BACKGROUND:Tyrosine kinase inhibitor (TKI) and rivaroxaban co-administration is common for patients with cancer and venous thromboembolism. However, the drug-drug interactions (DDIs) between epidermal growth factor receptor (EGFR) TKIs and rivaroxaban remain uncertain. METHODS:DDIs were investigated in vitro and in vivo. In vitro experiments were conducted using rat liver microsomes, and rivaroxaban metabolites were tested to identify the two TKIs that exhibit the most significant DDIs. The type of inhibition was investigated using Lineweaver-Burk plots. For in vivo experiments, eighteen rats were randomly divided into three groups and pretreated with CMC-Na together with avitinib or gefitinib, or with CMC-Na alone for 7 days. On day 8, rivaroxaban was orally administered to each group. Blood samples were collected at various time points, and plasma rivaroxaban was quantified. Molecular docking was performed to explore the mechanism of DDIs. RESULTS:Avitinib and gefitinib showed the most potent inhibitory effects among multiple EGFR TKIs and inhibited rivaroxaban metabolism in a mixed model of noncompetitive and uncompetitive inhibition. The area under the drug-time curve and maximum plasma concentration of rivaroxaban were significantly higher following avitinib and gefitinib pretreatment, while the apparent volume of distribution and clearance rates were significantly lower. Our molecular docking analysis revealed that these two drugs may inhibit rivaroxaban metabolism by overlapping with its binding site on CYP3A4 and CYP2D6. CONCLUSION:These findings confirm the presence of DDIs between EGFR TKIs and rivaroxaban. Avitinib and gefitinib significantly inhibit rivaroxaban metabolism, and their co-administration may aggravate the risk of bleeding.

Existing pharmacogenetic algorithms cannot fully explain warfarin dose variability in all patients. CYP2C9*13 is an important allelic variant in the Han Chinese population. However, adjustment of warfarin dosing in CYP2C9*13 variant carriers remains unclear. To the best of our knowledge, this study is the first to assess the effects of adjusting warfarin dosages in Han Chinese patients harbouring CYP2C9*13 variants. In total, 971 warfarin-treated Han Chinese patients with atrial fibrillation were enrolled in this study. Clinical data were collected, and CYP2C9*2, *3, *13 and VKORC1-1639 G > A variants were genotyped. We quantitatively analysed the effect of CYP2C9*13 on warfarin maintenance dose and provided multiplicative adjustments for CYP2C9*13 using validated pharmacogenetic algorithms. Approximately 0.6

Cytochrome P450 2C9 (CYP2C9) participates in about 15% of clinical drug metabolism, and its polymorphism is associated with individual drug metabolism differences, which may lead to the adverse drug reactions (ADRs). In this study, 1163 Chinese Han individuals were recruited to investigate their distribution pattern of CYP2C9 gene and find out the variants that may affect their drug metabolic activities. We successfully developed a multiplex PCR amplicon sequencing method and used it for the genetic screening of CYP2C9 in a large scale. Besides the wild type CYP2C9*1, totally 26 allelic variants of CYP2C9 were detected, which included 16 previously reported alleles and 10 new non-synonymous variants that had not been listed on the PharmVar website. The characteristics of these newly detected CYP2C9 variants were then evaluated after co-expressing them with CYPOR in S. cerevisiae microsomes. Immunoblot analysis revealed that except for Pro163Ser, Glu326Lys, Gly431Arg and Ile488Phe, most of newly detected variants showed comparable protein expression levels to wild type in yeast cells. Two typical CYP2C9 probe drugs, losartan and glimepiride, were then used for the evaluation of metabolic activities of variants. As a result, 3 variants Thr301Met, Glu326Lys, and Gly431Arg almost lost their catalytic activities and most of other variants exhibited significantly elevated activities for drug metabolism. Our data not only enriches the knowledge of naturally occurring CYP2C9 variants in the Chinese Han population, but also provides the fundamental evidence for its potential clinical usage for personalized medicine in the clinic.

