Pharmacokinetics of tacrolimus (FK506) in paediatric liver transplant recipients
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The pharmacokinetics of intravenous and oral tacrolimus was assessed in paediatric liver transplant patients at two centers in Europe. Sixteen patients, age 0.7 to 13 years, participated in the study; 12 patients were evaluable for intravenous pharmacokinetics, and 16 for oral. Intravenous tacrolimus was given as a continuous 24 h infusion (mean 0.037±0.013 mg/kg/day), and oral tacrolimus was given in 2 doses per day (mean 0.152±0.015 mg/kg). Whole blood samples for the intravenous pharmacokinetic profile were taken before initiation of the first infusion, 4, 8, 12 and 24 h post-infusion, and every 24 h thereafter until intravenous administration was discontinued. During the 12 h wash-out period between intravenous and oral administration, samples were taken every 3 h. Samples for the oral pharmacokinetic profile were taken immediately before the first oral dose and 0.5, 0.75, 1, 2, 2.5, 3, 4, 6, 8, 10 and 12 h post-administration. Non-compartmental procedures were used to characterise the pharmacokinetic parameters. Mean estimates for clearance and terminal half-life were 2.3±1.2 ml/min/kg and 11.5±3.8 h, respectively, following intravenous tacrolimus. The mean bioavailability of oral tacrolimus was 25±20%. A strong correlation was observed between AUC and trough whole blood levels of tacrolimus (r=0.90). The clearance was approximately 2-fold higher than that previously observed in adults; this could explain the higher dosage requirements in children.
KeywordsTacrolimus paediatric pharmacokinetics pharmacokinetics
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- 7.Kobayashi M., Tamura K., Katayama N. et al. (1991): FK 506 assay past and present characteristics of FK 506 ELISA. Transplant. Proc., 3, 2725–2729.Google Scholar
- 8.Heinzel G., Woloszczak R., Thomann P. et al. (1993): TopFit: 2.0; pharmacokinetic and pharmacodynamic data analysis system for the PC. Berlin: Gustav Fischer. ISBN 3-437-11486-7.Google Scholar