for absorption of FK506 shift to the lower intestine, where the ability to metabolize FK506 is weaker. Therefore it is considered likely that when FK506 is administered to recipients with diarrhea, the blood concentration of FK506 will be higher. MATERIAL AND METHODS: Twenty recipients experiencing episodes of diarrhea were investigated to determine the trough level of FK506 and the time required for the FK506 trough level to return to the level that obtained before diarrhea. AUC0-4h and Cmax of FK506 were investigated in eight recipients. In cases with severe diarrhea, the daily fluctuations of FK506 blood concentration were also investigated. RESULT: The FK506 trough level (p < 0.0001), AUC (p = 0.0173), and Cmax (p = 0.0173) were found to be significantly higher during episodes of diarrhea. In almost all cases, it took between 2 and 4 wk for the elevated FK506 trough level to return to its previous level following a bout of diarrhea. In the daily fluctuations of FK506 concentration, Tmax was prolonged. In some cases, the concentration was highest just before administration of FK506, when it should have been at trough level. CONCLUSIONS: Diarrhea caused significant elevations of trough level, AUC0-4h and Cmax of FK506, and the prolongation of Tmax in renal transplant recipients administered FK506.     

Glucose metabolism in liver transplant recipients treated with FK 506 or cyclosporin in the European multicentre study

Abstract From September 1990 to January 1992, 545 liver transplant patients were randomised to treatment with either FK 506 and prednisolone or a conventional cyclosporin-based immunosuppressive regimen (CBIR). Eight European centres participated in the study. Adverse events were reported as defined by each centre. Hyperglycaemia was reported as an adverse event in 30.7% of patients receiving FK 506 compared with 20.5% in the CBIR group ( P < 0.01). Diabetes mellitus was reported in 17.2% of patients treated with FK 506 and 9.5% of CBIR-treated patients ( P < 0.05). Treatment with insulin was required in 12.0% of patients in the DK 506 treatment group and in 5% in the CBIR group at 6 months. Initially, higher doses of FK 506 were used. During the study, the protocol was changed to allow a lower dose of FK 506. When the early and late cohorts of patients were compared, the incidence of diabetes mellitus fell from 23.9% to 10.5% in FK 506-treated patients but remained relatively constant in the CBIR group (10.4% to 8.7%). The median cumulative doses of i.v. and p. o. corticosteroids were significantly greater in the CBIR group. Thus, in the overall series, the incidence of diabetes mellitus was significantly greater in the FK 506 group as compared with the CBIR group. However, when a lower FK 506 dose was used during the second half of the study, the difference in the incidence of diabetes mellitus disappeared.     

肾移植受者应用他克莫司治疗窗浓度的探讨

目的　寻求适合国人肾移植受者他克莫司 (FK5 0 6 )理想治疗窗浓度范围。方法　应用微粒子酶免疫分析法测定 5 8例肾移植患者口服FK5 0 6后 12h的血药谷浓度 ,并观察排斥反应的发生及药物的肾毒性。结果　FK5 0 6的血药浓度 ,术后 1个月为 (13.0± 2 .1) μg/L ,2～ 3个月为 (9.4±1.6 ) μg/L ,3个月以后为 (6 .5± 1.3) μg/L ,比较各时期全血FK5 0 6谷浓度 ,差异均有极显著性 (P <0 .0 1) ;术后发生急性排斥反应 3例次 ,肾毒性 4例次。结论　FK5 0 6具有良好的免疫抑制效果 ,其治疗窗浓度范围 ,术后第 1个月为 11～ 15 μg/L ,第 2～ 3个月为 8～ 11μg/L ;第 3个月后为 5～ 8μg/L ,此浓度范围既能达到满意的免疫抑制效果 ,又能减少FK5 0 6的肾毒性     

Conversion from cyclosporine to FK506 in adult liver transplant recipients: a combined North American and European experience

BACKGROUND: Although cyclosporine (CsA) made clinical liver transplantation possible, side effects and development of rejection have limited its use. In some patients, conversion to tacrolimus has been necessary to abrogate side effects and to preserve allograft function. METHODS: The results of conversion from CsA to tacrolimus were studied retrospectively in 94 liver allograft recipients from a North American and a European transplant center (Duke University Medical Center, Durham, NC, and Hopital Beaujon, Clichy, France). RESULTS: Forty-seven of 94 patients (50%) were converted for steroid-resistant acute rejection. Conversion was successful in 91% of these patients, whereas 9% of patients developed chronic rejection. A further nine patients were converted for chronic allograft rejection with positive results in eight of nine grafts. Mean serum bilirubin in these nine patients was 8.7 mg/dl before conversion and 2.1 mg/dl 6 months after conversion (P=0.02). Nine patients were converted due to inability to wean steroid. Of these, six patients remains steroid free 1 year after conversion. Twenty-three patients (24%) were converted for nephrotoxicity with a reduction in serum creatinine from 167+/-36 mmol/L to 119+/-28 mmol/L 1 year after conversion (P=0.006). Eight of 11 patients converted for neurotoxicity improved after conversion. Conversion to tacrolimus had no effect on seizure frequency or memory loss. CONCLUSIONS: These results suggest that conversion to tacrolimus from CsA is an appropriate paradigm for graft rescue and treatment of a variety of side effects after liver transplant. However, some situations such as memory loss and hypertension may require other strategies.