• Disease
  • Cyp2D6
  • Cyp2D6 Genotype
  • Kosuke Doki

    Prominent publications by Kosuke Doki

    KOL Index score: 11361

    AIM: To assess whether or not co-administration of proton pump inhibitors (PPIs) is a risk factor for delayed elimination of plasma methotrexate (MTX) in high-dose MTX (HDMTX) therapy for malignant diseases.

    METHODS: To assess the effects of PPI co-administration on elimination of plasma MTX, we examined plasma MTX concentration data on 171 cycles of HDMTX therapy performed in 74 patients. We performed multiple logistic regression analysis to evaluate PPI co-administration as a risk ...

    Also Ranks for: Proton Pump |  methotrexate therapy |  delayed elimination |  plasma mtx |  ppi administration
    KOL Index score: 8549

    AIMS: The aim of this study was to clarify the effects of CYP2D6 genotype on age-related change in flecainide metabolism in patients with supraventricular tachyarrhythmias. An in vitro study using microsomes was performed to identify other CYPs responsible for age-related change in flecainide metabolism.

    METHODS: The study population comprised 111 genotyped patients: CYP2D6-homozygous extensive metabolizers (hom-EMs, n= 34), heterozygous EMs (het-EMs, n= 56), and intermediate and poor ...

    Also Ranks for: Cyp2d6 Genotype |  flecainide metabolism |  cytochrome p450 |  ims pms |  elderly patients
    KOL Index score: 8358

    ObjectiveTo examine the effect of CYP2D6 genotype on the pharmacokinetics of flecainide, we conducted a population pharmacokinetic analysis of the data collected during routine therapeutic drug monitoring of Japanese patients with supraventricular tachyarrhythmia.MethodsPopulation analysis was performed on retrospective data from 58 patients with normal kidney and liver function treated with oral flecainide for supraventricular tachyarrhythmia. Serum concentrations of flecainide were ...

    Also Ranks for: Supraventricular Tachyarrhythmia |  japanese patients |  cyp2d6 genotype |  flecainide pharmacokinetics |  retrospective data
    KOL Index score: 8231

    BACKGROUND: Erlotinib is used for treating non-small cell lung cancer (NSCLC). Intestinal absorption of erlotinib is impaired under gastric pH elevation; therefore, coadministration of gastric acid suppressants may provide lower blood concentration of erlotinib. We investigated the effects of erlotinib coadministration with proton pump inhibitors (PPIs) and histamine H2 receptor blockers (H2RBs) on the plasma concentration of erlotinib and erlotinib-induced adverse reaction in patients ...

    Also Ranks for: Proton Pump |  cell lung |  erlotinib patients |  plasma concentration |  gastric acid suppressants
    KOL Index score: 7715

    OBJECTIVE: An increased slowing of cardiac conduction induced by sodium channel blockers is remarkably observed in carriers of an Asian-specific promoter haplotype [haplotype B (HapB)] of the cardiac sodium channel gene (SCN5A). We investigated the effect of HapB on the therapeutic range for serum flecainide concentration in Asian patients.

    PATIENTS AND METHODS: We examined the serum concentration and antiarrhythmic efficacy of flecainide, together with the SCN5A promoter haplotype, in ...

    Also Ranks for: Serum Flecainide |  therapeutic range |  scn5a promoter haplotype |  antiarrhythmic efficacy |  sodium channel
    KOL Index score: 7018

    Plasma concentrations of dabigatran, an active principle of prodrug dabigatran etexilate (DABE), are increased by renal impairment (RI) or coadministration of a P-glycoprotein inhibitor. Because the combined effects of drug-drug interactions and RI have not been evaluated by means of clinical studies, the decision of DABE dosing for RI patients receiving P-glycoprotein inhibitors is empirical at its best. We conducted virtual drug-drug interactions studies between DABE and the ...

    Also Ranks for: Drug Interactions |  dabigatran etexilate |  renal impairment |  based pharmacokinetic |  plasma concentrations
    KOL Index score: 6042

    Majority of bioequivalence studies are conducted in healthy volunteers. It has been argued that bioequivalence may not necessarily hold true in relevant patient populations due to a variety of reasons which affect one formulation more than the other for instance in achlorhydric patients where elevated gastric pH may lead to differential effects on formulations which are pH-sensitive with respect to release or dissolution. We therefore examined achlorhydria-related disparity in ...

    Also Ranks for: Virtual Bioequivalence |  pbpk modelling |  aged models |  biorelevant media |  reference formulations
    KOL Index score: 5659

    OBJECTIVE: To investigate the association between age-related decline in flecainide clearance and CYP2D6 genotype, we conducted a population pharmacokinetic analysis of flecainide using routine therapeutic drug monitoring data.

    METHODS: Population pharmacokinetic analysis was performed on retrospective data from 163 genotyped patients treated with oral flecainide for supraventricular tachyarrhythmias. The CYP2D6 genotype was categorized as CYP2D6 homozygous extensive metabolizers ...

    Also Ranks for: Cyp2d6 Genotype |  flecainide clearance |  ims pms |  drug monitoring |  agerelated decline
    KOL Index score: 5361

    ObjectiveWe examined the effect of gender-associated differences in pharmacokinetics on the anti-arrhythmic effects of flecainide in Japanese patients with supraventricular tachyarrhythmia and in healthy subjects.MethodsThe study population comprised 72 outpatients (52 males and 20 females) treated with oral flecainide for supraventricular tachyarrhythmias. Serum flecainide concentrations were determined by use of high-performance liquid chromatography. The anti-arrhythmic efficacy of ...