Backgrounds:Gene polymorphisms are critical for variations in warfarin dose. To date, more than 70 CYP2C9 alleles have been identified. This study was designed to clarify the clinical significance of CYP2C9*non-3 variants to warfarin sensitivity in Chinese Han patients.Methods:The entire CYP2C9 gene region was sequenced in 1,993 individuals, and clinical data and VKORC1 genotypes were collected from 986 patients with atrial fibrillation treated with warfarin. The SKAT-O method was used to analyze the effects of CYP2C9*non-3 variants on warfarin sensitivity.Results:A total of 20 CYP2C9 variants were identified, of which four were novel. Carriers with CYP2C9*non-3 variants may have lower warfarin dose requirements, and similar to CYP2C9*3, CYP2C9*non-3 variants are clearly relevant to warfarin-sensitive and highly sensitive responders.Conclusion:Our results showed that, besides CYP2C9*3, the series of CYP2C9*non-3 variants is an unignorable predictor for warfarin sensitivity in Chinese population. From a safety consideration, people carried such variants may need a preferred choice of NOACs when they started anticoagulation therapy.

Food–drug interactions are reported to have some impacts on the pharmacokinetics and pharmacodynamics of various oral drugs. To better understand the effects of naringenin, one natural product in many fruits, on the pharmacokinetics of rivaroxaban, drug–drug interactions (DDIs) between naringenin and rivaroxaban in vitro were investigated in Sprague–Dawley (SD) rat liver microsomes. For the DDIs in vivo, 12 male SD rats were randomly divided into the experimental group and the control group with six rats in each group. Rats in the experimental group were pre‐treated with naringenin (10 mg/kg/day) for 2 weeks before the administration of rivaroxaban (10 mg/kg) by oral gavage, while the rats in the control group were given rivaroxaban (10 mg/kg) only once. The plasma concentration of rivaroxaban in rats was then measured by UPLC‐MS/MS. In vitro data indicated that naringenin could decrease the metabolic clearance rate of rivaroxaban with the IC 50 value of 38.89 μM, and exhibited a mixed inhibition to rivaroxaban (Ki =54.91 μM, aKi =73.33 μM, a = 0.74). In vivo data in rats revealed that as compared with that of the control group, the AUC (0– t ) value of rats in the experimental group was increased from 2406.28 ± 519.69 μg/h/L to 4005.04 ± 1172.76 μg/h/L, the C max value was increased from 310.23 ± 85.76 μg/L to 508.71 ± 152.48 μg/L, and the V z / F and CL z / F were decreased from 23.03 ± 4.81 L/kg to 16.2 ± 8.42 L/kg, 4.26 ± 0.91 L/h/kg to 2.57 ± 0.73 L/h/kg, respectively. These data indicated that naringenin had an inhibitory effect on the pharmacokinetics of rivaroxaban in rats, suggesting that the DDIs between naringenin and rivaroxaban might occur when they were co‐administered in the clinic.

Cytochrome P450 2C9 (CYP2C9) is one of the most important drugs metabolizing enzymes and accounts for the metabolism of about 13%-17% of clinical drugs. Like other members in CYP2 family, CYP2C9 gene exhibits great genetic polymorphism among different races and individuals. CYP2C9*18 is one CYP2C9 allelic variant identified in a Southeast Asian population and is estimated to cause the amino acid substitutions of I359L and D397A in CYP2C9 enzyme simultaneously. Limited by the low expression level in bacteria and COS-7 cells, no valuable enzyme kinetics have been reported on this CYP2C9 variant. In this study, the baculovirus-based system was used for the high expression of recombinant CYP2C9 s in insect cells. As a result, together with I359L substitution, D397A could significantly decrease the protein expression of CYP2C9.18 in insect cells, although substitution of D397A alone had no effect on the expression of CYP2C9 in vitro. As compared with that of wild-type enzyme, both CYP2C9.18 variant and D397A variant could decrease more than 80% of the catalytic activity of CYP2C9 enzyme toward three probe substrates, suggesting that caution should be exercised when patients carrying CYP2C9*18 taking medicines metabolized by CYP2C9 enzyme with a narrow therapeutic window.

