Population pharmacokinetics models of sirolimus in renal transplant patients: A systematic review.

OBJECTIVE

Sirolimus is used in the immunosuppressive therapeutic treatment  of kidney transplant patients. The high pharmacokinetic variability of sirolimus  makes pharmacokinetic monitoring and dosage individualization of  mmunosuppressive therapy a key process to achieve better efficacy results.  The availability of a population pharmacokinetic model can be used to provide  better pharmacokinetic adjustment of plasma concentrations of sirolimus and  thus achieve greater clinical benefit.

METHOD: We conducted a systematic review of the literature available in the  Medline, Embase, and Scopus databases to identify and subsequently analyze  population pharmacokinetic models of orally administered sirolimus in adult  patients after kidney transplant. The descriptors used MeSH were kidney  transplantation, pharmacokinetics, and sirolimus. The following variables from  the selected studies were assessed: study population, immunosuppressive  treatment, blood sampling times, covariates analyzed, type of pharmacokinetic  model, computer software used, estimated pharmacokinetic  parameters, interindividual variability of pharmacokinetic parameters, residual  variability and mathematical equations of the pharmacokinetic model.

RESULTS

A total of 548 results were obtained, excluding 175 records that were  identified in more than one database. Finally, seven articles that  et  the inclusion criteria were selected. Most of the pharmacokinetic models found fit a two-compartment model. The interindividual variability of sirolimus  was explained by covariates such as age, weight, liver function, cyclosporine exposure and dose, sirolimus doses, CYP3A5 genetic  olymorphisms, serum creatinine, and concomitant treatment.

CONCLUSIONS

The two-compartment model was the pharmacokinetic model of  choice in most of the selected studies. The interindividual variability of the  pharmacokinetic parameters of sirolimus is explained by demographic, clinical,  genetic, and biochemical variables. The availability of pharmacokinetic models  of sirolimus can assist in optimizing therapy in patients after kidney transplant.