pharmacokinetics

..Forgiveness is the property of a drug which, when compared with another medicine with different pharmacokinetics and/or concentration-effect relationships, blunts the consequences of missing one or two doses in a row, or ..

Physiologic alterations in critically ill patients can significantly affect the pharmacokinetics of drugs used in the critically ill patient population...

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..This will give rise to new opportunities of drug combinations, which can only be developed rationally through the appropriate application of dynamical systems-based PK/PD models...

..To present a framework within which population pharmacokinetic (PPK) studies should be designed and analyzed and discuss the application of developed PPK models...

..In addition to modeling of drug disposition (PK) pathways, we emphasize the need for modeling of effect (PD) pathways and the use of a multidisciplinary infrastructure for data-sharing...

..75 should be replaced by the exponent of the allometric equation developed for that drug...

..In addition, by providing a link between tissue concentrations and toxicological or pharmacological effects, PBPK modeling represents a framework for mechanistic pharmacokinetic-pharmacodynamic models...

..This review summarizes the sex-based differences that impact on pharmacokinetics, and includes a general comparison of clinical pharmacology as it applies to men, women and pregnant women...

..Hence drugs should be used very restrictively in geriatric patients. If drug therapy is absolutely necessary, the dosage should be titrated to a clearly defined clinical or biochemical therapeutic goal starting from a low initial dose...

..Physiologically based pharmacokinetics is one way to integrate the physiological changes occurring in the childhood and to anticipate their impact ..

..However, following such an exercise, well-conducted PK-PD or PK studies will still be needed to determine the most appropriate doses for neonates, infants, children and adolescents...

..A sigmoid E(max) model (Hill equation) describes gradual maturation of clearance in early life leading to a mature adult clearance achieved at a later age...

..15 patients with acute hepatitis C (AHC) among 29 healthy volunteers participating in 2 consecutive pharmacokinetics studies...

..Ocular drug delivery is hampered by the barriers protecting the eye. This review presents an overview of the essential factors in ocular pharmacokinetics and selected pharmacological future challenges in ophthalmology.

..This has yielded models with much-improved properties for extrapolation and prediction. These models constitute a theoretical basis for rational drug discovery and development...

..The relative role of sex on pharmacokinetics as compared to genetics, age, disease, social habits and their potential interactions in the clinical setting ..

..polypeptides (OATP) form a family of influx transporters expressed in various tissues important for pharmacokinetics. Of the 11 human OATP transporters, OATP1B1, OATP1B3 and OATP2B1 are expressed on the sinusoidal membrane of ..

..This method creates a hydrophilic protective layer around the nanoparticles that is able to repel the absorption of opsonin proteins via steric repulsion forces, thereby blocking and delaying the first step in the opsonization process...

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..That is, high fat meals and lipidic excipients would be expected to have little effect on F for Class 1 drugs; they would increase F of Class 2 drugs, while decreasing F for Class 3 drugs...

..This optimization and proof of principle study demonstrates that biodistribution and pharmacokinetics of siRNA and the corresponding polyplexes can be determined using SPECT, leading to comparable results as ..

..Our findings demonstrate for the first time that the administration of multiple flavonoids results in increased flavonoid bioavailability, as well as a decrease in clearance, potentially due to increased enterohepatic cycling...

..Disease state, as exemplified by obesity, was addressed as a modifier of drug pharmacokinetics and pharmacodynamics during development...

..Finally, the ability of these prediction tools, when placed within a generic whole body physiologically based model of pharmacokinetics, to predict plasma concentration-time profiles is briefly discussed.

Generic physiologically-based models of pharmacokinetics were evaluated for early drug discovery. Plasma profiles after intravenous and oral dosing were simulated in rat for 68 compounds from six chemical classes...

..We conclude that equivalent plasma drug concentrations and metabolic profiles can be expected for native Japanese, first- and third-generation Japanese, Koreans, and Chinese for compounds handled through these six CYP enzymes...

..The integration of these guidelines, and combining them with pharmacodynamic effects, should be considered and could form a basis for further study...

In people who are aged >65 years, pharmacokinetics are influenced more by the loss of kidney function than by the aging process of any other organ...

..This review describes the framework and organisation of the simulator and how it combines the different categories of information...

The pharmacokinetics and pharmacodynamics of drugs are different in adult and paediatric populations, the latter being particularly heterogeneous...

