• Title/Summary/Keyword: pharmacodynamic

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Pharmacokinetic and Pharmacodynamic Modeling of Levodopa in Parkinson Disease

  • Holford, Nick H.
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.220-222
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    • 2002
  • The concentration effect relationship (pharmacokinetic pharmacodynamic model, PKPD) of drugs used for Parkinson's disease is complex. The benefits and adverse effects of drug treatment have to be considered in terms of short term and long term effects. Acute effects, observed over hours and days, reflect symptomatic benefit while chronic effects, observed over months and years, also reveal influences on the progress of the disease. (omitted)

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Pharmacodynamic and pharmacokinetic interactions between herbs andwestern drugs

  • Lee, Ju-Young
    • Advances in Traditional Medicine
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    • v.8 no.3
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    • pp.207-214
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    • 2008
  • In recent years, the combined use of Herbal medicines and Western drugs has been increasing. Though certain problems may occur when both types of medicines are taken together, they havenot been adequately analyzed. It was reported that anticoagulation was enhanced in addition tobleeding when patients took long-term warfarin therapy in combination with Salvia miltiorrhiza(danshen), and laxative herbs accelerate intestinal transit and interfere with the absorption. Herbal constituents, curcumin, ginsenosides, piperine, catechins and silymarin were found to beinhibitors of P-glycoprotein. St John's wort induces the intestinal expression of P-glycoprotein. Anthraquinone, quercetin and coumarins were found to be a potent inhibitor of P-450. Glycyrrhizin or liquorice extracts, Garlic and St John's wort are a potent inducer of CYP3A4. This review provides a critical overview of interactions between herbal medicines and other drugs. Hence, it is necessary to study the pharmacodynamic and pharmacokinetic interactions of many herbal medicines between western drugs.

Pharmacokinetic-Pharmacodynamic Modeling of a Direct Thrombin Inhibitor, Argatroban, in Rats

  • Park, Eun-Hye;Shin, Beom-Soo;Yun, Chi-Ho;Lee, Mann-Hyung;Yoo, Sun-Dong
    • Journal of Pharmaceutical Investigation
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    • v.39 no.5
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    • pp.373-379
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    • 2009
  • This study was conducted to develop a pharmacokinetic-pharmacodynamic (PK/PD) model of a direct thrombin inhibitor, argatroban to predict the concentration-effect profiles in rats. Argatroban was i.v. injected to rats at 0. 2, 0.8 and 3.2 mg/kg doses (n = 4-5 per dose), and plasma drug levels were determined by a validated LC/MS/MS assay. The pharmacokinetics of argatroban was linear over the i.v. dose range studied. The thrombin time (TT) and the activated partial thromboplastin time (aPTT) were measured in rat plasma and they were found to linearly increase with increasing the dose. A 2-compartment pharmacokinetic model linked with an indirect response pharmacodynamic model was successfully utilized to evaluate the drug concentration-response relationship.

Pharmacokinetic and Pharmacodynamic Modeling of a Proton Pump Inhibitor

  • Bae, Kyun-Seop;Jang, In-Jin
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.223-224
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    • 2002
  • Pharmacokinetic (PK) and pharmacodynamic (PD) study of a new reversible proton pump inhibitor (YH1885, Yuhan Pharmaceutical Co.) was done as a phase 1 clinical trial in Seoul national University Hospital Clinical trialcenter. Single dose of 60, 100, 150, 200, and 300mg were administered to total 20 healthy subjects under fasting state. Six subjects were given 100 mg after food and 12 subjects were given multiple doses of 150 and 300 mg every day for 7 days under fasting state. (omitted)

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Chiral Relevance of Stereoselective Disposition of Proton Pump Inhibitors: Comparision of Lansoprasole to Omeprazole and Pantoprazole

