• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.330-335
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• 2004

Phase specific models for cancer chemotherapy are described as optimal control problems. We review earlier results on scheduling optimal therapies when the controls represent the effectiveness of chemotherapeutic agents, or, equivalently, when the simplifying assumption is made that drugs act instantaneously. In this paper we discuss how to incorporate more realistic medical aspects which hitherto have been neglected in the models. They include pharmacokinetic equations (PK) which model the drug's plasma concentration and various pharmacodynamic models (PD) which describe the effect the concentrations have on cells. We also briefly discuss the important medical issue of drug resistance.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.11a
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• pp.87-91
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• 1997

The range of disorders of old age that are thought potentially amenable to drug therapy is increasing. However, factors such as the growing costs of drug development and prescription, the novel pharmacological profile and enhanced potency of many new compounds, and the concerns that the elderly may have enhanced susceptibility to toxicity all make drug usage in the elderly patient an increasingly specialized topic. This is compounded by the high incidence of multiple disorders in frail elderly patients, and consequently the possibility of the long term use of several drugs, thus, adding the risk of drug interactions. Thus, clinical pharmacology in the elderly requires understanding of pharmacologic characteristic determinants of the physiological changes (Table 1) associated with aging in terms of pharmacokinetics and pharmacodynamics.

• 대한임상약리학회:학술대회논문집
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• 2003.12a
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• pp.19-19
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• 2003

• Korean Journal of Psychosomatic Medicine
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• v.1 no.1
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• pp.92-97
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• 1993

Successful management of mental symptoms requires proper diagnostic tools and comprehensive treatment including psychotherapy, physical therapy and psychopharmacotherapy. For this purpose. valid and reliable diagnostic instruments need to be developed. and the data regarding various treatment methods in medical and psychiatric comorbid conditions should be available. Because mental symptoms originate from various aspects of biological, psychological and social factors. each aspect may have slightly different therapeutic goal. Alterations in pharmacokinetics and pharmacodynamics of medically ill and/or old patients may complicate the treatment outcomes. Best psychopharmacological treatment needs to be elaborated in various states. Mental symptoms of the medically ill patients may be treated more effectively with an eclectic approach.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.2
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• pp.97-106
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• 2012

The pharmacokinetics/pharmacodynamics analysis software NONMEM$^{(R)}$ output provides model parameter estimates and associated standard errors. However, the standard error of empirical Bayes estimates of inter-subject variability is not available. A simple and direct method for estimating standard error of the empirical Bayes estimates of inter-subject variability using the NONMEM$^{(R)}$ VI internal matrix POSTV is developed and applied to several pharmacokinetic models using intensively or sparsely sampled data for demonstration and to evaluate performance. The computed standard error is in general similar to the results from other post-processing methods and the degree of difference, if any, depends on the employed estimation options.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.212-213
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• 2002

Using the isolated perfused rat heart this study investigated 1) the cardiac uptake of idarubicin (IDA), 2) the role of P-glycoprotein (P-gp) in the uptake process, 3) the formation of IDOL from IDA in the heart, and 4) the effect of P-gp inhibitors (verapamil, amiodarone, PSC 833), doxorubicin, hypothermia, xanthine derivatives (caffeine, theophylline) and metabolism inhibitors (rutin, phenobarbital) on the pharmacokinetics and pharmacodynamics of IDA using a mathematical modeling approach. A minimal model was constructed; the differential equations were numerically solved and fitted to the data using the ADAPT II-software package using maximum likelihood estimation assuming that the measurement error has a standard deviation which is a linear function of the measured quantity［1］. (omitted)

• East Asian mathematical journal
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• v.36 no.1
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• pp.81-90
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• 2020

Many compartment models assume a kinetically homogeneous amount of materials that have well-stirred compartments. However, based on observations from such processes, they have been heuristically fitted by exponential or gamma distributions even though biological media are inhomogeneous in real environments. Fractional differential equations using a specific kernel in Pharmacokinetic/Pharmacodynamic (PKPD) model are recently introduced to account for abnormal drug disposition. We discuss a tumor growth inhibition (TGI) model using fractional-order derivative from it. This represents a tumor growth delay by cytotoxic agents and additionally show variations in the equilibrium points by the change of fractional order. The result indicates that the equilibrium depends on the tumor size as well as a change of the fractional order. We find that the smaller the fractional order, the smaller the equilibrium value. However, a difference of them is the number of concavities and this indicates that TGI over time profile for fitting or prediction should be determined properly either fractional order or tumor sizes according to the number of concavities shown in experimental data.

• Korean Journal of Biological Psychiatry
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• v.5 no.1
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• pp.56-65
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• 1998

Clinicians can use therapeutic drug monitoring(TDM) to optimise dosage decisions with psychotropic drugs, in order to maximize efficacy and prevent toxicity, especially when individuals are nonresponsive to treatment or vulnerable to adverse reactions with standard doses because age, disease states or drug interactions. Currently, therapeutic drug concentrations have been established for the TCA and lithium. There is also evidence for the usefulness of TDM with carbamazepine, valproic acid and some antipsychotic drugs. However for most psychotropic drugs this approach remains experimental. TDM-assisted psychiatric treatment is potentially useful and cost effective, particularly when applied by psychiatrists who are knowledgeable of pharmacokinetics and pharmacodynamics.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.10a
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• pp.135-136
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• 1995

Resent advances in computer technology have introduced a sophisticated capability for computing the biological fate of toxicants in a biological system. This methodology, which has drastically altered risk assessment skill in toxicology, is designed using all the mechanistic information, and all claim better accuracy with extrapolating capability Iron animal to people than conventional pharmacokinetic methods. Biologically based mathematical models in which the specific mechanistic steps governing tissue disposition(pharmacokinetics) and toxic action (pharmacodynamics) of chemicals are constructed in quantitative terms by a set of equations loading to prediction of the outcome of specific toxicological experiments by computer simulation. pharmacokinetic and pharmacodynamic models are useful in risk assessment because their mechanistic biological basis permits the high-to-low dose, route to route and interspecies extrapolation of the tissue disposition and toxic action of chemicals.

• Korean Journal of Biological Psychiatry
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• v.5 no.2
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• pp.155-161
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• 1998

Mood disorder is a medical illness resulting from the disorder of CNS neurotransmission and its principal therapeutic tool is pharmacotherapy. Psychotherapeutic drugs for mood disorder have some clinical limitations which are due to no or partial response, decreased compliance for drug by the side effects, and delayed therapeutic effects. So, general hope of all clinicians that mood diorder will respond to a single psychotherapeutic agent may be the exception rather than the rule. Recently, combined drug treatments have become increasingly popular to overcome the clinical limitations of individual agent in mood disorder. Combined treatments are usually used for augmenting or initiating rapidly the effect of drug, and for treating different target symptoms or drug side effects. When combined treatments being tried, knowledge of the action mechanism, pharmacokinetics, and pharmacodynamics is crucial to cope with the possible adverse reactions of drugs.