..enough evidence from experimental data that negate the notion of fixed exponents in biology, physiology, and pharmacokinetics. In short, the notion of a fixed exponent is theoretical and there is no evidence that the exponent of a ..

..Plerixafor was safe and effective in mobilizing CD34(+) cells for transplantation...

..presenting the theory, we study, here, through practical examples, the potential of such methods in toxico/pharmacokinetics. As a tutorial, we first simplify a 2-compartment pharmacokinetic model by symbolic lumping...

P-glycoprotein (P-gp), an efflux transporter, controls the pharmacokinetics of various compounds under physiological conditions...

The application of population pharmacokinetics (PopPK) appears increasingly in drug labelling. The current study was to examine the use of PopPK in dose recommendation in drug-product labels.

..a common guideline for prescribing "off-label" in pediatrics, but must be used in combination with multiple respected pediatric resources and with full knowledge of pharmacokinetics in children, particularly in young children.

..of the drive to decrease this failure rate in drug development involves attempts to use physiologically-based pharmacokinetics 'bottom-up' modeling and simulation to optimize molecular features with respect to the absorption, ..

..Utilizing WRES with the FOCE method may lead to misguided model development/evaluation. We present a new diagnostic tool, the conditional weighted residuals (CWRES), which are calculated based on the FOCE approximation...

..The net effect is an increased degree of hypouricaemia, but the interaction is probably limited to patients with normal renal function or only moderate impairment...

Modeling and simulation in pharmacokinetics has turned into the focus of pharmaceutical companies, driven by the emerging consensus that in silico predictions, combined with in vitro data, have the potential to significantly increase ..

..variances in the genes of membrane transporters could explain at least in part interindividual differences of pharmacokinetics and clinical outcome of a variety of drugs...

..Such advancements in parameter prediction will assist WBPBPK modelling, where time, cost and labour requirements greatly deter its application...

..function changes drastically by age, drug therapy should be arranged according to the age-related changes in pharmacokinetics of its age...

..Nonparametric methods are better than parametric methods at analysing populations having unanticipated non-Gaussian or multimodal parameter distributions...

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..As a consequence of its favourable pharmacokinetic and pharmacodynamic properties, ximelagatran is currently undergoing full-scale clinical development for the prophylaxis and treatment of thromboembolic disorders...

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We use mathematical modelling to delineate the influence of two important factors on local pharmacokinetics of a drug delivered via an eluting stent, namely: (1) diffusional resistance of a stent coating, and (2) reversible binding of a ..

..Through linking of in silico and in vitro methods, considerable progress has recently been made towards this future perspective. Despite this progress, these approaches do not yet replace in vivo methods...

..Finally, some attention is given to the positioning of PBPK within the drug development and approval paradigm and its future application in truly personalized medicine...

..The pharmacokinetics of trans-resveratrol have been investigated in single-dose studies and in studies with relatively low dosages...

..5th and 97.5th percentiles of the parameter space. The performance of the proposed optimality criteria is compared to two existing robust optimal design criteria...

..Certain preliminary information, such as the compartment model used in describing the pharmacokinetics of the drug, is required for a population pharmacokinetic study...

..All together, these data justify why studying drug active transport should be part of the evaluation of new drugs, as recently recommended by the FDA...

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..Although robustness and reliability are important concerns, they were not addressed in the present review. Most of the programs surveyed are in continual development...

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..The rationale for using these indexes is shown using simulated and real data...

..However, several important issues remain to be resolved (such as the optimal study design, quality of the data and user-friendly software) which could determine the future role of the population approach in drug development...

..This variation has been recognized to be due, in part, to the wide variation in the pharmacokinetics (PK) of high-dose chemotherapy (HDC)...

..It is concluded that an oil/water nanoemulsion system with good biocompatibility can be prepared by using food proteins as emulsifiers, allowing better and more rapid absorption of lipophilic drugs...

..As toxicology is a continuum of pharmacokinetics and pharmacodynamics, this is a review of recent advances on pharmacokinetics and physiologically-based ..

..In the future we could see ADME properties designed-in from the first principles in drug design...

..4. This review highlights the emerging role of transport proteins in ADE of drugs and suggests these need to be considered, in drug discovery and development, with respect to variability in drug disposition and response...

..changes in gastric emptying time, gastric pH and/or intestinal fluid composition may have an impact on the pharmacokinetics of drugs...

..However, the quantitative output of the methods has to be improved. The aim of this review is to highlight the practical and theoretical basis of the in vitro metabolic methods and the recent progress in the development of these assays...

