Objective To evaluate the population
pharmacokinetic character of orally tacrolimus(FK506) from routine drug monitoring data
after renal transplantation and to provide the evidence of the schedule of individual dosage. Methods Routine monitoring FK506 whole blood concentration data were collected retrospectively and estimated by
nonlinear mixed effect model(NONMEM) program. There were 88 patients and 366 concentration data and built the FK506 population database. The fixed effect factors, such as gender, age, weight ,period after operation, and so on. The individual dosage schedule was also designed using the population
pharmacokinetic results. Results The steady-state model was fitted in the routine monitoring drug concentration and the POSTHOC sub-program was used to calculate the data model. The statistic analysis indicated that the dosage, creatinine and blood urea nitrogen had apparent influence on the result. Conclusion The veracity of the model was good and an good fitness was derived from the population model that should provide a new approach for cli- nical adjustment of the oral FK506 dosage.