Context Rivaroxaban and ticagrelor are two common drugs for the treatment of atrial fibrillation and acute coronary syndrome. However, the drug–drug interaction between them is still unknown. Objective To investigate the effects of ticagrelor on the pharmacokinetics of rivaroxaban in rats both in vivo and in vitro. Materials and methods A sensitive and reliable UPLC-MS/MS method was developed for the determination of rivaroxaban in rat plasma. Ten Sprague-Dawley rats were randomly divided into ticagrelor pre-treated group (10 mg/kg/day for 14 days) and control group. The pharmacokinetics of orally administered rivaroxaban (10 mg/kg, single dose) with or without ticagrelor pre-treatment was investigated with developed UPLC-MS/MS method. Additionally, Sprague-Dawley rat liver microsomes were also used to investigate the drug–drug interaction between these two drugs in vitro. Results The Cmax (221.34 ± 53.33 vs. 691.18 ± 238.31 ng/mL) and the AUC(0–t) (1060.97 ± 291.21 vs. 3483.03 ± 753.83 μg·h/L) of rivaroxaban increased significantly (p < 0.05) with ticagrelor pre-treatment. The MRT(0–∞) of rivaroxaban increased from 4.41 ± 0.79 to 5.97 ± 1.11 h, while the intrinsic clearance decreased from 9.93 ± 2.55 to 2.89 ± 0.63 L/h/kg (both p < 0.05) after pre-treated with ticagrelor. Enzyme kinetic study indicated that ticagrelor decreased rivaroxaban metabolic clearance with the IC50 value of 14.04 μmol/L. Conclusions Our in vivo and in vitro results demonstrated that there is a drug–drug interaction between ticagrelor and rivaroxaban in rats. Further studies need to be carried out to verify whether similar interactions truly apply in humans and whether these interactions have clinical significance.

Warfarin is the most commonly used anticoagulant in the clinical treatment of thromboembolic diseases. The dose of warfarin varies significantly within populations, and the dose is closely related to the genetic polymorphisms of the CYP2C9 and VKORC1 genes. In this study, a new CYP2C9 nonsynonymous mutation (8576C > T) was detected after the genetic screening of 162 patients took warfarin. This mutation, named as the new allele CYP2C9*62, can result in an arginine to cysteine amino acid substitution at position 125 of the CYP2C9 protein (R125C). When expressed in insect cells, the protein expression of CYP2C9.62 was significantly lower than that of the wild-type, and its metabolic activity was also significantly decreased after the addition of three typical CYP2C9 probe drugs, suggesting that the new mutant can dramatically affect the metabolism of CYP2C9 drugs in vitro.

目的:探究除细胞色素P4502C9(CYP2C9)*2和CYP2C9*3以外的少见CYP2C9等位基因对中国汉族心房颤动患者华法林稳态剂量的影响,并构建新的预测模型.方法:选取2011年1月至2017年3月在我院接受华法林抗凝治疗的心房颤动患者681例,随机以2:1的比例分为建模组(n=454)和验证组(n=227).采用PCR直接测序分析CYP2C9和维生素K环氧化物还原酶复合体1(VKORC1)基因型,通过单因素相关分析筛选与华法林稳态剂量相关的变量,采用多元线性回归分析建立华法林稳态剂量预测模型.结果:发现了三种少见CYP2C9等位基因(CYP2C9*13、*16、*60),均为杂合子.综合这三种少见基因型,建立变量CYP2C9(13/16/60),其华法林稳态剂量显著低于CYP2C9*1/*1(P<0.001)及CYP2C9*1/*3(P<0.05).构建中国汉族人群特异的包含有其他少见CYP2C9基因突变变量的华法林稳态剂量预测方程,华法林日剂量=exp[0.524+0.344× 体 表 面 积-0.082× 胺 碘 酮-0.393×CYP2C9*3-0.740×CYP2C9(13/16/60)+0.276×VKORC1-1639GA+0.593×VKORC1-1639GG]R2=44.3％.其中CYP2C9(13/16/60)占总基因型频率的0.7％,但可以解释6.3％的华法林剂量个体差异.将研究模型应用于验证组,相关系数达0.567.结论:CYP2C9*13、*16、*60等位基因与更低的华法林稳态剂量相关,新构建的纳入有上述少见CYP2C9等位基因变量的预测方程可以更好地预测中国汉族人群华法林稳态剂量.