..Theoretical models for predicting absorption, distribution, metabolism and excretion (ADME) properties play increasingly important roles in support of the drug development process...

..Highest variability was for IC (50) and SC (50) parameters. This study provides new insights into optimum study designs and recovery of parameters for basic IDR models...

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..However, it has been difficult to locate reliable models for the prediction of human pharmacokinetics (PK) in silico Currently available methods for estimating ADME and toxicity properties, such as in vitro and ..

..In addition, collaboration to apply novel methods such as metabonomics profiling to withdrawn drugs may permit the identification of new safety biomarkers to prevent such costly failures...

..but the factors related to the gastrointestinal tract and the dynamic nature of drug dissolution and systemic pharmacokinetics are not taken into account...

..The stage is set for a wide penetration of PK modeling and simulations to form an intrinsic part of a project starting from lead discovery, to lead optimization and candidate selection, to preclinical profiling and clinical trials...

..5 of the drug, and the drug concentration at the peaks defined as a fraction of the first unchanged peak concentration...

..AVAILABILITY: http://www.pkdb.ifsc.usp.br..

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..The review thus summarizes recent advances and presents a viewpoint on improvements envisioned in the years to come for automated computer aided lead molecule discovery...

N-in-1 (or cassette) dosing pharmacokinetics (PK) has been used in drug discovery for rapid assessment of PK properties of new chemical entities...

Three advanced models of pharmacokinetics are described. In the first class are physiologically based pharmacokinetic models based on in vitro data on transport and metabolism...

..Predictions of in-vivo dissolution should preferably be done from in-vitro dissolution data obtained using either real or validated simulated GI fluids...

Pharmacokinetic and pharmacodynamic changes occur with increasing age. Sex differences in pharmacokinetics and pharmacodynamics exist and persist at older age...

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..The significance of the stereochemical aspects of pharmacokinetics and drug metabolism in both preclinical and clinical development is summarized and illustrated with reference ..

..The computational model described can predict human VD(ss) with an accuracy comparable to predictions requiring substantially greater effort and can be applied in place of animal experimentation...

..CONCLUSION: The in vitro transcellular transport across P-gp expressing monolayers may be used to predict the extent to which the intestinal absorption is affected by P-gp...

..In addition, several methods of integrating ADME properties to predict pharmacokinetics at the organ or body level have been studied. In this article, we briefly summarize in silico ADME approaches.

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..The quantitative relation between the duration of the input and the accuracy of r is unknown. Although a large number of deconvolution procedures have been described, these routines are not available in a convenient software package...

..Thus, it was shown that, using a combination of only two computational molecular descriptors, it is possible to predict with good accuracy the K(a) value for a new drug candidate...

..The simulations further showed that a descending metabolic intrinsic clearance yielded a lower F and an ascending segmental distribution of metabolic intrinsic clearance yielded a higher F...

This competitive renewal application is to define the pharmacokinetics and pharmacodynamics of the drugs commonly used in intravesical therapy, in order to optimize the treatment regimen...

..Also to determine the toxicity, pharmacokinetics, metabolism of AuNP and finally test its efficacy as anti-angiogenic agent to inhibit tumor growth and ..

..efflux proteins, P- gp and/or MRP, expressed on the retinal pigmented epithelium (RPE), and thus alter ocular pharmacokinetics of systemically/intravitreally co-administered substrates...

..Currently, the pharmacokinetics, safety, and biologic effects of azithromycin in the preterm population are unknown...

..aims of this research are 1) to evaluate the potential for CB-drug interactions and 2) to determine the pharmacokinetics and renal clearance of four major CB flavonoids...

..Vaccines which alter drug pharmacokinetics have shown substantial preclinical and preliminary clinical evidence of efficacy for nicotine and cocaine ..

..cytochrome P450 enzymes are so homologous that pigs should be the preferred model for drug metabolism and pharmacokinetics studies. Yet, pigs are under-utilized...

..IND) application, the First in Man Phase I dose escalation clinical trial to assess safety, tolerability and pharmacokinetics after a single oral dose will be conducted in the United States in healthy volunteers...

..Alternatively, it may be an effect of obesity to confound the leukemia treatment, possibly due to altered pharmacokinetics of chemotherapeutic agents...

..2) Evaluate the pharmacokinetics and safety of bumetanide (BTN) in newborns with refractory seizures caused by HIE in a Phase I Trial...