|
|
||||||||
Sign In to gain access to subscriptions and/or personal tools. |
|||||||||
DRUG METABOLISM |
From the School of Pharmacy, University of Southern California, Los Angeles (Dr. Zheng, Dr. Burckart); School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (Dr. Zeevi, Dr. McCurry, Dr. Griffith, Dr. Webber, Ms. Ristich, Dr. Dauber, Dr. Iacono, Mr. Grgurich, Ms. Zaldonis, Mr. McDade); and Department of Pharmacology, St. Jude Children's Research Hospital, Memphis, Tennessee (Dr. Schuetz, Dr. Lamba, Dr. Zhang).
Tacrolimus is a potent immunosuppressive agent used in lung transplantation and is a substrate for both P-glycoprotein (P-gp, encoded by the gene MDR1) and cytochrome (CYP) P4503A. A previous study by the authors identified a correlation between the tacrolimus blood level per dose with CYP3A5 and MDR1 gene polymorphisms in pediatric heart transplant patients. The objective of this study was to confirm the influence of these polymorphisms on tacrolimus dosing in adult lung transplant patients. Adult lung transplant patients who had been followed for at least 1 year after lung transplantation were studied. Tacrolimus blood level (ng/mL) per dose (mg/day) at 1, 3, 6, 9, and 12 months after transplantation was calculated as [L/D]. DNA was extracted from blood. MDR1 3435 CC, CT, and TT; MDR1 2677 GG, GT, and TT; and CYP3A5*.1 (expressor) and *3 (nonexpressor) genotypes were determined by PCR amplification, direct sequencing, and sequence evaluation. Eighty-three patients were studied. At 1, 3, 6, 9, and 12 months after the transplant, a significant difference in [L/D] was found between the CYP3A5 expressor versus nonexpressor genotypes (mean ± SD of 1.49 ± 0.88 vs. 3.11 ± 4.27, p = 0.01; 1.23 ± 0.82 vs. 3.44 ± 8.97, p = 0.05; 1.32 ± 0.96 vs. 3.81 ± 6.66, p = 0.005; 0.95 ± 1.19 vs. 3.74 ± 5.98, p = 0.0015; and 0.45 ± 0.2 vs. 3.76 ± 6.75, p = 0.0001, respectively). MDR1 G2677T and C3435T genotypes had only minimal effects on [L/D] at 1 and 3 months after transplantation. This study confirms the relationship of CYP3A5 polymorphisms to tacrolimus dosing in organ transplant patients. CYP3A5 expressor genotypes required a larger tacrolimus dose to achieve the same blood levels than the CYP3A5 nonexpressors at all time points during the first posttransplant year. This was not uniformly true for MDR1. The authors therefore conclude that tacrolimus dosing in adult lung transplant patients is associated with CYP3A5 gene polymorphisms.
Key Words: P-glycoprotein MDR1 CYP3A5 polymorphism transplantation tacrolimus dosing
Address for reprints: Gilbert J. Burckart, PharmD, University of Southern California, 1985 Zonal Avenue, PSC-100, Los Angeles, CA 90033.
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
This article has been cited by other articles:
![]() |
S. Liu, P. M. Beringer, L. Hidayat, A. P. Rao, S. Louie, G. J. Burckart, and B. Shapiro Probenecid, but Not Cystic Fibrosis, Alters the Total and Renal Clearance of Fexofenadine J. Clin. Pharmacol., August 1, 2008; 48(8): 957 - 965. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. J. Gardiner and E. J. Begg Pharmacogenetics, Drug-Metabolizing Enzymes, and Clinical Practice Pharmacol. Rev., September 1, 2006; 58(3): 521 - 590. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Warnecke, M. Avsar, T. Steinkamp, R. Reinhard, J. Niedermeyer, A. R. Simon, A. Haverich, and M. Struber Tacrolimus versus cyclosporine induction therapy in pulmonary transplantation in miniature swine Eur. J. Cardiothorac. Surg., September 1, 2005; 28(3): 454 - 460. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. K. Kamdem, F. Streit, U. M. Zanger, J. Brockmoller, M. Oellerich, V. W. Armstrong, and L. Wojnowski Contribution of CYP3A5 to the in Vitro Hepatic Clearance of Tacrolimus Clin. Chem., August 1, 2005; 51(8): 1374 - 1381. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Zheng, E. Schuetz, A. Zeevi, J. Zhang, K. McCurry, S. Webber, A. Iacono, J. Lamba, and G. J. Burckart Sequential Analysis of Tacrolimus Dosing in Adult Lung Transplant Patients With ABCB1 Haplotypes J. Clin. Pharmacol., April 1, 2005; 45(4): 404 - 410. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |