title: Pharmacokinetic variability of sirolimus in Taiwanese renal transplant recipients.
abstract: To evaluate the pharmacokinetic variability of sirolimus (Rapamycin, SRL) in our renal transplant (RTx) recipients, dose-normalized trough concentration (C(0)) of SRL, and their intrasubject coefficients of variation (%CV) were analyzed. Thirty-eight patients were enrolled in regimens containing SRL. Concomitant immunosuppression included steroids (n = 38), cyclosporine (n = 33), tacrolimus (n = 3), and mycophenolate mofetil (n = 7). The mean dose-normalized C(0) was 2.13 +/- 0.91 ng/mL/mg. The intrasubject %CV of the dose-normalized C(0) ranged from 14% to 88% and averaged 42% in our series. The mean dose-normalized C(0) of SRL in our RTx recipients was much lower than that reported in Phase III trials. The intrasubject variation of dose-normalized C(0), even after administrating SRL for 6 months, could still be quite prominent. Thus, we suggest that, to maintain adequate therapeutic concentrations, periodic (monthly or bimonthly) SRL C(0) measurement is necessary in Taiwanese (Oriental) patients receiving SRL.
authors.affiliation: Department of Urology, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan. scchueh@ha.mc.ntu.edu.tw
authors.forename: S-C J
authors.initials: SC
authors.lastname: Chueh
authors.forename: S-M
authors.initials: SM
authors.lastname: Wang
authors.forename: M-K
authors.initials: MK
authors.lastname: Lai
authors.forename: J
authors.initials: J
authors.lastname: Chen
mesh_terms: D016572:Cyclosporine / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D006801:Humans; D007166:Immunosuppressive Agents / Q000145:classification / Q000493:pharmacokinetics / Q000627:therapeutic use; D016030:Kidney Transplantation / Q000276:immunology* / Q000502:physiology; D012189:Retrospective Studies; D020123:Sirolimus / Q000493:pharmacokinetics* / Q000627:therapeutic use; D016559:Tacrolimus / Q000627:therapeutic use; D013624:Taiwan
chemical_list: D007166:Immunosuppressive Agents; D016572:Cyclosporine; D020123:Sirolimus; D016559:Tacrolimus