Atomoxetine is the first non-stimulant drug for the treatment of children and adults with attention deficit hyperactivity disorder (ADHD), and its safety and efficacy show significant differences in the pediatric population. This article reviews the genetic factors influencing the pharmacokinetic differences of atomoxetine from the aspect of the gene polymorphisms of the major metabolizing enzyme CYP2D6 of atomoxetine, and then from the perspective of therapeutic drug monitoring, this article summarizes the reference ranges of the effective concentration of atomoxetine in children with ADHD proposed by several studies. In general, there is an association between the peak plasma concentration of atomoxetine and clinical efficacy, but with a lack of data from the Chinese pediatric population. Therefore, it is necessary to establish related clinical indicators for atomoxetine exposure, define the therapeutic exposure range of children with ADHD in China, and combine CYP2D6 genotyping to provide support for the precision medication of atomoxetine.
Adult ; Child ; Humans ; Adrenergic Uptake Inhibitors/therapeutic use* ; Atomoxetine Hydrochloride/therapeutic use* ; Attention Deficit Disorder with Hyperactivity/genetics* ; Cytochrome P-450 CYP2D6/therapeutic use* ; Drug Monitoring ; Genetic Testing ; Propylamines/therapeutic use* ; Treatment Outcome

BACKGROUND: High on-clopidogrel platelet reactivity could be partially explained by loss-of-function alleles of CYP2C19, the enzyme that converts clopidogrel into its active form. Shexiang Tongxin Dropping Pill (STDP) is a traditional Chinese medicine to treat angina pectoris. STDP has been shown to improve blood flow in patients with slow coronary flow and attenuate atherosclerosis in apolipoprotein E-deficient mice. However, whether STDP can affect platelet function remains unknown. OBJECTIVE: The purpose of this study is to examine the potential effects of STDP on platelet function in patients undergoing percutaneous coronary intervention (PCI) for unstable angina. The interaction between the effects of STDP with polymorphisms of CYP2C19 was also investigated. DESIGN, PARTICIPANTS AND INTERVENTION: This was a single-center, randomized controlled trial in patients undergoing elective PCI for unstable angina. Eligible subjects were randomized to receive STDP (210 mg per day) plus dual antiplatelet therapy (DAPT) with clopidogrel and aspirin or DAPT alone. MAIN OUTCOME MEASURES: The primary outcome was platelet function, reflected by adenosine diphosphate (ADP)-induced platelet aggregation and platelet microparticles (PMPs). The secondary outcomes were major adverse cardiovascular events (MACEs) including recurrent ischemia or myocardial infarction, repeat PCI and cardiac death; blood biomarkers for myocardial injury including creatine kinase-MB isoenzyme (CK-MB) and high-sensitive troponin I (hsTnI); and biomarkers for inflammation including intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein-1 (MCP-1) and galectin-3. RESULTS: A total of 118 subjects (mean age: [66.8 ± 8.9] years; male: 59.8%) were included into analysis: 58 in the control group and 60 in the STDP group. CYP2C19 genotype distribution was comparable between the 2 groups. In comparison to the control group, the STDP group had significantly lower CK-MB (P < 0.05) but similar hsTnI (P > 0.05) at 24 h after PCI, lower ICAM-1, VCAM-1, MCP-1 and galectin-3 at 3 months (all P < 0.05) but not at 7 days after PCI (P > 0.05). At 3 months, the STDP group had lower PMP number ([42.9 ± 37.3] vs. [67.8 ± 53.1] counts/μL in the control group, P = 0.05). Subgroup analysis showed that STDP increased percentage inhibition of ADP-induced platelet aggregation only in slow metabolizers (66.0% ± 20.8% in STDP group vs. 36.0% ± 28.1% in the control group, P < 0.05), but not in intermediate or fast metabolizers. The rate of MACEs during the 3-month follow-up did not differ between the two groups. CONCLUSION: STDP produced antiplatelet, anti-inflammatory and cardioprotective effects. Subgroup analysis indicated that STDP inhibited residual platelet reactivity in slow metabolizers only. TRIAL REGISTRATION This study was registered on www.chictr.org.cn: ChiCTR-IPR-16009785.
Adenosine Diphosphate ; Angina, Unstable/chemically induced* ; Animals ; Biomarkers ; Clopidogrel ; Cytochrome P-450 CYP2C19/genetics* ; Drugs, Chinese Herbal ; Galectin 3 ; Humans ; Intercellular Adhesion Molecule-1 ; Male ; Mice ; Percutaneous Coronary Intervention/adverse effects* ; Platelet Aggregation Inhibitors/adverse effects* ; Vascular Cell Adhesion Molecule-1/genetics*