    Also Ranks for: Holter Monitoring |  2 months |  aged anti |  patients supraventricular |  serum flecainide concentrations
    KOL Index score: 5205

    OBJECTIVES: The aim was to compare blood tacrolimus concentrations in anaemic patients between affinity column-mediated immunoassay (ACMIA) and microparticle enzyme immunoassay (MEIA).

    METHODS: Blood concentrations of tacrolimus in 235 whole-blood samples from 64 patients treated with tacrolimus were determined by the two assay methods. Fifty-three samples had low haematocrit (Ht) values (<25%), whereas the other samples had normal Ht values.

    KEY FINDINGS: Measured tacrolimus ...

    Also Ranks for: Blood Tacrolimus |  preschool chromatography |  immunoassay acmia |  routine monitoring |  liver transplant
    KOL Index score: 5154

    Simultaneous determination of serum flecainide and its oxidative metabolites was carried out by using high performance liquid chromatography (HPLC) equipped with conventional octadecylsilyl silica (ODS) column and fluorescence detector. Flecainide and its metabolites, m-O-dealkylated flecainide (MODF) and m-O-dealkylated lactam of flecainide (MODLF) in serum were extracted with ethyl acetate. The recoveries of flecainide, MODF and MODLF were greater than 92, 93, and 60% with the ...

    Also Ranks for: Serum Flecainide |  simultaneous determination |  liquid chromatography |  concentration range |  arrhythmia agents
    KOL Index score: 4090

    AIMS: Statistically significant positive correlations are reported for the abundance of hepatic drug-metabolizing enzymes. We investigate, as an example, the impact of CYP3A4-CYP2C8 intercorrelation on the predicted interindividual variabilities of clearance and drug-drug interactions (DDIs) for repaglinide using physiologically based pharmacokinetic (PBPK) modelling.

    METHODS: PBPK modelling and simulation were employed using Simcyp Simulator (v15.1). Virtual populations were generated ...

    Also Ranks for: Drug Interactions |  cytochrome p450 |  predicted ddi |  cyp3a4 cyp2c8 |  enzyme abundance
    KOL Index score: 4003

    BACKGROUND: Therapeutic drug monitoring (TDM) and dose adjustment of lenvatinib may be beneficial in the treatment of radioiodine-refractory thyroid cancer, by maximizing antitumor effects and minimizing adverse drug reactions. The aim of this study was, therefore, to develop and validate a high-performance liquid chromatography method using an ultraviolet detection system for routine serum lenvatinib detection in patients with thyroid cancer.

    METHODS: Serum specimens, spiked with an ...

    Also Ranks for: Therapeutic Drug Monitoring |  liquid chromatography |  lower limit |  antitumor effects |  phenylurea compounds
    KOL Index score: 3906

    The reported therapeutic range for trough flecainide concentration is 200-1000 ng mL(-1). Severe adverse events, such as ventricular arrhythmias, have occurred occasionally in patients whose serum flecainide exceeded 1000 ng mL(-1). However, the lower limit remains controversial. We have evaluated blood flecainide concentrations in patients with tachyarrhythmia who received the drug to control palpitation. We measured the flecainide trough levels and incidence and frequency of ...

    Also Ranks for: Serum Flecainide |  concentrations 300 |  arrhythmia agents |  response relationship |  pressure liquid
    KOL Index score: 3756

    The chiral inversion kinetics of ibuprofen was evaluated after intraduodenal administration of racemic ibuprofen in conventional powder form and sustained-released granules compared with intravenous administration in rabbits. The AUC ratios of the S-(+) and R-(-) enantiomers remained almost constant values with time up to 2 h after administration of sustained-release formulation, while those after administration of the powder increased with time. R-(-) enantiomer to S-(+) enantiomer ...

    Also Ranks for: Absorption Rate |  chiral inversion |  intravenous administration |  ibuprofen rabbits |  stereoisomerism animals


    Kosuke Doki: Influence Statistics

    Sample of concepts for which Kosuke Doki is among the top experts in the world.
    Concept World rank
    flecainide clearance #4

    Key People For Cyp2d6 Genotype

    Top KOLs in the world
    Michel F Eichelbaum
    cytochrome p450 poor metabolizers genetic polymorphism
    Andrea Gaedigk
    cytochrome p450 cyp2d6 genotype xanthine oxidase
    cytochrome p450 drug metabolism genetic polymorphism
    Leif Bertilsson
    cytochrome p450 cerebrospinal fluid plasma levels
    Marja‐Liisa Dahl
    cytochrome p450 cyp2d6 genotype genetic polymorphism
    Matthias Schwab
    breast cancer cytochrome p450 personalized medicine

    Kosuke Doki:Expert Impact

    Concepts for whichKosuke Dokihas direct influence:Cyp2d6 genotype,  Flecainide clearance,  Serum flecainide,  Supraventricular tachyarrhythmia,  Flecainide enantiomers,  Scn5a promoter haplotype,  Flecainide metabolism,  Therapeutic drug monitoring.

    Kosuke Doki:KOL impact

    Concepts related to the work of other authors for whichfor which Kosuke Doki has influence:Drug interactions,  Cytochrome p450,  Delayed elimination,  Proton pump,  Cyp2d6 genotype,  Dose methotrexate,  Renal impairment.



    Is this your profile? manage_accounts Claim your profile content_copy Copy URL code Embed Link to your profile

    Department of Pharmaceutical Sciences, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan | Department of Pharmacy, University of Tsukuba Hospital, Tsukuba, Japan | Department of Pharmacy, University of Tsukuba Hospital, Ibaraki, Japan. | Dep