What is already known about this subject • Schisandra sphenanthera extract (SchE) and tacrolimus are often co‐administrated in treating renal and liver transplant recipients in China. • We discovered occasionally that blood tacrolimus concentrations are markedly increased in some patients who receive tacrolimus and concomitant SchE. • This is the first study to investigate the effects of SchE on the pharmacokinetics of tacrolimus. What this study adds • Following administration of SchE in healthy volunteers, the mean AUC, AUMC and Cmax of tacrolimus substantially increases, whereas its CL/F and V/F decreases significantly. • Blood tacrolimus concentrations need to be closely monitored and dose adjustments of tacrolimus have to be made accordingly in the presence of SchE. 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. Whole blood tacrolimus concentrations were determined by enzyme‐linked immunosorbent assay. Estimated pharmacokinetic parameters before and with SchE were calculated with noncompartmental techniques. Results Following administration of SchE, the average percentage increases of individual increases in AUC, AUMC and Cmax of tacrolimus were 164.2% [95% confidence interval (CI) 70.1, 258.4], 133.1% (95% CI 49.5, 261.3) and 227.1% (95% CI 155.8, 298.4), respectively (P < 0.01 or 0.05). On average, there was a 36.8% (95% CI 13.4, 60.2) increase in tacrolimus tmax (P < 0.01). The average percentage decreases in CL/F and V/F were 49.0% (95% CI 31.1, 66.9) and 53.7% (95% CI 40.1, 67.4), respectively (P < 0.01). Conclusions SchE can increase the oral bioavailability of tacrolimus. The results of this study will add important information to the interaction area between drugs and herbal products.

The BBR can markedly elevate the blood concentration of CsA in renal-transplant recipients in both clinical and pharmacokinetic studies. This combination may allow a reduction of the CsA dosage. The mechanism for this interaction is most likely explained by inhibition of CYP3A4 by BBR in the liver and/or small intestine.

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Background: Conventional real-time PCR to quantify the allele ratio in pooled DNA mainly depends on PCR amplification efficiency determination and Ct value, which is defined as the PCR cycle number at which the fluorescence emission exceeds the fixed threshold. Because of the nature of exponential calculation, slight errors are multiplied and the variations of the results seem too large. We have developed a new PCR data point analysis strategy for allele ratio quantification based on normalized fluorescence ratio.

This study demonstrates that TPMT activity is reduced in patients with TPMT*3C mutation. AZA-induced hematotoxicity is related to the reduced TPMT activity.