100
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      A Randomized Pharmacokinetic Study of Generic Tacrolimus Versus Reference Tacrolimus in Kidney Transplant Recipients

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Pharmacokinetic analyses comparing generic tacrolimus preparations versus the reference drug in kidney transplant patients are lacking. A prospective, multicenter, open-label, randomized, two-period (14 days per period), two-sequence, crossover and steady-state pharmacokinetic study was undertaken to compare twice-daily generic tacrolimus (Sandoz) versus reference tacrolimus (Prograf®) in stable renal transplant patients. AUC 0–12h and peak concentration (C max) were calculated from 12 h pharmacokinetic profiles at the end of each period (days 14 and 28). Of 71 patients enrolled, 68 provided evaluable pharmacokinetic data. The ratios of geometric means were 1.02 (90% CI 97–108%, p = 0.486) for AUC 0–12h and 1.09 (90% CI 101–118%, p = 0.057) for C max. Mean (SD) C 0 was 7.3(1.8) ng/mL for generic tacrolimus versus 7.0(2.1) ng/mL for reference tacrolimus based on data from days 14 and 28. Correlations between 12 h trough levels and AUC were r = 0.917 for generic tacrolimus and r = 0.887 for reference drug at day 28. These data indicate that generic tacrolimus (Sandoz) has a similar pharmacokinetic profile to the reference drug and is bioequivalent in kidney transplant recipients according to US Food and Drug Administration and European Medicines Agency guidelines.

          Related collections

          Most cited references28

          • Record: found
          • Abstract: found
          • Article: not found

          A comparison of the two one-sided tests procedure and the power approach for assessing the equivalence of average bioavailability.

          The statistical test of hypothesis of no difference between the average bioavailabilities of two drug formulations, usually supplemented by an assessment of what the power of the statistical test would have been if the true averages had been inequivalent, continues to be used in the statistical analysis of bioavailability/bioequivalence studies. In the present article, this Power Approach (which in practice usually consists of testing the hypothesis of no difference at level 0.05 and requiring an estimated power of 0.80) is compared to another statistical approach, the Two One-Sided Tests Procedure, which leads to the same conclusion as the approach proposed by Westlake based on the usual (shortest) 1-2 alpha confidence interval for the true average difference. It is found that for the specific choice of alpha = 0.05 as the nominal level of the one-sided tests, the two one-sided tests procedure has uniformly superior properties to the power approach in most cases. The only cases where the power approach has superior properties when the true averages are equivalent correspond to cases where the chance of concluding equivalence with the power approach when the true averages are not equivalent exceeds 0.05. With appropriate choice of the nominal level of significance of the one-sided tests, the two one-sided tests procedure always has uniformly superior properties to the power approach. The two one-sided tests procedure is compared to the procedure proposed by Hauck and Anderson.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            High within-patient variability in the clearance of tacrolimus is a risk factor for poor long-term outcome after kidney transplantation.

            We hypothesized that a high within-patient variability in clearance of tacrolimus and mycophenolate mofetil (MMF) would put patients at risk for periods of over- or underimmunosuppression and would thus lead to long-term chronic allograft nephropathy and graft loss after transplantation. From 297 patients transplanted between 1 January 2000 and 31 December 2004, the within-patient variability in clearance was calculated from tacrolimus whole-blood concentrations and mycophenolic acid (MPA) plasma concentrations drawn between 6 and 12 months post-transplantation. As a primary outcome, a composite end point consisting of graft loss, biopsy-proven chronic allograft nephropathy and 'doubling in plasma creatinine concentration in the period between t = 12 months post-transplantation and last follow-up' was used. In the study population of 297 patients, 34 patients reached the primary end point of graft failure. The within-patient variability in the clearance of tacrolimus and three other covariates are significant risk factors for reaching the composite end point of failure [P-values for intraindividual tacrolimus variability = 0.003, biopsy-proven acute rejection (BPAR) = 0.003, recipient age at transplantation = 0.005]. The mean tacrolimus concentration for controls [7.4 (+/- 2.9) ng/mL] and for failures [6.9 (+/- 2.5) ng/mL] was similar. Within-patient variability in the clearance of MPA was not related to reaching the composite end point of failure. This study shows a significant relationship between the high within-patient variability in the clearance of tacrolimus, but not for MPA, and long-term graft failure.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              AUC-guided dosing of tacrolimus prevents progressive systemic overexposure in renal transplant recipients.

              Tacrolimus has a narrow therapeutic window, and bioavailability is known to vary considerably between renal transplant recipients. Most centers still rely on measurement of trough levels, but there are conflicting reports on the correlation between tacrolimus trough levels and systemic exposure, as measured by the area-under-the-concentration-over-time curve (AUC((0-12h))). We developed and validated a two-compartmental population-based pharmacokinetic model with Bayesian estimation of tacrolimus systemic exposure. Subsequently, we used this model to apply prospectively AUC-guided dosing of tacrolimus in 15 consecutive renal transplant recipients. The main objective was to study intrapatient variability in the course of time. Bayesian forecasting with a two-point sampling strategy, a trough level, and a second sample obtained between two and four hours post-dose significantly improved the squared correlation with the AUC((0-12h)) (r(2)= 0.94). Compared with trough level monitoring only, this approach reduced the 95%-prediction interval by 50%. The Bayesian approach proved to be feasible in clinical practice, and provided accurate information about systemic tacrolimus exposure in individual patients. In the AUC-guided dosing cohort the apparent clearance of tacrolimus decreased gradually over time, which was not reflected in corresponding trough levels. This simple, flexible method provides the opportunity to tailor immunosuppression, and should help minimize tacrolimus-related toxicity, such as nephrotoxicity and post-transplant diabetes mellitus.
                Bookmark

                Author and article information

                Journal
                Am J Transplant
                Am. J. Transplant
                ajt
                American Journal of Transplantation
                Blackwell Publishing Inc (Malden, USA )
                1600-6135
                1600-6143
                October 2012
                : 12
                : 10
                : 2825-2831
                Affiliations
                [a ]Division of Nephrology, Section of Transplantation, University of Cincinnati Cincinnati, OH
                [b ]Renal Division, Perelman School of Medicine, University of Pennsylvania, and Department of Pharmacy, Hospital University of Pennsylvania Philadelphia, PA
                [c ]Novartis Pharmaceuticals Corporation East Hanover, NJ
                [d ]Renal Division, Perelman School of Medicine, University of Pennsylvania Philadelphia, PA
                Author notes
                *Corresponding author: Rita R. Alloway, allowarr@ 123456ucmail.uc.edu

                Re-use of this article is permitted in accordance with the Terms and Conditions set out at http://wileyonlinelibrary.com/onlineopen#OnlineOpen_Terms

                Article
                10.1111/j.1600-6143.2012.04174.x
                3472020
                22759200
                677760fa-e558-4f9c-b329-01e8a77ee7fe
                © Copyright 2012 The American Society of Transplantation and the American Society of Transplant Surgeons

                Re-use of this article is permitted in accordance with the Creative Commons Deed, Attribution 2.5, which does not permit commercial exploitation.

                History
                : 15 March 2012
                : 30 April 2012
                : 15 May 2012
                Categories
                Brief Communications

                Transplantation
                pharmacokinetic,generic,kidney transplantation,tacrolimus,hecoria,sandoz
                Transplantation
                pharmacokinetic, generic, kidney transplantation, tacrolimus, hecoria, sandoz

                Comments

                Comment on this article