Search

Background: Despite a decreased incidence of acute rejection and early renal allograft loss due to calcineurin inhibitors (CNIs) in transplant recipients, nephrotoxicity associated with long-term CNI use remains an important issue. This study evaluated whether a CNI-free regimen, including sirolimus, mycophenolate mofetil, corticosteroids, and anti-interleukin-2 receptor antibody induction, results in improved long-term renal function., Methods: This open-label, randomized, parallel group, comparative study in primary de novo renal transplant recipients was planned for 48 months but terminated early because of high acute rejection rates in the sirolimus arm., Results: Enrollment was stopped after ≈12 months, with 475 transplanted patients randomized (2:1) to sirolimus (n=314) or cyclosporine A (CsA) treatment (n=161). Mean length of follow-up after transplantation was 190 days; this article focuses on available data through 6 months. Mean±SD on-therapy Nankivell-calculated glomerular filtration rate was not significantly different between the sirolimus (69.1±18.7 mL/min) and CsA (66.0±15.2 mL/min) treatment groups. Occurrence and length of delayed graft function was not significantly different between groups. Patients in the sirolimus group experienced numerically lower survival rates (96.9% vs. 99.4%; P=0.14), with nine deaths reported with sirolimus and one with CsA; higher rates of biopsy-confirmed acute rejection (21.4% vs. 6.1%; P<0.001); and higher rates of discontinuations due to adverse events (17.4% vs. 6.8%; P=0.001)., Conclusion: A sirolimus-based, CNI-free immunosuppressive regimen, when used with mycophenolate mofetil, corticosteroids, and anti-interleukin-2 receptor antibody induction, was associated with high rates of biopsy-confirmed acute rejection compared with CsA-based immunosuppression and is not recommended.

Background: The efficacy and safety of sirolimus (SRL) plus tacrolimus (TAC) versus SRL plus cyclosporine (CsA) were compared in high-risk renal allograft recipients., Methods: Evaluable patients (448) were randomly assigned (1:1) before transplant to receive SRL+TAC or SRL+CsA with corticosteroids. Eligible patients were black and/or repeat transplant recipients, and/or those with high titer of panel-reactive antibodies., Results: Demographics were similar between groups. Both treatments demonstrated equivalent efficacy of the composite endpoint at 12 months with efficacy failure rates of 21.9% vs. 23.2% (SRL+TAC vs. SRL+CsA, respectively, 95% CI -10.0 to 7.1, P=0.737). Biopsy-confirmed acute rejection rate (13.8% vs. 17.4%) and graft survival rate (89.7% vs. 90.2%) were similar (SRL+TAC vs. SRL+CsA, respectively). In evaluable patients (received at least 1 dose of study drug), renal function (calculated Nankivell glomerular filtration rate) was not superior in SRL+TAC versus SRL+CsA (54.5 vs. 52.6 mL/min, P=0.466); however, in on-therapy patients, glomerular filtration rate was significantly higher in SRL+TAC at most time points. At 12 months, there were no significant differences in rates of death, discontinuation because of adverse events, hypercholesterolemia, hyperlipemia, or proteinuria. Diarrhea and herpes simplex infections occurred significantly more often in SRL+TAC patients. Hypertension, cardiomegaly, increased creatinine, overdose (primarily calcineurin inhibitor toxicity), acne, urinary tract disorders, lymphocele, and ovarian cysts occurred significantly more often in SRL+CsA patients., Conclusions: This study demonstrated that SRL-based therapy was efficacious in high-risk renal allograft recipients in the first year after transplant, providing equivalent efficacy with CsA or TAC, similar graft survival, low biopsy-confirmed acute rejection rates, excellent renal function, and an acceptable safety profile.

Background: The metabolism of tacrolimus is influenced by several medications when they are given concurrently. We report the interaction between tacrolimus and chloramphenicol in a renal transplant recipient., Methods: An adolescent with vancomycin-resistant Enterococcus was given standard doses of chloramphenicol. Tacrolimus trough levels increased, and the dose was adjusted to maintain the target trough level. Pharmacokinetic studies were obtained during chloramphenicol administration and 14 days after its discontinuation., Results: Toxic levels of tacrolimus were seen on the second day of chloramphenicol administration, requiring an 83% reduction in the tacrolimus dose. The dose-adjusted area under the curve value for tacrolimus was 7.5-fold greater while the patient was on chloramphenicol. These data are consistent with inhibition of tacrolimus clearance by chloramphenicol, Conclusions: Chloramphenicol interferes with tacrolimus metabolism. Careful monitoring of tacrolimus trough levels during concomitant chloramphenicol therapy is recommended to avoid toxicity.