Objective: To investigate the effects of clopidogrel resistence and CYP2C19 genotype on the clinical prognosis of acute coronary syndrome(ACS) patients undergoing percutaneous coronary intervention(PCI). Methods: This study was a retrospective cohort study. ACS patients who underwent PCI in Beijing Anzhen Hospital from October 2015 to January 2017 were recruited. The inhibition rate of adenosine diphosphate(ADP) was monitored by thromboelastography. All of these patients were divided into clopidogrel resistance and non-resistance group according to the monitoring results. CYP2C19 genotype was detected by TaqMan probe-based real-time quantitative PCR. Patients were divided into slow, medium and fast metabolic group, according to the CYP2C19 genotype. After 12 months of follow-up, the end points included all-cause death, cardiac death, angina, myocardial infarction, stent thrombosis, ischemic stroke and hemorrhage were collected. Combined thrombotic events were defined as a composite of angina, myocardial infarction, stent thrombosis and ischemic stroke. The differences of the incidence of clinical events between groups were compared. Cox regression was used to analyze the effects of clopidogrel resistance and CYP2C19 genotype on the combined thrombotic events, cardiac death and hemorrhage. Results: A total of 1 696 patients were included, and the age was (59.4±9.6) years, with 1 280(75.5%) males. There were 471 cases(27.8%) in clopidogrel resistance group, and 1 225 cases(72.2%) in clopidogrel non-resistance group. There were 218 patients(12.9%) were in slow metabolic group, 668(39.4%) in medium metabolic group, and 810 (47.8%) in fast metabolic group. The median follow-up time was 13.3 months, and 131 cases were lost to follow-up, with a loss follow-up rate of 7.7%. Compared with the clopidogrel non-resistance group, the clopidogrel resistance group had a higher incidence of myocardial infarction(7.6%(36/471) vs. 5.1%(62/1 225), P=0.041), a lower incidence of hemorrhage (13.2%(62/471) vs. 17.9%(219/1 225), P=0.020) and minor hemorrhage(11.5%(54/471) vs. 15.8% (194/1 225), P=0.022). There were no statistically significant difference in all-cause death, cardiac death, angina, stent thrombosis, ischemic stroke and severe bleeding between clopidogrel resistance and non-resistance group(all P>0.05). There was no statistically significant difference in the incidence of endpoint events among different CYP2C19 genotypes (all P>0.05). Cox regression analysis showed that clopidogrel resistance was an independent factor of combined thrombotic events (OR=2.334, 95%CI 1.215-4.443, P=0.016) and bleeding events (OR=0.481, 95%CI 0.174-0.901, P=0.023). While CYP2C19 genotype was not independent factor for combined thrombotic events, cardiac death and hemorrhage (all P>0.05). Conclusion: For ACS patients after PCI, clopidogrel resistance can increase the risk of combined thrombotic events, but also reduce the risk of bleeding; while CYP2C19 genotype is not an independent factor for clinical prognosis.
Acute Coronary Syndrome/genetics* ; Clopidogrel/therapeutic use* ; Cytochrome P-450 CYP2C19/genetics* ; Genotype ; Humans ; Male ; Percutaneous Coronary Intervention ; Platelet Aggregation Inhibitors/therapeutic use* ; Prognosis ; Retrospective Studies ; Treatment Outcome

