Long-Term Influence of CYP3A5, CYP3A4, ABCB1, and NR1I2 Polymorphisms on Tacrolimus Concentration in Chinese Renal Transplant Recipients.

Background: The highly pharmacokinetic variability of tacrolimus makes it difficult to adjust the dose. In the current study, we investigated the influence of gene polymorphisms and other clinical factors on long-term tacrolimus dosing in Chinese renal transplant recipients.

Methods: A total of 276 renal transplant recipients were enrolled.

Association of CYP3A4*18B and CYP3A5*3 polymorphism with cyclosporine-related liver injury in Chinese renal transplant recipients.

Objective: The purpose of this study was to investigate the associations between CYP3A4*18B and CYP3A5*3 polymorphism and cyclosporine-related liver injuries in Chinese renal transplant recipients.

Methods: We genotyped 339 renal transplant recipients treated with a triple immunosuppressive regimen including cyclosporine for CYP3A4*18B and CYP3A5*3 polymorphism using the polymerase chain reaction restriction fragment length polymorphism assay.

Results: The incidence of liver injury in the study population was 36.

In vivo effect of Schisandrin B on cytochrome P450 enzyme activity.

To investigate the possible drug interaction, this study is designed to evaluate the ability of Schisandrin B (Sch B) to modulate cytochrome P450 3A activity (CYP3A) in vivo and to alter the pharmacokinetic profiles of CYP3A substrate (midazolam) in treated rats. Rats were repeated administered with physiological saline (negative control group), ketoconazole (75 mg/kg, positive control group) or varied doses of Sch B (experimental groups) for three consecutive days. Subsequently, changes in hepatic microsomal CYP3A activity and the pharmacokinetic profiles of midazolam and 1'-hydroxy midazolam in plasma were studied to evaluate CYP3A activity.

Association between inosine triphosphate pyrophosphohydrolase deficiency and azathioprine-related adverse drug reactions in the Chinese kidney transplant recipients.

Azathioprine (AZA) is a thiopurine prodrug commonly used in patients with kidney transplantation. The aim of this study is to explore in patients with kidney transplantation whether AZA-related side effects can be explained by the inosine triphophate pyrophosphatase (ITPA) or thiopurine S-methyltransferase (TPMT) polymorphisms using both pheno-and genotyping. Erythrocyte ITPA and TPMT activity of 155 patients with kidney transplantation and AZA therapy was determined by HPLC.

Effects of Schisandra sphenanthera extract on the pharmacokinetics of midazolam in healthy volunteers.

Aims: To assess the effect of Schisandra sphenanthera extract (SchE) on the pharmacokinetics of midazolam, a probe drug of CYP3A, and its metabolite 1'-hydroxy midazolam in healthy volunteers.

Methods: Twelve healthy male volunteers were orally treated with SchE, three capsules twice daily for 7 days. Pharmacokinetic investigations of oral midazolam administration at 15 mg were performed both before and at the end of the SchE treatment period.

Relationships between thiopurine S-methyltransferase polymorphism and azathioprine-related adverse drug reactions in Chinese renal transplant recipients.

Objective: To systematically investigate the relationships between thiopurine S-methyltransferase (TPMT) polymorphisms and azathioprine-related adverse drug reactions in patients with kidney transplantation.

Methods: Erythrocyte TPMT activity of 150 patients with kidney transplantation and AZA therapy was determined by HPLC. The frequency of four common TPMT mutant alleles, TPMT*2, *3A, *3B, and *3C was determined by allele-specific PCR and PCR-restriction fragment length polymorphism (PCR-RFLP) analysis.

Effects of Schisandra sphenanthera extract on the pharmacokinetics of tacrolimus in healthy volunteers.

Aim: To assess the effect of Schisandra sphenanthera extract (SchE) on the pharmacokinetics of tacrolimus in healthy volunteers.

Methods: Twelve healthy male volunteers were orally treated with SchE, three capsules twice daily for 13 days. Pharmacokinetic investigations of oral tacrolimus administration at 2 mg were performed both before and at the end of the SchE treatment period.