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Mycophenolate mofetil reduces alveolar inflammation, acute rejection and graft loss due to bronchiolitis obliterans syndrome after lung transplantation. Speich Rudolf,Schneider Silvia,Hofer Markus,Irani Sarosh,Vogt Peter,Weder Walter,Boehler Annette Pulmonary pharmacology & therapeutics BACKGROUND:Bronchiolitis obliterans syndrome (BOS) is still the main complication after lung transplantation. Besides other improvements in post-operative management, newer immunosuppressive regimens might decrease the devastating sequelae of this complication. METHODS:We compared the prospectively collected data of lung transplant recipients treated either with azathioprine (AZA; n = 48) or mycophenolate mofetil (MMF; n = 108), who underwent regular monthly surveillance bronchoscopies for at least 6 post-operative months. RESULTS:Patients on MMF had significantly fewer acute (P < 0.001) and recurrent (P < 0.001), as well as less severe rejection episodes (P = 0.01). In addition, MMF significantly reduced the number of alveolar lymphocytes, eosinophils and neutrophils (P < 0.001), and decreased the hemosiderin score reflecting non-specific alveolar-capillary damage (P < 0.001). Although there was no change in the three stages of BOS, there was a trend towards improved survival (P = 0.062) and a significant decrease in graft loss due to BOS (P = 0.049) in patients receiving MMF. CONCLUSIONS:Immunosuppression with MMF significantly decreased the incidence, severity and recurrence of acute rejection episodes in lung transplant recipients. Parameters of alveolar inflammation and alveolar-capillary damage were also decreased. As a potential consequence, MMF significantly reduced graft loss due to BOS and tended to improve overall survival in these patients. 10.1016/j.pupt.2010.04.004
Limited sampling strategy for predicting area under the concentration-time curve of mycophenolic acid in adult lung transplant recipients. Ting Lillian S L,Partovi Nilufar,Levy Robert D,Riggs K Wayne,Ensom Mary H H Pharmacotherapy STUDY OBJECTIVE:To develop limited sampling strategies for estimation of mycophenolic acid exposure (by determining area under the concentration-time curve [AUC]) in lung transplant recipients by using sampling times within 2 hours after drug administration and a maximum of three plasma samples. DESIGN:Prospective, open-label clinical study. SETTING:Lung transplant clinic in Vancouver, British Columbia, Canada. PATIENTS:Nineteen adult (mean age 48.3 yrs) lung transplant recipients who were receiving mycophenolate mofetil therapy along with cyclosporine (9 patients) or tacrolimus (10 patients). INTERVENTION:Eleven blood samples were collected from each of the 19 patients over 12 hours: immediately before (0 hr) and 0.3, 0.6, 1, 1.5, 2, 4, 6, 8, 10, and 12 hours after administration of mycophenolate mofetil. MEASUREMENTS AND MAIN RESULTS:Mycophenolic acid levels in plasma were determined by a high-performance liquid chromatography-ultraviolet detection method. The 19 patients were randomly divided into index (10 patients) and validation (9 patients) groups. Limited sampling strategies were developed with multiple regression analysis by using data from the index group. Data from the validation group were used to test each strategy. Bias and precision of each limited sampling strategy were determined by calculating the mean prediction error and the root mean square error, respectively. The correlation between AUC and single concentrations was generally poor (r2= 0.18-0.73). Two single-concentration strategies, eight two-concentration strategies, and eight three-concentration strategies matched our criteria. However, the best overall limited sampling strategies (and their predictive performance) were the following: log AUC = 0.241 log C0 + 0.406 log C2 + 1.140 (bias -5.82%, precision 5.97%, r2= 0.828) and log AUC = 0.202 log C0 + 0.411 log C1.5 + 1.09 (bias -5.71%, precision 6.94%, r2= 0.791), where Cx is mycophenolic acid concentration at time x hours. CONCLUSION:Two-concentration limited sampling strategies provided minimally biased and highly precise estimation of mycophenolic acid AUC in lung transplant recipients. These optimal and most clinically feasible limited sampling strategies are based collectively on the number of blood samples required, r2 value, bias, and precision. 10.1592/phco.26.9.1232
Limited Sampling Strategy for the Estimation of Mycophenolic Acid and its Acyl Glucuronide Metabolite Area under the Concentration-Time Curve in Japanese Lung Transplant Recipients. Tanaka Masaki,Kikuchi Masafumi,Takasaki Shinya,Hirasawa Tensei,Sigeta Kensuke,Noda Aoi,Akiba Miki,Matsuda Yasushi,Oishi Hisashi,Sado Tetsu,Noda Masafumi,Okada Yoshinori,Mano Nariyasu,Yamaguchi Hiroaki Journal of pharmacy & pharmaceutical sciences : a publication of the Canadian Society for Pharmaceutical Sciences, Societe canadienne des sciences pharmaceutiques PURPOSE:The dose of mycophenolate mofetil (MMF) used to prevent rejection after lung transplantation is often adjusted based on the 12-hour area under the concentration-time curve (AUC0-12) of mycophenolic acid (MPA). A limited sampling strategy (LSS) is useful to define the pharmacokinetic (PK) profiles of MPA and mycophenolic acid acyl glucuronide (AcMPAG). Therefore, this study aimed to design a LSS based on multiple linear regression for estimating the AUC0-12 of MPA and AcMPAG at the minimum blood sampling points in Japanese lung transplant patients with concomitant tacrolimus. METHODS:Forty-five lung transplantation recipients were enrolled in a PK study of MPA, mycophenolic acid glucuronide (MPAG), and AcMPAG. The plasma MPA, MPAG, and AcMPAG concentrations were determined just before and at 0.5, 1, 2, 4, 8, and 12 hours after dosing. The AUC0-12 of MPA and AcMPAG was calculated using a linear trapezoidal rule from the plasma concentration of each blood sampling time. LSS was used to develop models for estimated AUC in the model group (n = 23) and was evaluated in the validation group (n = 22). RESULTS:The best three time-point equation was 4.04 + 1.64·C1 + 3.08·C4 + 5.17·C8 for MPA, and -0.13 + 3.01·C1 + 3.51·C4 + 5.74·C8 for AcMPAG. The prediction errors (PE) and the absolute prediction errors (APE) were within the clinically acceptable ± 5% and 15% range, respectively (MPA: PE = 2.00%, APE = 11.66%, AcMPAG: PE = 0.98%, APE = 14.69%). The percentage of estimated AUC0-12 within ± 15% of the observed AUC0-12 was 77.27% for MPA and 81.82% for AcMPAG. CONCLUSION:LSS using three time-point (C1, C4, and C8) provides the most reliable and accurate simultaneous estimation of the AUC0-12 of MPA and AcMPAG in Japanese lung transplant patients. 10.18433/jpps30505