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- Colom, Helena, et al.
(författare)
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Pharmacokinetic modeling of enterohepatic circulation of mycophenolic acid in renal transplant recipients.
- 2014
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Ingår i: Kidney International. - : Elsevier BV. - 1523-1755 .- 0085-2538. ; 85:6, s. 1434-1443
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Tidskriftsartikel (refereegranskat)abstract
- Several factors contribute to mycophenolic acid (MPA) between-patient variability. Here we characterize the metabolic pathways of MPA and quantify the effect of combining genetic polymorphism of multidrug-resistant-associated protein-2, demographics, biochemical covariates, co-medication (cyclosporine (CsA) vs. macrolides), and renal function on MPA, 7-O-MPA-glucuronide (MPAG), and acyl-glucuronide (AcMPAG) disposition, in renal transplant recipients, after mycophenolate mofetil. Complete pharmacokinetic profiles from 56 patients (five occasions) were analyzed. Enterohepatic circulation was modeled by transport of MPAG to the absorption site. This transport significantly decreased with increasing CsA trough concentrations (CtroughCsA). MPAG and AcMPAG plasma clearances significantly decreased with renal function. No significant influence of multidrug-resistant-associated protein-2 C24T single-nucleotide polymorphism was found. The model adequately predicted the increase in MPAG/AcMPAG exposures in CsA and macrolide patients with decreased renal function. This resulted in higher MPA exposures in macrolide patients versus CsA patients, and increased MPA exposures with renal function from 25 to 10 ml/min, in macrolide patients, owing to enhanced MPAG enterohepatic circulation. Lower-percentage enterohepatic circulation occurred with higher CtroughCsA and renal function values. The lack of MPA protein-binding modeling did not permit evaluation of the impact of renal function and CtroughCsA on MPA exposures in CsA patients. Thus, dose tailoring of covariates is recommended for target MPA exposure.Kidney International advance online publication, 8 January 2014; doi:10.1038/ki.2013.517.
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| 2. |
- Grinyo, Josep M., et al.
(författare)
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The pharmacokinetics of mycophenolate mofetil in renal transplant recipients receiving standard-dose or low-dose cyclosporine, low-dose tacrolimus or low-dose sirolimus: the Symphony pharmacokinetic substudy
- 2009
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Ingår i: Nephrology Dialysis Transplantation. - : Oxford University Press (OUP). - 1460-2385 .- 0931-0509. ; 24:7, s. 2269-2276
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Tidskriftsartikel (refereegranskat)abstract
- Methods. A 3-month pharmacokinetic substudy of the prospective, randomized, multicentre, open-label Symphony study was performed. Eighty-three adult renal transplant patients received standard-dose cyclosporine, MMF 2 g/day and corticosteroids, or daclizumab induction, MMF 2 g/day and corticosteroids plus low-dose cyclosporine, low-dose tacrolimus or low-dose sirolimus. The area under the concentration-time curve (AUC(0-12)) of MPA and its metabolites between treatment groups was compared. Pharmacokinetic sampling was performed before MMF administration and at 20, 40, 75 min; 2, 3, 6, 8, 10 and 12 h post-dose on Day 7 and Months 1 and 3. Results. Compared with standard-dose cyclosporine, patients receiving low-dose tacrolimus or low-dose sirolimus had significantly higher AUC(0-12) values for MPA at Day 7 and Month 1 and for free MPA at Day 7, and significantly lower AUC(0-12) values for 7-O-MPA-glucuronide (MPAG) at Month 1 and for acyl-glucuronide at Months 1 and 3 (P < 0.05). AUC(0-12) of MPA and free MPA was significantly greater with low-dose tacrolimus and low-dose sirolimus than with low-dose cyclosporine in the first month (P < 0.05). The ratio of MPA to MPAG exposure was significantly higher in the three low-dose groups than in the standard-dose cyclosporine group (P < 0.05). Conclusions. Standard- and low-dose cyclosporine reduces the exposure of MPA and free MPA compared to low-dose tacrolimus or low-dose sirolimus in patients given the same dose of MMF.
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| 3. |
- Lloberas, Nuria, et al.
(författare)
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Influence of MRP2 on MPA pharmacokinetics in renal transplant recipients-results of the Pharmacogenomic Substudy within the Symphony Study
- 2011
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Ingår i: Nephrology Dialysis Transplantation. - : Oxford University Press (OUP). - 1460-2385 .- 0931-0509. ; 26:11, s. 3784-3793
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Tidskriftsartikel (refereegranskat)abstract
- Background. The aim of this study was to determine the relationship between single-nucleotide polymorphisms (SNPs) in MRP2 genes and mycophenolic acid (MPA) pharmacokinetics in renal transplant recipients of the Symphony Pharmacogenomic substudy. Methods. Sixty-six renal transplant recipients of eight Spanish centres were randomized into four branches of immunosuppressive regimen: low dose of cyclosporine, standard dose of cyclosporine, tacrolimus and sirolimus, all in addition to mycophenolate mofetil and steroids. Fifty-five patients were genotyped for SNPs in MRP2, C24T and C3972T. Pharmacokinetic sampling was done before MPA administration and up to 12 h post-dose at Day 7, 1 month and 3 months post-transplant. Relationships of area under the curve (AUC) of MPA and MPAG plasmasampling with the presence of MRP2 SNPs and with the immunosuppressive regimens were studied. Results. At steady-state conditions, MPA-reduced exposure was observed in C24T variant allele in MRP2 (CC: 68.73 +/- 6.78; *T: 48.12 +/- 4.90, P = 0.023); no significant differences linked to C3972T SNP were observed. Taking into account groups of treatment, lower MPA AUC in variant allele of C24T was only found under macrolides treatment with statistically significant differences at Month 3 (Tac and SRL, CC: 86.52 +/- 10.98 versus *T: 41.99 +/- 4.82, P = 0.001; CsA, CC: 52.31 +/- 5.30 versus *T: 54.24 +/- 8.30, P = 0.772); for C3972T, the same tendency was found but differences at steady state did not reach statistical significance. Conclusions. Renal transplant recipients T carriers of C24T MRP2 with macrolides treatment were associated with reduced MPA AUC in steady-state conditions. Patients treated
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