ABSTRACT
OBJECTIVE To develop a population pharmacokinetic （PPK） model for mycophenolate mofetil active metabolite mycophenolic acid （MPA） in children with primary IgA nephropathy， explore the factors affecting the pharmacokinetic parameters of MPA， and provide a basis for clinical individualized therapy. METHODS Retrospective collection was conducted on 636 concentrations and clinical data from 47 pediatric patients with primary IgA nephropathy. PPK analysis was carried out by using the nonlinear mixed-effects model； the covariates were tested with a stepwise method. Goodness-of-fit plots， Bootstrap and visual predictive check were employed to evaluate the final model. RESULTS The pharmacokinetics of MPA in children with IgA nephropathy in vivo conformed to the first-order absorption and elimination two-compartment model （objective function value of 3 276.31）. Covariate analysis suggested that body weight and albumin （ALB） levels were significant influencing factors on apparent clearance rate and apparent distribution volume. The typical values of PPK parameters of MPA in the final model were as follows： the central room had a distributed volume of 5.79 L， the clearance rate was 4.06 L/h， the volume of peripheral ventricular distribution was 430.93 L， the clearance rate between compartments was 15.40 L/h， the oral absorption rate constant was 1.29 h－1. After verification， most of the predicted corrected observed concentration points were within the 90% confidence interval of the predicted corrected simulated concentration， indicating that the MPA final model had good predictive performance. CONCLUSIONS The PPK model of MPA in children with primary IgA nephropathy is established in this study， identifying body weight and ALB levels are significant factors affecting MPA metabolism.
ABSTRACT
OBJECTIVE To establish a physiologically-based pharmacokinetic （PBPK） model of amikacin in elderly patients with renal insufficiency. METHODS PK-SIM® software was adopted for model building， optimization and simulation. The physical and chemical properties and pharmacokinetic parameters related to amikacin were collected by literature review. The PBPK model on adults was established and extrapolated to the elderly population based on the built-in human model. Data from clinical PK studies were used to optimize and validate the model. The goodness of fit， relative residual， and mean folding error （MFE） were used to evaluate the performance of forecasting. The final model was employed to simulate the exposure of amikacin in the elderly population with renal insufficiency， and the efficacy and safety of commonly used clinical dosing regimens were evaluated， and the recommended regimens were proposed. RESULTS The established PBPK model of amikacin had good prediction performance in both adult and elderly populations， with the absolute mean of relative residual value of 25%； the MFE of peak concentration （cmax） and area under the plasma concentration curve （AUC0－∞） in all simulation occasions ranged ＞0.5-＜2. The simulation results showed that， compared with healthy adults， no significant clinical difference in cmax was observed in the elderly with renal insufficiency at the same dosing regimen， but the trough concentration increased significantly due to accumulation. Prolonging the administration interval of amikacin rather than reducing the dosage was more helpful to ensure the efficacy and to reduce the occurrence of nephrotoxicity. CONCLUSIONS The PBPK model for amikacin is successfully established in the elderly patient with renal insufficiency， and shows good predictive performance.
ABSTRACT
Objective To observe the effect of Jingui Shenqi Wan (JSW) on the content of calcium channel protein CaV1.3 of guinea pigs with ototoxic deafness induced by gentamicin (GM). Methods Forty healthy guinea pigs were randomly divided into normal group, model group and high-, middle-, and low-dose JSW treatment groups. The model group was given intramuscular injection of GM ( 120 mg/kg) per day for 10 continuous days. The high-, middle-, and low-dose JSW treatment groups were given intramuscular injection of GM (120 mg/kg) and intragastric administration of JSW in the dosage of 20.3, 13.5, 6.08 g·kg-1·d-1 respectively per day for 10 days. Immuno histochemistry was used to detect the mean optical density value of CaV1.3 expression in cochlear hair cells. Results There were significant differences of the optical density value of CaV1.3 in cochlear hair cells between the model group and normal group (P<0.01), and between the model group and high-dose JSW treatment group (P<0.05). Conclusion JSW has certain effect on preventing and treating guinea pig with ototoxic deafness induced by GM, thus to protect the hearing function.