With the widespread use of traditional Chinese medicine(TCM) and the integration of TCM and western medicine, drug-drug interaction(DDI) is considered as a major cause of therapeutic failures and side effects. Cytochrome P450 enzymes(CYPs) are responsible for large number of drug metabolism. CYP3 A4 and CYP2 D6, two important CYP isoforms, are responsible for about 80% drug metabolism of CYPs super family. The inhibition of CYPs is likely to be the most common factor leading to adverse DDI. Therefore, it is of great significance to predict potential CYP3 A4 and CYP2 D6 inhibitors to prevent the DDI. A fast and low-cost me-thod for calculating and predicting CYP inhibiting components was established in this paper, namely support vector machine(SVM) and molecular docking technology which are used to predict and screen drugs. Firstly, 12 qualitative models of two targets were established by using SVM, and the optimal model was selected to predict the compounds in traditional Chinese medicine database(TCMD). Then, molecular docking technology was used to establish docking model. By analyzing the key amino acids involved in drug-target interactions and combining with SVM model, potential inhibitors of CYP3 A4 and CYP2 D6 were found. From the computational results, astin D and epiberberine exhibited inhibition effect on CYP3 A4 and CYP2 D6, respectively. Astin D was only found in astins family from Aster tataricus, while epiberberine was considered to be the active constituent of Coptidis Rhizoma. Therefore, for the risk of DDI, extra attention should be paid to the source of these potential inhibitors, Asteris Radix et Rhizoma and Coptidis Rhizoma. This computational method provides technical support for discovering potential natural inhibitors of CYPs from Chinese herbs by using SVM and molecular docking model, and it is also helpful to recognize the CYPs-mediated DDI existing in TCM, providing research ideas for further pharmacovigilance of integrated therapy.
Cytochrome P-450 Enzyme Inhibitors/analysis* ; Cytochrome P-450 Enzyme System ; Drugs, Chinese Herbal/chemistry* ; Medicine, Chinese Traditional ; Molecular Docking Simulation ; Plants, Medicinal/chemistry*

This study investigated the inhibitory effect of eight natural flavonoids in Chinese herb Scutellariae Radix on huamn cytochrome P450 1 A(CYP1 A), a key cancer chemo-preventive target. In this study, phenacetin was used as a probe substrate for CYP1 A, while human liver microsomes and recombinant human CYP1 A enzymes were used as enzyme sources. Liquid chromatography-tandem mass spectrometry was used to monitor the formation rates of acetaminophen, the O-deethylated metabolite of phenacetin. The dose-dependent inhibition curves were depicted based on the changes of the formation rates of acetaminophen, while the IC_(50) were determined. Inhibition kinetic analyses and docking simulations were used to investigate the inhibition modes and mechanism of wogonin(the most potent CYP1 A inhibitor in this herb), while the inhibition constants(K_i) of wogonin against both CYP1 A1 and CYP1 A2 were determined. Among all tested flavonoids, wogonin, 7-methoxyflavanone and oroxylin A displayed a strong inhibitory effect on CYP1 A(IC_(50)<1 μmol·L~(-1)), baicalein exhibited a moderate inhibitory effect on CYP1 A(IC_(50) between 1-10 μmol·L~(-1)), and baicalin, scutellarein and wogonoside displayed a very weak inhibitory effect on CYP1 A(IC_(50) between 10-25 μmol·L~(-1)), but scutellarin displayed a negligible inhibitory effect on CYP1 A(IC_(50)>100 μmol·L~(-1)). Further investigations demonstrated that wogonin had a weak inhibitory effect on other human CYP enzymes, suggesting that it could be used as a lead compound for the development of specific inhibitors of CYP1 A. Furthermore, the inhibition kinetic analyses clearly demonstrated that wogonin could strongly inhibit phenacetin O-deethylation in both CYP1 A1 and CYP1 A2 in a competitive manner, with K_i values at 0.118 and 0.262 μmol·L~(-1), respectively. Molecular docking demonstrated that wogonin could strongly interact with CYP1 A1 and CYP1 A2 via hydrophobic and π-π interactions, as well as Ser120 and Ser116 in CYP1 A1 via hydrogen-bonding. In conclusion, this study found that some flavonoids in Scutellariae Radix displayed a strong inhibitory effect on CYP1 A, while wogonin is the most potent CYP1 A inhibitor with a relatively high selectivity towards CYP1 A over other human CYPs.
Chromatography, Liquid ; Cytochrome P-450 CYP1A1 ; antagonists & inhibitors ; Cytochrome P-450 Enzyme Inhibitors ; pharmacology ; Flavanones ; pharmacology ; Flavonoids ; pharmacology ; Humans ; Molecular Docking Simulation ; Scutellaria baicalensis ; chemistry