  • Shin, Jae-Gook
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.169-170
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    • 2002
  • It has been well known for the stereoselectivity in pharmacodynamic effects of many xenobiotics including therapeutic agents, which have lead to the development of enantiomer drugs. Compared to pharmacodynamic stereoselectivity, stereoselective pharmacokinetics of each enantiomer has not been seriously considered in the development of enantiomer drugs although many reports have been demonstrated the stereoselective absorption and metabolism of racemic drug (e.g verapamil). (omitted)

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Mechanistic Pharmacokinetic/pharmacodynamic Modeling in Isolated Perfused Organs and at the Whole-Body Level

  • Weiss, Michael
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.218-219
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    • 2002
  • In the past, the development of pharmacokinetic/pharmacodynamic (PK/PD) models for quantitating the time course of drug responses was mainly based on two types of models, the empirical effect compartment model that simply accounts for the delay between effect and plasma concentration (hysteresis) and the mechanism-based so-called indirect response model. The first approach traces back to a paper by Segre (1) and its application was popularized by Holford and Sheiner (2); indirect response models were introduced by Jusko's group (3). (omitted)

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Pharmacodynamic Modeling of Vincristine in Lymphoma Patients (림프종 환자에서 회귀모형을 이용한 vincristine의 약물 용량 예측 인자 및 부작용 모델 연구)

  • Seo, Jeong-Won;Kim, Dong-Hyun;Yun, Jin-Sang;Kim, Seon-Hwa;Choi, Bo-Yoon;Oh, Jung-Mi;Kwon, Kwang-Il
    • Korean Journal of Clinical Pharmacy
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    • v.21 no.2
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    • pp.145-155
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    • 2011
  • The objective of this study was to determine whether any pretreatment parameters were associated with pharmacological effect or toxicity parameters after vincristine administration and to describe a mathematical model, which explains the interpatient pharmacodynamic variability. The relationship between patient characteristics and vincristine dose and hematological toxicity were evaluated. 68 pediatric and adolescence patients and 107 adults with acute lymphoblastic leukemia were treated with vincristine $1.5mg/m^2/day$ IV and other anticancer drugs as scheduled. Complete blood counts and other blood test results were obtained. The input variables were age, gender, weight, lean body weight (LBW), height, body surface area, vincristine dose and total vincristine dose. The outcome measures were nadir values (white blood cells, absolute neutrophil counts, hemoglobin, and platelets); the absolute decrease, relative decrease, and survival fraction of blood cells. Polynomial regression analysis was carried out to determine the other significant covariates. The variability of $WBC_{nadir}$ was modeled with good precision and accuracy with a two-covariate model. This model should be validated and improved on with further clinical data. We believe that such pharmacodynamic modeling should be explored further to determine its performance and clinical relevance compared with modeling using pharmacokinetic parameter.

Clinical Evaluation of a Low-pain Long Microneedle for Subcutaneous Insulin Injection

  • Lee, Ghunil;Ma, Yonghao;Lee, Yong-ho;Jung, Hyungil
    • BioChip Journal
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    • v.12 no.4
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    • pp.309-316
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    • 2018
  • Microneedles (MNs) are being developed to overcome the limitations of the conventional hypodermic needle, e.g. the injection pain. In this study, we conducted an analysis of clinical pain and bleeding at the site of MN insertion and evaluated the insulin pharmacodynamic profile compared with parameters obtained with a conventional pen needle. MN insertion into the skin of 25 healthy adults or 15 patients with type 2 diabetes (T2D) revealed significantly less pain relative to a conventional hypodermic pen needle, thus reducing pain scores from $2.1{\pm}1.9$ to $21.3{\pm}1.4$ ($mean{\pm}standard$ deviation [SD]). Besides, no bleeding was observed when the MN was used. In the insulin pharmacodynamic assay, no significant differences were observed in the blood glucose-lowering effect between the pen needle and MN. Based on these results, the MN is expected to be a good substitute for conventional hypodermic pen needles and improve the quality of life of patients by significantly reducing the pain associated with insulin treatment.