Aim:Gene polymorphisms are critical in warfarin dosing variation. Here, the role of rareCYP2C9alleles on warfarin doses in Chinese Han patients was investigated.Methods:A retrospective study recruited 681 warfarin treated atrial fibrillation patients. The genetic and clinical data were collected. Dose-related variables were selected by univariate analyses and the warfarin-dosing algorithm was derived by multivariate regression analysis.Results:Three rareCYP2C9alleles (CYP2C9*13, *16 and *60) were associated with lower stable doses. Inclusion of the rareCYP2C9alleles in the prediction model added an extra 3.7% warfarin dose predictive power.Conclusion:CYP2C9*13, *16 and *60 was associated with lower stable warfarin doses in Chinese patients. The algorithm including rareCYP2C9alleles tends to more accurately predict stable warfarin doses.

目的:分析对肝阳上亢型高血压患者给予天麻钩藤饮治疗的临床疗效.方法:将本院2015年11月-2017年9月收治的62例肝阳上亢型高血压患者作为观察对象,采用随机数字表法将患者分为对照组和研究组,各31例.对照组给予苯磺酸左旋氨氯地平片治疗,研究组给予苯磺酸左旋氨氯地平片联合中药汤剂天麻钩藤饮进行治疗,治疗4周,观察两组患者治疗前后中医临床证候、血压变化及不良反应发生情况.结果:治疗后,两组血压较治疗前明显降低(P＜0.05),但两组治疗前后血压比较差异无统计学意义(P＞0.05);两组患者临床效果良好,研究组总有效率为93.5％,但差异无统计学意义(P＞0.05),研究组显效率高于对照组(P＜0.05);两组患者头痛、眩晕、口苦口干、烦躁易怒症状积分均明显降低,研究组症状改善情况优于对照组,差异有统计学意义(P＜0.05).研究组未见患者出现不良反应.结论:天麻钩藤饮与西药苯磺酸左旋氨氯地平片联用,对于肝阳上亢型高血压具有显著降压作用,较苯磺酸左旋氨氯地平片临床显效率高,可显著改善患者临床症状,且未见明显不良反应,为临床应用提供参考.

目的:华法林是目前最为广泛使用的抗凝药物,其稳态剂量受到众多临床因素和遗传因素影响.细胞色素 P4502C9 是人类肝微粒体中一种重要的药物代谢酶,华法林通过CYP2C9 基因编码的细胞色素酶 P450 代谢转化为无活性的 6、7- 羟化产物实现抗凝效果.CYP2C9 基因具有遗传多态性,目前已发现 60 余种由单核苷酸多态造成的等位基因变异,其中相当部分等位基因变异可引起 CYP2C9 酶活性的改变从而影响华法林在体内的药物代谢过程.本研究旨在探索中国北方汉族人群华法林代谢关键酶细胞色素 P4502C9(CYP2C9)基因多态性位点的等位基因分布情况,以期丰富华法林药物基因组学数据库.

目的分析冠心病合并糖代谢异常患者的冠状动脉病变特点和糖代谢异常对经皮冠状动脉介入治疗（PCI）操作及住院期不良事件的影响。方法对184例糖代谢异常及147例糖代谢正常的冠心病患者进行回顾性分析。分析患者的冠状动脉病变特点,计算血管造影成功率、操作成功率以及临床成功率,分析糖代谢异常对住院期临床事件的影响。结果糖代谢异常组患者多支病变检出率明显高于糖代谢正常组患者,冠状动脉病变范围更广泛、程度更重、病变更复杂,更易累及小血管（P＜0.05）。糖代谢异常组与糖代谢正常组之间的血管造影成功率、操作成功率和临床成功率差异无统计学意义（分别为91.8%vs.93.9%,88.0%vs.91.8%及85.3%vs.90.5%,P均＞0.05）。Logistic多元回归分析显示糖代谢异常不是PCI术住院期发生不良事件的独立危险因素（OR=0.999,95%IC:0.242~9.172,P＞0.05）。结论糖代谢异常患者冠状动脉病变比糖代谢正常患者更复杂、严重;糖代谢异常不是PCI术住院期发生不良事件的独立危险因素。