Pharmacogenetic testing for clinical applications is steadily increasing. Correct and adequate use of pharmacogenetic tests is important to reduce unnecessary medical costs and adverse patient outcomes. This document contains recommended pharmacogenetic testing guidelines for clinical application, interpretation, and result reporting through a literature review and evidence-based expert opinions for the clinical pharmacogenetic testing covered by public medical insurance in Korea. This document aims to improve the utility of pharmacogenetic testing in routine clinical settings.
Anticoagulants/therapeutic use ; Antidepressive Agents/therapeutic use ; Antimetabolites, Antineoplastic/therapeutic use ; Antitubercular Agents/therapeutic use ; Arylamine N-Acetyltransferase/genetics ; Coronary Artery Disease/drug therapy/genetics ; Cytochrome P-450 CYP2C19/genetics ; Cytochrome P-450 CYP2C9/genetics ; Cytochrome P-450 CYP2D6/genetics ; Depressive Disorder/drug therapy/genetics ; Genotype ; Isoniazid/therapeutic use ; Laboratories, Hospital/standards ; Methyltransferases/genetics ; Pharmacogenomic Testing/*methods/standards ; Platelet Aggregation Inhibitors/therapeutic use ; Pulmonary Embolism/drug therapy/genetics ; Ticlopidine/analogs & derivatives/therapeutic use ; Tuberculosis/drug therapy/genetics ; Vitamin K Epoxide Reductases/genetics ; Warfarin/therapeutic use

BACKGROUND AND PURPOSE: To compare the efficacy and safety of antiplatelet agents for the secondary prevention of ischemic stroke based on cytochrome P450 2C19 (CYP2C19) polymorphisms. METHODS: This study was a prospective, multicenter, randomized, parallel-group, open-label, blind genotype trial. First time non-cardiogenic ischemic stroke patients were enrolled and screened within 30 days. Participants were randomized to receive either triflusal or clopidogrel for secondary stroke prevention. The primary outcome was the time from randomization to first recurrent ischemic stroke or hemorrhagic stroke. RESULTS: The required sample size was 1,080 but only 784 (73%) participants were recruited. In patients with a poor CYP2C19 genotype for clopidogrel metabolism (n=484), the risk of recurrent stroke among those who received triflusal treatment was 2.9% per year, which was not significantly different from those who received clopidogrel treatment (2.2% per year; hazard ratio [HR], 1.23; 95% confidence interval [CI], 0.60–2.53). In the clopidogrel treatment group (n=393), 38% had good genotypes and 62% poor genotypes for clopidogrel metabolism. The risk of recurrent stroke in patients with a good CYP2C19 genotype was 1.6% per year, which was not significantly different from those with a poor genotype (2.2% per year; HR, 0.69; 95% CI, 0.26–1.79). CONCLUSIONS: Whilst there were no significant differences between the treatment groups in the rates of stroke recurrence, major vascular events, or coronary revascularization, the efficacy of antiplatelet agents for the secondary prevention of stroke according to CYP2C19 genotype status remains unclear.
Cytochrome P-450 CYP2C19 ; Cytochrome P-450 Enzyme System* ; Cytochromes* ; Genotype ; Humans ; Metabolism ; Platelet Aggregation Inhibitors ; Prospective Studies ; Random Allocation ; Recurrence ; Sample Size ; Secondary Prevention* ; Stroke*

BACKGROUND/AIMS: Concerns that proton pump inhibitors (PPIs) diminish the efficacy of clopidogrel could hamper the appropriate prescription of PPIs. We evaluated the influence of pantoprazole on the antiplatelet effect of clopidogrel compared with ranitidine, which is regarded as safe, after stratification of the population according to the presence of a cytochrome (CYP) 2C19 polymorphism in Korea. METHODS: Forty patients who underwent dual antiplatelet therapy were randomized to receive pantoprazole (n=20) or ranitidine (n=20). Platelet aggregation was evaluated by impedance aggregometry at baseline (D0) and 8 days after acid-lowering treatments (D9). CYP2C19 was genotyped by polymerase chain reaction restriction fragment length polymorphism. RESULTS: After co-treatment, the percentage of clopidogrel low-response was 11.1% (2/18) in the pantoprazole group and 10.5% (2/19) in the ranitidine group (p=0.954). The impedance values with adenosine diphosphate stimulus after acid-lowering treatments did not significantly differ between the two groups. In a multiple regression analysis, only ST-elevation myocardial infarction was marginally associated with a reduced antiplatelet effect (odds ratio, 12.07; 95% confidence interval, 0.84 to 173.78). However, pantoprazole use did not affect the antiplatelet effect after correction for the CYP2C19 polymorphism. CONCLUSIONS: This study showed that pantoprazole does not increase platelet aggregation in patients receiving dual antiplatelet therapy (ClinicalTrials.gov number: NCT02733640).
Adenosine Diphosphate ; Cytochrome P-450 CYP2C19 ; Cytochromes ; Drug Interactions ; Electric Impedance ; Humans ; Korea* ; Myocardial Infarction ; Platelet Aggregation ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Prescriptions ; Proton Pump Inhibitors ; Ranitidine

<p>OBJECTIVETo assess the association of CYP2C19 gene polymorphisms with the incidence of ischemic stroke among patients receiving clopidogrel therapy following coronary stenting for coronary artery disease.p><p>METHODSClinical data of patients receiving clopidogrel therapy after coronary stenting were retrospectively studied. For a case-control study, 137 patients with acute cerebral infarction and 122 non-stroke patients were selected. Based on the variants of the CYP2C19 gene detected by a DNA microarray assay, the patients were further divided into the wild-type group(CYP2C19*1/*1) and mutant group(defined by the presence of at least one loss-of-function allele, including CYP2C19*1/*2, CYP2C19*1/*3, CYP2C19*2/*2, CYP2C19*2/*3 and CYP2C19*3/*3). The incidences of ischemic stroke in the two groups were compared through a chi-square analysis. The influence of CYP2C19 gene polymorphisms and clopidogrel therapy on the incidence of ischemic stroke was analyzed through multivariable logistic regression.p><p>RESULTSA total of 259 patients were enrolled. The case and control groups showed no difference in terms of gender and age. There were 123 cases (47.5%) in the CYP2C19 wild-type group and 136 cases (52.5%) in the mutant group. The incidence of ischemic stroke of mutant group was significantly higher than that of wild-type group (59.9% vs. 44.3%, X2=6.398, P=0.042). Multivariate analysis revealed that loss-of-function polymorphisms of the CYP2C19 gene carried a 1.13 times greater risk for ischemic stroke compared to wild-type genotype (OR=2.13, 95%CI: 1.23-3.71).p><p>CONCLUSIONThe efficacy of clopidogrel for the prevention of ischemic stroke in post-coronary stent patients may be reduced by the insufficiency of the CYP2C19 gene. The dosage of clopidogrel therapy should be adjusted based on its polymorphisms.p>
Brain Ischemia ; prevention & control ; Cytochrome P-450 CYP2C19 ; genetics ; Genotype ; Humans ; Percutaneous Coronary Intervention ; adverse effects ; Platelet Aggregation Inhibitors ; therapeutic use ; Polymorphism, Genetic ; Stents ; adverse effects ; Stroke ; prevention & control ; Ticlopidine ; analogs & derivatives ; therapeutic use

BACKGROUND: An association has been reported between CYP2C19 polymorphism and the altered antiplatelet activity of clopidogrel. We investigated this association using the newly introduced platelet function analyzer (PFA)-200 (INNOVANCE PFA-200 System; Siemens Healthcare, Germany) P2Y test. METHODS: Polymorphisms of CYP2C19*2, *3, *17 and the degree of inhibition of platelet function were determined in 83 patients. Three different platelet function tests were used to evaluate the degree of platelet inhibition and to check the association with genotype. RESULTS: The post-procedure PFA-200 values of extensive metabolizers (EM) patients (285.3+/-38.8) were higher than those of intermediate metabolizers (IM) and poor metabolizers (PM) patients (227.7+/-98.3 and 133.7+/-99.2, respectively; P=0.024). Light transmittance aggregometry (LTA) and the VerifyNow system showed that the post-procedure values for EM patients were lower than those of IM and PM patients (LTA: 24.4+/-15.7, 34.1+/-17.6, and 42.2+/-16.9, respectively, P<0.001; VerifyNow: 133.2+/-60.5, 171.5+/-42.6, and 218.7+/-59.3, respectively, P<0.001). The high residual platelet reactivity (HPR) rates were significantly different among the EM, IM, and PM groups using PFA-200 (PM:IM:EM=82.4:40.6:11.8, P<0.001). CONCLUSIONS: Approximately, 59.0% of Korean patients with cardiovascular disease receiving clopidogrel had CYP2C19 loss-of-function genotypes classified as IM or PM, and the frequency was similar to the data from Asian people. The PFA-200, LTA, and VerifyNow platelet function tests revealed evidence of a significant association between the efficacy of clopidogrel and CYP2C19 genotypes.
Aged ; Cardiovascular Diseases/blood/*drug therapy ; Cytochrome P-450 CYP2C19/*genetics/metabolism ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Phenotype ; Platelet Aggregation Inhibitors/*therapeutic use ; Platelet Function Tests/instrumentation ; Polymorphism, Genetic ; Ticlopidine/*analogs & derivatives/therapeutic use